Pressure contact terminal for superconducting transmission lines, and manufacturing the same

Abstract

Embodiments described herein include a contact terminal configured to be disposed around a portion of a conductive elongate member. The contact terminal may include an inner sleeve including a first end portion, a second end portion, and a central portion therebetween. The contact terminal may include a pair of outer sleeves configured to be disposed around the first end portion and the second end portion. The inner sleeve may define one or more slots and taper from the central portion to each of the first end portion and the second end portion. The inner sleeve may deform to distribute a clamping pressure to the portion of the conductive elongate member. The inner sleeve and the outer sleeve may include a conductive material such that a current can be injected or withdrawn from the conductive elongate member.

Description

PRESSURE CONTACT TERMINAL FOR SUPERCONDUCTING TRANSMISSION LINES, AND MANUFACTURING THE SAMECROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit of U.S. Provisional Application No. 63 / 710,486, filed on October 22, 2024, and entitled “Pressure Contact Terminal for Superconducting Transmission Lines, and Manufacturing the Same”, the content of which is hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] Embodiments described herein relate to terminals for inputting and outputting current from superconducting transmission lines, and methods of manufacturing the same.BACKGROUND

[0003] Conventional methods of injecting or extracting current form superconducting cables includes using solder pots, solder vacuum impregnation, or soldering each conductor to buswork. While these methods provide low resistance contact to inject current, these methods also require the use of heaters, vacuum pumps, and / or melted / liquid solders, thereby increasing the complexity and reducing the repeatability of forming the connection between the terminal to the cable and the terminal to external devices.SUMMARY

[0004] In some embodiments, an apparatus includes an inner sleeve including a first end portion, a second end portion, and a central portion between the first end portion and the second end portion. The inner sleeve defines an inner volume configured to receive a portion of a conductive elongate member. A first outer sleeve is configured to be disposed around the first end portion of the inner sleeve and a second outer sleeve configured to be disposed around the second end portion. The inner sleeve defines one or more slots and tapers from the central portion to each of the first end portion and the second end portion such that when the first outer sleeve and the second outer sleeve are disposed around the inner sleeve, the inner sleeve deforms to distributes a clamping pressure to the portion of the conductive elongate member.The inner sleeve and the outer sleeves include a conductive material such that a current can be injected or withdrawn from the conductive elongate member.[0005 | In some embodiments, an apparatus includes an inner sleeve defining an inner volume configured to receive a conductive elongate member. The inner sleeve has a first tapered portion and a second tapered portion. A wide end of the second tapered portion is coupled to and abuts a narrow end of the first tapered portion. A first outer sleeve is configured to be disposed around the first tapered portion. The first tapered portion defines a plurality of slots such that, when the first outer sleeve is disposed around the first tapered portion, the first tapered portion deforms to distributes a clamping pressure to a first portion of the conductive elongate member. A second outer sleeve is configured to be disposed around the second tapered portion. The second tapered portion defines a plurality of slots such that, when the second outer sleeve is disposed around the second tapered portion, the second tapered portion deforms to distributes a clamping pressure to a second portion of the conductive elongate member. An end cap can be coupled to a terminal end of the conductive elongate member.

[0006] In some embodiments, a method includes disposing a fill material around a portion of a conductive elongate member; disposing an inner sleeve around the fill material, the inner sleeve including a first end portion, a second end portion, and a central portion; disposing a first outer sleeve around the first end portion of the inner sleeve and a second outer sleeve around the second end portion of the inner sleeve; and coupling the first outer sleeve to the second outer sleeve such that the inner sleeve applies a substantially uniform pressure to the conductive elongate member. In some embodiments, the method can further include disposing a conductive tube around the fill material to at least partially cover the fill material prior to disposing the inner sleeve. In some embodiments, the method can further include injecting a current into or withdrawing a current from the conductive elongate member.BRIEF DESCRIPTION OF THE DRAWINGS[00Q7| FIG. 1 is a schematic block diagram of a terminal configured to be coupled to a conductive elongate member, according to an embodiment.

[0008] FIG. 2 is a schematic block diagram of a terminal configured to be coupled to a conductive elongate member, according to an embodiment.[0009| FIG. 3 is a side view illustration of an inner sleeve of a terminal including tapered first and second end portions, and a central portion extending therebetween, according to an embodiment.

[0010] FIGS. 4A-4C show schematic diagrams of a contact terminal configured to apply substantially uniform clamping pressure to a portion of a conductive elongate member, according to an embodiment.

[0011] FIG. 5 is a perspective view of an inner sleeve of a terminal configured to be coupled to a conductive elongate member, according to an embodiment.

[0012] FIGS. 6A shows a side view of the inner sleeve of FIG. 5. FIG. 6B show a cross-sectional view of the inner sleeve, according to an embodiment.[0013| FIG. 7 is a front view of the inner sleeve of the terminal, according to an embodiment.

[0014] FIG. 8 shows a perspective view of an outer sleeve of a terminal, according to an embodiment.[O015] FIGS. 9A-9C show a front view, a cross-sectional side view, and a top view, respectively, of the outer sleeve of the terminal, according to an embodiment.

[0016] FIG. 10 shows a terminal including an inner sleeve and an outer sleeve disposed around a terminal end of a conductive elongate member, according to an embodiment.[00171 FIG. 11 is a schematic diagram of a terminal including a plurality of inner sleeve portions coupled to an end cap, according to an embodiment.[0O18| FIG. 12 is a perspective view of a terminal including a plurality of inner sleeve portions coupled to an end cap and a plurality of outer sleeve portions, according to an embodiment.

[0019] FIG. 13 shows a perspective view of an outer sleeve of a terminal configured to be coupled to a conductive elongate member, according to an embodiment.

[0020] FIGS. 14A-14C show a front view, a cross-sectional side view, and a top view, respectively, of the outer sleeve of the terminal of FIG. 13[0021| FIG. 15 shows a terminal configured to be coupled to a conductive elongate member, according to an embodiment.[0022| FIG. 16 shows a terminal disposed around a terminal end of a superconducting cable, according to an embodiment.[00231 FIG. 17 shows a front view of an outer sleeve of a terminal configured to be coupled to a conductive elongate member, according to an embodiment.

[0024] FIG. 18 is a schematic block diagram of a terminal coupled to a conductive elongate member, according to an embodiment.

[0025] FIG. 19 is a cross-sectional view of a terminal disposed around a terminal end of a conductive elongate member, according to an embodiment.

[0026] FIG. 20A is an illustration of a portion of a terminal disposed around a terminal end of the conductive elongate member, according to an embodiment. FIG. 20B is an illustration of a portion of the terminal shown in FIG. 20 A.

[0027] FIG. 21 is a flow chart diagram of an example method of coupling a terminal to a conductive elongate member, according to an embodiment.DETAILED DESCRIPTION

[0028] A termination (i.e., a terminal) is used at one or both ends of a cable (e.g., superconducting cable) to inject current into and / or extract current from the cable. For superconducting cables, these terminals should be capable of carrying the same amount of current as the superconducting cable while limiting heat dissipation (e.g., by lowering contact resistance between the terminal and the cable). The terminals are often applied at height by linemen, so it is desirable to have as simple and repeatable a terminal as possible. Current methods for applying terminals to a cable include dipping the end of the cable into a solder pot (e.g., a copper can) containing melted solder and disposing an outer fixture over the solder-coated cable end. In some methods, a vacuum force can be applied to reduce the contact resistance in the terminal. Other methods include soldering each conductor to buswork. These methods have drawbacks including: (1) difficult installation due to the use of a variety of equipment (e.g., heaters, vacuum pumps) and melted / liquid solders; (2) difficult repeatability in forming the electrical connection between the cable and the terminal; and (3) lower consistency in electrical properties across different terminals.

[0029] In contrast, embodiments described herein include a terminal configured to apply a uniform contact pressure without using heat or applying a vacuum. In some embodiments, the terminal may be configured to couple to the cable such that electrical connections are formedwithout using liquid solder. Embodiments described herein use pressure as the main connection for a current contact for conductive cables (e.g., a helically wound superconducting transmission cable). In some embodiments, the terminal can produce a large clamping force with accurate alignment relative to the cable. In some embodiments, the terminal may achieve a substantially uniform clamping pressure around the cable core providing a uniform and low contact resistance. The terminal may include an inner sleeve (e.g., a slotted spindle with tapered edges) and two or more outer sleeves (e.g., hexes), which when clamped together can compress the inner sleeve onto the cable core. These terminals may deliver uniform and sufficiently low contact resistance between tapes disposed around a core of a superconducting cable and the terminal.

[0030] In some embodiments, the terminal may be configured to accommodate multi-layer (e.g., coaxial, triaxial, quadriaxial, etc.) cables. For example, a multilayer terminal may include a plurality of inner sleeves (e.g., a “half collet”) each configured to be disposed around a respective layer of the cable. Each inner sleeve may be compressed by a respective outer sleeve (e.g., hex) disposed around a portion of the inner sleeve. The plurality of inner sleeves allows for variances and / or account for tolerances in the cable diameters, providing flexibility in the terminal fit and ensuring a consistent pressure and contact resistance on each layer.

[0031] The embodiments described herein may provide the following advantages: (1) low contact resistance connection; (2) uniform contact resistance across terminal; (3) clamping pressure held within a tight range to prevent cracking of superconducting cable (4) no use of heat during installation; (3) repeatable installation; (5) less equipment for installation; and (6) easy to install in the field.

[0032] As described herein, “terminal” refers to a component coupled or coupleable to a cable in which current is injected or extracted from the cable (e g., the superconducting components). As used herein, “contact terminal” refers to a terminal that forms an electrically conductive pathway between the cable and the terminal by applying a clamping pressure (e.g., contact pressure, clamping force, etc.) to the cable.

[0033] FIG. 1 is a schematic block diagram of a terminal 100 (e.g., a contact terminal) for a conductive elongate member 150, according to embodiments. In some embodiments, the conductive elongate member 150 may include a superconducting cable. The superconducting cable may include a former (e.g., about 1 inch in diameter) and a plurality of superconducting bands or tapes wrapped helically around or otherwise conforming to the former. Thesuperconducting bands may be wrapped and / or disposed around the former in one or more layers. In some embodiments, the superconducting cable may be configured to carry a single electrical phase (e.g., the superconducting bands may all be electrically coupled). In other embodiments, the superconducting cable may be configured to carry multiple electrical phases (e.g., multiple superconducting layers within the cable may be electrically isolated, for example, in a coaxial, triaxial, quadriaxial, etc. configuration). In some embodiments, the superconducting bands may be fixed to one or both terminal ends of the cable. A terminal 100 may be configured to be disposed over one or both terminal ends of the cable (e.g., where the superconducting bands are fixed to the terminal end of the cable).[0034 | In some embodiments, the terminal 100 may include one or more inner sleeves configured to be disposed around a portion of the conductive elongate member 150. In some embodiments, the inner sleeve 110 may define an inner volume configured to receive a portion of a conductive elongate member 150. For example, the inner surface of the inner sleeve 110 may form a substantially cylindrical shape, and an inner diameter of the inner sleeve 110 may correspond to an outer diameter of the conductive elongate member 150. The terminal 100 may further include one or more outer sleeves 120 configured to be disposed around at least a portion of the inner sleeve(s) 110. The outer sleeve(s) 120 may optionally include one or more mating features 130 coupled to (e.g., disposed on, defined by, extending through) an outer surface thereof and configured to electrically connect the conductive elongate member 150 to an external component or device. For example, the mating features 130 may be configured to electrically connect the conductive elongate member 150 to a current source and / or current sink (e.g., a busbar, copper wire, a cable, etc.) such that current can be injected into and / or extracted from the conductive elongate member 150. In some embodiments, the terminal 100 may optionally include an end cap 170 disposed on a terminal end thereof. The end cap may urge the outer sleeve 120 up a tapered portion of the inner sleeve 110. For example, the outer sleeve 120 may be coupled or tightened to the end cap 170 such that the outer sleeve 120 moves up the tapered portion of the inner sleeve 110 to compress the inner sleeve 110.

[0035] In some embodiments, the terminal 100 may include one inner sleeve 110 configured to receive a portion of the conductive elongate member 150. In some embodiments, the terminal 100 may include a plurality' of inner sleeves 110, with each inner sleeve 110 disposed around a portion of the conductive elongate member 150. For example, each inner sleeve may be electrically isolated and configured to couple to a different portion of the conductive elongate member 150 configured to carry a different electrical phase. The terminal100 may be configured to cover a predetermined length of the conductive elongate member 150. In some embodiments, the contact terminal 100 may cover between about 2 in to about 12 in of the conductive elongate member 150, inclusive of all ranges and subranges therebetween. In some embodiments, a length the contact terminal 100 may depend on a number of layers of the conductive elongate member 150 the contact terminal 100 covers. In some embodiments, a minimum contact terminal length per layer may be about 2 inches. In some embodiments, a contact terminal 100 configured to be disposed around 1 layer of a conductive elongate member 150 may have a length of about 2 inches. In some embodiments, a contact terminal 100 configured to be disposed around 6 layers of a conductive elongate member may be about 12 inches. In some embodiments, a contact terminal 100 configured to be disposed around more than 6 layers may be longer than 12 inches. In some embodiments, a maximum contact terminal length per layer may be about 8 inches.[0036J In some embodiments, the terminal 100 may include an inner sleeve 110 including a first end portion, a second end portion, and a central portion extending between the first end portion and the second end portion. The inner sleeve 110 may include one or more tapered portions. For example, the inner sleeve 110 may have a cylindrical inner diameter configured to be positioned over a cylindrical conductive elongate member 150 and the outer diameters of the first end portion and the second end portion may each taper from the central portion to a terminal end of each of the first end portion and the second end portion, as described in further detail with respect to FIGS. 3-6C. In some embodiments, the first end portion and the second end portion may have a predetermined taper angle configured to accommodate a range of conductive elongate member diameters.[0037| In some embodiments, the inner sleeve(s) 110 may define one or more slot(s) 118. For example, a surface of the inner sleeve(s) 110 may define slots 118 extending longitudinally along a length of the inner sleeve(s) 110. A width of the slot(s) 118 and a distance between adjacent slot(s) 118 may be configured such that the inner sleeve(s) 110 has a desired deformabilifi’ (e.g., flexibility). In some embodiments, the slot(s) 118 may allow the inner sleeve(s) 110 to deform to a shape of the conductive elongate member 150 and / or apply a substantially uniform radial force to the conductive elongate member 150 such that an inner surface of the inner sleeve(s) 110 contact an outer and / or exposed surface of the portion of the conductive elongate member 150. In some embodiments, the inner sleeve(s) 110 may include any suitable number of slots 118. For example, the inner sleeve(s) 110 may include between about 3 and about 40 slots, inclusive of all ranges and subranges therebetween. In someembodiments, the inner sleeve(s) 110 may include between about 4 slots and about 16 slots, inclusive of all ranges and subranges therebetween. Further details around the slot(s) 118 are described with respect to FIGS. 5-6B. Similarly stated, the inner sleeve 110 may have the structure and / or function of a collet /

[0038] In some embodiments, the taper angle and / or configuration of the slot(s) 118 (e.g., the number, size, and spacing of the slot 118) may allow the inner sleeve(s) 110 to deform to the conductive elongate member and / or distribute a substantially uniform radial clamping pressure to the portion of the conductive elongate member disposed in the inner volume of the inner sleeve 110. The inner sleeve(s) 110 may have a predetermined deformability (e.g., flexibility) such that the inner sleeve(s) can fit to different cable diameters. In some embodiments, the inner sleeve(s) 110 may be configured to be disposed around different cables having different diameters. In some embodiments, the inner sleeve(s) 110 may be configured to compress to accommodate a single cable having a plurality of diameters. For example, the inner sleeve(s) 110 may be disposed around a portion of a cable having a plurality of layers, at least some of the layers having different diameters. In some embodiments, the inner sleeve(s) may have a working range that is value between about 1 mm to about 5 mm, inclusive of all ranges and subranges therebetween. That is, the inner sleeve(s) may be configured to compress to a predetermined diameter plus or minus the working range (e.g., 10 mm + / - 3 mm). In some embodiments, increasing the number of slots 118, increasing the width of the slots 118, and / or decreasing a space between the slots may increase the deformability of the inner sleeve(s) 110.

[0039] In some embodiments, the terminal 100 may include a pair of outer sleeves 120 including a first outer sleeve configured to be disposed around the first end portion of the inner sleeve 110 and a second outer sleeve configured to be disposed around the second end portion of the inner sleeve 110. In some embodiments, the outer sleeve(s) 120 may include an inner surface corresponding to a shape of the inner sleeve(s) 110. For example, the inner surface of the outer sleeve(s) 120 may taper according to a taper angle of the inner sleeve(s) 110. For example, the inner surface of the first outer sleeve may taper according to the tapering of the first end portion and the inner surface of the second outer sleeve may taper according to the tapering of the second end portion.

[0040] In some embodiments, an outer surface of the outer sleeve(s) 120 may include at least one mating feature(s) 130. In some embodiments, the outer surface of the outer sleeve(s) 120 may form any suitable shape such as, for example, a triangle, a square, a pentagon, a hexagon, an octagon, etc. In some embodiments, the outer sleeve(s) 120 may include a hexhaving an inner surface with a circular cross-section and a hexagonal outer surface. In some embodiments, the outer sleeve(s) 120 may include a plurality of mating features 130 disposed on at least a portion of an outer surface of the outer sleeve(s) 120. In some embodiments, the outer sleeve(s) 120 may include a plurality of mating features 130 with one or more mating features 130 disposed on each flat portion of the outer surface. In some embodiments, the mating features 130 may extend from an outer surface through an inner surface of the outer sleeve(s) 120. In some embodiments, one or more mating features 130 can be electrically isolated from one another and each of the one or more mating features 130 may be electrically coupled to a corresponding electrical phase of the conductive elongate member 150. In this way, each phase of the conductive elongate member 150 can be terminated, allowing current to be injected into and / or withdrawn from each electrically isolated layer of the conductive elongate member 150. In some embodiments, each electrical phase of the conductive elongate member 150 may be configured to receive a separate contact terminal, and each contact terminal may be isolated from each of the other contact terminals (e g., the contact terminals may be configured such that they do not physically touch one another). Voltage isolation between the contact terminals of different electrical phases can be maintained by including dielectric insulation or isolation “spacers” in between adjacent contact terminals. In some embodiments, the mating features 130 may be configured to couple to a current source and / or current sink (e.g., any component configured to withdraw and / or inject current) such that the current source and / or cunent sink contacts the outer surface of the outer sleeve(s) 120 to conduct current between the contact terminal and the current source and / or current sink. In some embodiments, the mating features 130 may be any suitable connector such as a bolt, screw-, threaded opening, etc. to fasten the component configured to withdraw and / or inject current to the outer surface of the outer sleeve(s) 120.

[0041] In some embodiments, the outer sleeve(s) 120 may be coupleable to one another via one or more connectors. The outer sleeve(s) 120 may define one or more openings extending therethrough and configured to receive a portion of a connector. In some embodiments, the one or more openings may extend along a length of the outer sleeve(s) 120. In some embodiments, when the outer sleeve(s) 120 are a hex, an opening may be defined near each comer of the hex. In some embodiments, an elongate member such as a screw, bolt, threaded rod, or bar may be disposed through the openings (or a subset of the openings) and fastened to the outer sleeve(s) 120 via one or more fasteners. In some embodiments, each of the outer sleeve(s) 120 may be fastened at a position along a length of the same connector(s) and fixed relative to one another.For example, the connector(s) may maintain the first outer sleeve and the second outer sleeve at a fixed distance from one another.[O042| In some embodiments, when the outer sleeve(s) 120 are disposed around the inner sleeve(s) 110 and coupled to one another (e.g., via the connectors), the terminal 100 may be in the clamped configuration. Axial / clamping forces applied to the outer sleeve(s) 120 via the connectors can urge the outer sleeve(s) 120 up the tapered end portion(s) of the inner sleeve(s) 110, causing the inner sleeve(s) to deform inward, imparting a radial clamping force on the conductive elongate member 150. In some embodiments, the terminal 100 in the clamping configuration may be configured to apply a clamping pressure in a predetermined range. For example, the clamping pressure can be proportional to a torque used to tighten the connectors. In some embodiments, the predetermined range of clamping pressure may be between about 10 megapascals (MPa) and about 60 MPa, inclusive of all ranges and subranges therebetween. In some embodiments, the clamping pressure may be below 30 MPa to prevent damage and / or degradation of a superconducting cable, for example. In some embodiments, the terminal 100 may be configured to apply a substantially uniform (e.g., within 5%) clamping pressure (e.g., contact force, compression force, etc.) to the conductive elongate member 150. In some embodiments, the clamping pressure may be substantially uniform radially about the conductive elongate member 150 (e.g., around a circumference of the conductive elongate member 150). In some embodiments, the clamping pressure may be substantially uniform along a length of the portion of the conductive elongate member 150.

[0043] The uniform clamping pressure may improve uniformity of a contact resistance between the conductive elongate member and the contact terminal 100. In some embodiments, the contact resistance may be uniform radially about the conductive elongate member 160 and along a length of the portion of the conductive elongate member 150. In some embodiments, when the contact terminal 100 is coupled to the conductive elongate member 150, a contact resistance between the conductive elongate member and the apparatus is between about 200nQ and about 20p . inclusive of all ranges and subranges therebetween. In some embodiments, the contact resistance may be configured to be below a predetermined threshold, which can keep ohmic heating associated with current flowing between the conductive elongate member 150 and the inner sleeve 110 below a predetermined threshold. In some embodiments, the contact resistance may be below about 200n .[0044| In some embodiments, a fill material may be disposed between the inner sleeve 110 and an outer surface of the conductive elongate member 150. The fill material may be disposedaround the conductive elongate memberl50 in a solid state. For example, the fill material may be in sheets or foils. In some embodiments, the sheets or foils of the fill material may be disposed around the conductive elongate member 150 in one or more layers. In some embodiments, the sheets or foil may be soft or pliable such that the fill material can fill gaps or voids between the conductive elongate member and the inner surface of the inner sleeve 110 when the inner sleeve 110 applies the clamping pressure to the portion of the conductive elongate member 150 without heat being applied to the system. The fill material being in a solid state may reduce complexity of installation of the terminal and improve repeatability of installation. In some embodiments, the fill material may be any suitable fill material such as, for example, indium, tin, copper, silver, bismuth, zinc, antimony, or a suitable combination thereof.

[0045] In some embodiments, the conductive elongate member 150 may include a plurality of layers each having a respective outer diameter. Therefore, the terminal 100 may include one or more inner sleeve(s) 110 having different inner diameters and / or deformability such that the terminal 100 can apply a uniform clamping pressure to a cable having different outer diameters along its length (e.g., a cable having different and / or electrically isolated layers of superconducting bands). In some embodiments, the inner sleeve(s) 110 may include a first tapered portion and a second tapered portion. In some embodiments, a wide end of the first tapered portion may abut a narrow end of the second tapered portion. In some embodiments, the first tapered portion and the second tapered portion may have different inner diameters and / or different deformability such that they accommodate different (e.g.. electrically isolated) layers of the conductive elongate member 150. In some embodiments, a first outer sleeve 120 may be configured to be disposed around the first tapered portion and a second outer sleeve 120 may be configured to be disposed around the second tapered portion. The first tapered portion may may define a plurality of slots such that, when the first outer sleeve is disposed around the first tapered portion, the first tapered portion deforms to distributes a clamping pressure to a first portion of the conductive elongate member. The second tapered portion may define a plurality of slots such that, when the second outer sleeve is disposed around the second tapered portion, the second tapered portion deforms to distributes a clamping pressure to a second portion of the conductive elongate member. In some embodiments, an end cap may be disposed at a terminal end of the conductive elongate member 150. In some embodiments, the wide end of the first tapered portion may abut the end cap 170.[0046| The end cap 170 may include an inner diameter corresponding to an inner diameter of the conductive elongate member 150. An outer surface of the end cap 170 may be any suitable shape such as a triangle, square, rectangle, pentagon, hexagon, etc. In some embodiments, the end cap may have an outer surface forming a square. In some embodiments, the end cap may define a one or more openings configured to align with the one or more openings of each outer sleeve 120 such that the end cap 170 can be coupled to the outer sleeve(s) 120 via the connectors.[0047J The terminal 100 may include a conductive material such that cunent can be injected and / or withdrawn from the conductive elongate member 150. For example, the inner sleeve(s) 110, the outer sleeve(s) 120, and / or the mating feature(s) 130 may include the conductive material. The conductive material may be any suitable conductive material such as, for example, copper, aluminum, silver, gold, etc. or a suitable combination thereof. Typically, the terminal 100 is operable to electrically couple the superconducting elongate member 150 to non-superconductors, so typically the terminal 100 is constructed of non-superconducting materials, but terminals conducted partially or entirely of superconducting materials are also possible.[0048| FIG. 2 is a schematic block diagram of a terminal 200 (e.g., a contact terminal) for a conductive elongate member, according to embodiments. As shown, the contact terminal 200 may include an inner sleeve including a first end 212, a second end 214, and a central portion 216 extending between the first end 212 and the second end 214. The first end 212 and the second end 214 of the inner sleeve 210 may be tapered. For example, the inner sleeve 210 may have a cylindrical inner diameter configured to be positioned over a cylindrical conductive elongate member 150 and the outer diameters of the first end 212 and the second end 214 may each taper from the central portion 216 to a terminal end of each of the first end 212 and the second end 214, as described in further detail with respect to FIGS. 3-6C. The inner sleeve can be configured to be disposed around conductive elongate member (not shown in FIG. 2).

[0049] A first outer sleeve 222 may be configured to be disposed around the first end 212 and a second outer sleeve 224 may be configured to be disposed around the second end 214. In some embodiments, the first outer sleeve 222 and the second outer sleeve 224 may include an inner surface corresponding to a shape of the first end 212 and the second end 214, respectively, of the inner sleeve 210. For example, the inner surfaces of the first outer sleeve 222 and the second outer sleeve 224 may taper according to a taper angle of first end 212 and the second end 214, respectively, of the inner sleeve 210. The first outer sleeve 222 and thesecond outer sleeve 224 may each include mating feature(s) 230 on an outer surface thereof configured to couple to an external device (e.g., a current source / sink).[0050| The inner sleeve may include one or more slot(s) 218 extending longitudinally along a portion of the inner sleeve. The slot(s) 218 may allow first end 212 to deform when the first outer sleeve 222 is disposed therearound and the second end 214 of the inner sleeve to deform when the second outer sleeve 224 is disposed therearound. A deformability of the first end 212 and the second end 214 may be determined by one or more features of the slot(s) 218. For example, the dimensions of the slot(s) 218 (e.g., length, width) and / or a spacing between adjacent slots may be adjusted to achieve a specific deformability', and therefore, a specific clamping pressure. The terminal 200 may be structurally and / or functionally similar to the terminal 100, and therefore, certain aspects of the terminal 200 are not described herein with respect to FIG. 2.

[0051] In some embodiments, one or more connectors 240 may connect the first outer sleeve 222 to the second outer sleeve 224. A first portion of the connector(s) 240 may extend through the first outer sleeve 222 and a second portion of the connector(s) 240 may extend through the second outer sleeve 224. The connector(s) 240 fasten the first outer sleeve 222 to the second outer sleeve 224 and impart an inward force urging the first outer sleeve 222 towards the second outer sleeve 224 and 120 up the tapered first end portion 212 and the tapered second end portion 214 of the of the inner sleeve 210, causing the inner sleeve(s) to deform inward, imparting a radial clamping force on a conductive elongate member disposed within the inner sleeve 210.

[0052] FIG. 3 is an illustration of a side view of an inner sleeve 310 of a terminal (e.g., a contact terminal) including a first end portion 312, a second end portion 314, and a central portion 316 extending therebetween, according to embodiments. As shown, the first end portion 312 has a first length LI, the second end portion 314 has a second length L2, and the central portion 316 has a third length L3. As shown, the first length LI and the second length L2 may be equivalent. The first length LI and the second length L2 may each be longer than the third length L3. In some embodiments, LI and L2 may not be equivalent. In some embodiments, the third length L3 may be longer than the first length LI and / or the second length L2. In some embodiments, the first length LI, the second length L2, and the third length L3 may be equivalent. In some embodiments, a ratio of the third length L3 to the first length LI (or second length L2) may be in a range between about 0 and about 1.0, inclusive of all ranges and subranges therebetween.[0053J The first end portion 312 and the second end portion 314 may each taper from a first diameter to a second diameter smaller than the first diameter with a taper angle A. In some embodiments, the taper angle A may be in a range between about 2 degrees and about 25 degrees, inclusive of all ranges and subranges therebetween. In some embodiments, the taper angle of the first end portion 312 may be different than the taper angle of the second end portion 314.

[0054] The inner sleeve 310 may define a plurality of slots. The slots may extend along a portion of the inner sleeve 310. In some embodiments, the inner sleeve 310 may include a first set of slots 318a and a second set of slots 318b. As shown, the first set of slots 318a may begin at a terminal end of the first end portion 312 of the inner sleeve 310 and the second set of slots 318b may begin at a terminal end of the second end portion 314 of the inner sleeve 310. The first set of slots 318a and the second set of slots 318b may have a total length shorter than a total length (L I + L2 + L3) of the inner sleeve 310. In some embodiments, a total length of the slots 318a, 318b may be about 75% to about 90% of the total length of the inner sleeve 310, inclusive of all ranges and subranges therebetween. In some embodiments, one or more parameters of the slots 318a, 318b may be adjusted to control a compressive force imparted on the conductive elongate member by the inner sleeve 310 and / or a pliability of the inner sleeve. In some embodiments, the parameters of the slots 318, 318b may include a width W of the slots and / or a number of slots around the inner sleeve 310. In some embodiments, increasing the width W and / or number of slots may increase a pliability of the inner sleeve 310 such that the sleeve can deform a wider range of diameters and / or such that less compressive force from the outer sleeve 320 compresses the inner sleeve 310. In some embodiments, a thickness of the material of the inner sleeve 310 (e.g., a distance from an inner diameter to an outer surface of the inner sleeve 310) may control the pliability and / or compressive force the inner sleeve 310 imparts on the conductive elongate member. In some embodiments, increasing the thickness of the inner sleeve 310 may reduce the pliability of the inner sleeve 310 such that a larger compressive force from the outer sleeve 320 causes the inner sleeve 310 to deform.

[0055] The inner sleeve 310 may be structurally and / or functionally similar to the inner sleeves 110, 210, and therefore, certain aspects of the inner sleeve 310 are not described herein with respect to FIG. 3. Further details regarding the dimension of the inner sleeve are described below in FIGS. 5-6C.[0056| FIGS. 4A-4C show schematic diagrams of a terminal 400 (e.g., a contact terminal) configured to apply substantially uniform clamping pressure to a conductive elongate member450, according to an embodiment. As shown in FIG. 4A, the contact terminal 400 includes an inner sleeve 410 including a first end portion 412, a second end portion 414, and a central portion 416. The inner sleeve 410 may be configured to be disposed around the conductive elongate member 450 such that the conductive elongate member 450 extends longitudinally through the inner sleeve 410. The inner sleeve 410 may further include one or more slots extending longitudinally along the inner sleeve 410 and spaced circumferentially around the inner sleeve. The slots 418a, 418b may extend along a length shorter than a total length of the inner sleeve 410. The terminal 400 further includes a first outer sleeve 422 disposed around the first end portion 412 and a second outer sleeve disposed around the second end portion 414 such that the central portion 416 is exposed. As discussed in further detail herein, an inward axial force applied between the first outer sleeve 422 and the second outer sleeve 424 can cause the inner sleeve 410 to deform and a force or clamping pressure to be applied on the conductive elongate member 450 that acts radially inward.

[0057] As shown in FIG. 4B, the conductive elongate member 450 includes a former 452 and a superconducting portion 451 (e.g., superconducting bands) disposed around the former 452. The inner sleeve 410 is configured to contact an outer surface of the superconducting portion 451 of the conductive elongate member 450 and apply a radial clamping pressure sufficient to form good electrical contact, yet insufficient to damage and / or crack of the typically brittle superconducting portion 451. As shown, the clamping pressure applied by the inner sleeve 410 radially inward is substantially uniform and / or distributed across the surface of the superconducting portion 451. As shown in FIG. 4C, the contact terminal 400 may be configured to apply a clamping pressure along a length of the portion of the conductive elongate member 450 disposed within the inner sleeve 410 that is substantially uniform.|0058| Although not shown, a fill material may be disposed between an outer surface of the superconducting portion 451 and an inner surface of the inner sleeve 410 to increase contact between the inner sleeve 410 and the conductive portion 451. The fill material may be disposed around the superconducting portion 451 in a solid state prior to the inner sleeve 410 being disposed around the superconducting portion 451. Therefore, when the inner sleeve 410 is disposed around the super conductive portion, the fill material may fill space betw een uneven surfaces to reduce the contact resistance between the conductive elongate member 450 and the terminal 400.[0059| FIG. 5 is a perspective view of an inner sleeve 510 of a terminal (e.g., a contact terminal) configured to couple to a conductive elongate member, according to an embodiment.As shown, the inner sleeve 510 includes a first end portion 512, a second end portion 514, and a central portion 516 extending between the first end portion 512 and the second end portion 514. The inner sleeve 510 defines an inner volume such that the conductive elongate member can extend longitudinally therethrough. The central portion 516 may have a first diameter. The first and second end portions 512, 514 may be configured to taper from the first diameter to a second diameter smaller than the first diameter. In some embodiments, the first and second end portions 512, 514 may taper at a predetermined taper angle.

[0060] The inner sleeve 510 may include a plurality of slots 518a, 518b (e.g., openings, holes, cut outs, etc.) defined in a surface thereof. As shown, the inner sleeve 510 includes a first set of slots 518a extending from a terminal end of the first end portion 512 and terminating at a point along the second end portion 514. The inner sleeve 510 further includes a second set of slots 518b extending from a terminal end of the second end portion 512 and terminating at a point along the first end portion 512. The first set of slots 518a and the second set of slots 518b may alternate around a circumference of the inner sleeve 510, as shown. In some embodiments, a width of the slots 518a, 518b, a number of slots 518a, 518b, a distance between adjacent slots, and / or a taper angle of the first and second end portions 512, 514 may be configured to allow the inner sleeve 510 to deform to a predetermined range of diameters corresponding to a diameter of the conductive elongate member 550 to be disposed therein. In some embodiments, the slots 518a, 518b and the taper angle may allow the inner sleeve 510 to accommodate to a plurality of cable diameters while applying a clamping pressure within a predetermined range. The inner sleeve 510 may be structurally and / or functionally similar to the inner sleeves 110, 210, 410, 510, and therefore, certain details of the inner sleeve 510 is not described herein with respect to FIG. 5.[00611 FIGS. 6A shows a side view of the inner sleeve 510 of FIG. 5. FIG. 6B show a cross-sectional view of the inner sleeve 510 along the section A-A, according to embodiments. The first end portion 512 may have a first length LI, the second end portion 514 may have a second length L2, and the central portion may have a third length L3. In some embodiments, the first length LI and the second length L2 may be equivalent. In some embodiments, the first length LI and the second length L2 may be in a range of about 0.5 inch (in) to about 3 inches, inclusive of all ranges and subranges therebetween. In some embodiments, the first length LI and the second length L2 may be in a range of about 1 inch to about 2 inches, inclusive of all ranges and subranges therebetween. In some embodiments, the length L3 may be in a range of about 0.25 inch to about 1 inch, inclusive of all ranges and subranges therebetween. In someembodiments, a total length of the inner sleeve 510 may be in a range of about 2 inches to about 6 inches, inclusive of all ranges and subranges therebetween.[O062| In some embodiments, the first set of slots 518a may terminate a distance Wt from the second end between about 0.25 in and about 0.75 in or between about 0.30 in to about 0.50 in, inclusive of all ranges and subranges therebetween. In some embodiments, the second set of slots 318b may terminate a distance Wt from the first end between about 0.25 in and about 0.75 in or between about 0.30 in to about 0.50 in, inclusive of all ranges and subranges therebetween. In some embodiments, the width Ws of each slot 518a, 518b may be in a range between about 0.05 in and about 0.20 in, inclusive of all ranges and subranges therebetween. The slots 518a, 518b may terminate with a rounded end. In some embodiments, a radius Rs of the rounded terminal end of each of the slots 518a, 518b may be in a range between about 0.025 in and about 0.075 in, inclusive of all ranges and subranges therebetween. In some embodiments, the width Ws, the distance W between adjacent slots, the taper angle, and / or the number of slots 518a, 518b may be configured to allow a predetermined deformability of the inner sleeve 510.[0063| As shown in FIG. 6B, an inner diameter ID of the inner sleeve 510 is constant throughout a length of the inner sleeve 510, while an outer diameter of the inner sleeve 510 tapers from a first outer diameter OD1 in a central portion 516 to a second outer diameter OD2 at the terminal ends of the first end portion 512 and the second end portion 514 of the inner sleeve 510.

[0064] FIG. 7 is a front view of the inner sleeve 510 of the terminal, according to embodiments. The inner sleeve 510 (e.g., the first end portion 512, the central portion 516, and the second end portion (not shown)) has an inner diameter ID. In some embodiments, the inner diameter ID may correspond to a diameter to a conductive elongate member configured to be disposed therein. The inner diameter ID may be in a range between about 0.5 in to about 2 in, inclusive of all ranges and subranges therebetween. In some embodiments, the inner diameter ID may be in a range between about 1 in to about 1.5 in, inclusive of all ranges and subranges therebetween. The central portion 516 has a first outer diameter OD1. The first outer diameter OD1 may be in a range between about 1.5 into about 3 in, inclusive of all ranges and subranges therebetween. In some embodiments, the first outer diameter OD 1 may be in a range between about 1.8 in to about 2.3 in, inclusive of all ranges and subranges therebetween. The first end portion 512 and the second end portion (not show n in FIG. 7) may taper from the first outer diameter GDI to a second outer diameter OD2 smaller than the first outer diameter OD1. Thesecond outer diameter OD2 may be in a range between about 1 in to about 2.5 in, inclusive of all ranges and subranges therebetween. In some embodiments, the second outer diameter OD2 may be in a range between about 1.3 in to about 1.9 in, inclusive of all ranges and subranges therebetween.

[0065] In some embodiments, each slot may be separated by a central angle B. As shown, central angle B is a central angle of the circle defined by outer diameter OD1. The central angle B can have an apex at a longitudinal axis LA of the inner sleeve 510, a first leg intersecting a center point of a first slot (e.g., slot 518a), and a second leg that intersects a center point of a second slot (e.g., slot 518b). The central angle B may be in a range between about 15 degrees and about 120 degrees, inclusive of all ranges and subranges therebetween. In some embodiments, the central angle B may be about 30 degrees, inclusive of all ranges and subranges therebetween. The slots 518a, 518b may extend from the inner surface of the inner sleeve 510 to an outer surface of the inner sleeve 510.

[0066] FIG. 8 shows a perspective view of an outer sleeve 620 of a terminal (e.g.. a contact terminal), according to an embodiment. As shown, the outer sleeve 620 defines an inner volume 625 through which a portion of an inner sleeve (e.g., inner sleeve 510 discussed above and shown in FIGS. 5-7) may be disposed. An inner surface of the outer sleeve 620 includes a circular cross-section with a diameter of the circular cross-section varying along a length of the outer sleeve 620. An outer surface of the outer sleeve 620 forms a hexagonal shape. In some embodiments, a pair of mating features 630a, 630b may be disposed on each flat portion 626 of the hexagonal outer surface. In some embodiments, the outer sleeve 620 may define a plurality of openings 632 that extend through an entire length of the outer sleeve 620 (e.g., from a first end of the outer sleeve 620 to a second end of the outer sleeve 620 opposite the first end). In some embodiments, each opening 632 of the plurality of openings may define a cylindrical inner volume configured to receive a connector. In some embodiments, an opening 632 may be disposed between the inner surface and a comer of the hexagonal outer surface. While the mating features 630a, 630b and openings 632 are shown as cylindrical, it should be appreciated that any the outer sleeve 620 may include any shaped features suitable for coupling to external components. Connectors may be configured to be disposed through each opening 632 (or a set of openings 632). In some embodiments, the outer sleeve 620 can be slid along the connector until the inner diameter of the outer sleeve 620 contacts the outer diameter of the inner sleeve. The outer sleeve 620 may be structurally and / or functionally similar to the outersleeves 120, 220, 420, and therefore, certain details of the outer sleeve 620 is not described herein with respect to FIG. 8.[0067| FIGS. 9A-9C show a front view, a cross-sectional side view, and a top view, respectively, of the outer sleeve of the terminal 600 of FIG. 8, according to embodiments. As shown in FIG. 9 A, a height OD3 of the outer sleeve 620 (e.g., a distance between an outer surface of opposite flat portions 626) may be between about 0.25 in and about 10 in, inclusive of all ranges and subranges therebetween.

[0068] FIG. 9B is a cross-sectional view of the outer sleeve 620 in FIG. 9A taken along the axis A-A. As shown in FIG. 9B, the outer sleeve 620 has a first inner diameter ID2 that tapers from the first end of the outer sleeve 620 to a second inner diameter ID3 at the second end of the outer sleeve 620. The first inner diameter ID2 may correspond to or be based on a first outer diameter OD1 of the inner sleeve. The second inner diameter ID3 may correspond to or be based on a second outer diameter OD2 of the inner sleeve. In some embodiments, first inner diameter ID2 may be smaller (e.g., some predetermined amount smaller) than the first outer diameter GDI of the inner sleeve, and the second inner diameter ID may be larger (e.g., some determined amount larger) than the second outer diameter OD2 of the inner sleeve. Therefore, the outer sleeve 620 may be positioned between the endpoints of the taper of the inner sleeve. The taper angle from the first inner diameter ID2 to the second inner diameter ID3 may correspond to the taper angle of the first and second end portions of the inner sleeve. The tapered inner diameter of the outer sleeve 620 may allow the outer sleeve 620 to fit around an end portion of the inner sleeve 610.

[0069] As shown in FIG. 9C, each flat portion 626 may have a width 627 and a length 628 (e.g., equivalent to the total length of the outer sleeve 620). In some embodiments, each flat portion 626 may have a width 627 in a range between about 0.125 in to about 5 in, inclusive of all ranges and subranges therebetween. In some embodiments, each flat portion 626 may have a length 628 in a range between about 1.25 in and about 5 in inclusive of all ranges and subranges therebetween. In some embodiments, the width 627 may be smaller than the length 628.

[0070] In some embodiments, the first mating feature 630a may be a distance 629 from the first end of the outer sleeve 620. The second mating feature 630a may be located the same distance 629 from the second end of the outer sleeve 620. The mating features 630 may include a threaded hole of any suitable dimension.[00711 FIG. 10 shows a contact terminal 700 disposed around a terminal end of a superconducting cable 750, according to an embodiment. As shown, a first outer sleeve 722 is disposed around a first end portion of the inner sleeve 710 and a second outer sleeve 724 is disposed around a second end portion of the inner sleeve 710 such that a central portion 716 of the inner sleeve 710 is exposed. The inner sleeve 710 includes a plurality of slots 718 extending longitudinally along the inner sleeve and spaced circumferentially around the inner sleeve 710. The central portion 716 of the inner sleeve 710 is substantially cylindrical. The first outer sleeve 722 and the second outer sleeve 724 each include a hexagonal outer surface. Each flat portion of the outer surface includes a pair of mating features 730a, 730b configured to be coupled to an external component (e.g., a current sink / current source). In some embodiments, the mating features 730a, 730b may be a threaded cavity. The first outer sleeve 722 and the second outer sleeve 724 may be coupled to one another via a connector assembly including one or more connectors 742 and one or more fasteners 744. The first outer sleeve 722 and the second outer sleeve 724 may each define one or more openings extending therethrough. The connectors 742 may be elongate members (e.g., a bolt, a rod, threaded rod, a screw, etc.) configured to extend through an opening of the first outer sleeve 722 and through a corresponding opening in the second outer sleeve 724. In some embodiments, a plurality of connectors 742 may be used. Two connectors 742 are used to couple the first outer sleeve 722 and the second outer sleeve 724 are visible in FIG. 10. As shown in FIG. 10, the connectors 742 may couple the first outer sleeve 722 to the second outer sleeve 724 using nuts 744.

[0072] The connectors 742 may maintain a position of the first outer sleeve 722 and the second outer sleeve 724 relative to the inner sleeve 710. For example, axial / clamping forces applied to the outer sleeves 722, 724 via the connectors 742 can urge the outer sleeves 722, 724 up the tapered end portion of the inner sleeve 710, causing the inner sleeve 710 to deform inward, imparting a radial clamping force on the conductive elongate member. In some embodiments, the terminal 700 in a clamping configuration may be configured to apply a clamping pressure in a predetermined range. For example, the clamping pressure can be proportional to a torque used to tighten the connectors 724. In some embodiments, the tension on the connectors 724 may maintain a uniform contact pressure on the conductive elongate member. It should be appreciated that any suitable connectors 742 may be used to urge the outer sleeves 722, 724 up the tapered portion of the inner sleeve 710. For example, the openings in the outer sleeves 722, 742 may be threaded such that when the connectors 742 are disposed therethrough, the connectors 742 can be rotated to urge the outer sleeves 722, 742 up thetapered end portion. In some embodiments, any suitable clamping fasteners may be included to urge the outer sleeves 722, 742 up the tapered portions and toward the central portion of the inner sleeve 710.[0073J As shown, the contact terminal (e.g.. the inner sleeve 710 and the pair of outer sleeves 722, 724) include copper such that current can be injected into and / or withdrawn from the superconducting cable by coupling a component configured to inject or withdraw current to the mating features 730a, 730b such the component contacts (e.g., and therefore electrically connects) to flat portions of the outer sleeves 722. 742.[0074| FIG. 11 is a schematic diagram of a terminal 800 including a plurality of inner sleeve portions 810 coupled to an end cap 870, according to an embodiment. As shown, each inner sleeve portion 810 (e.g., “a half collet”) may form a taper from a first diameter (e.g., a wide end) to a second diameter (e.g., a narrow end). The wide end of an inner sleeve portion 810 may be configured to abut a narrow end of an adjacent inner sleeve portion 810. The end cap 870 may be configured to abut a wide end of one of the inner sleeve portions 810. Each inner sleeve portion 810 may have a specific diameter corresponding to the diameter of a layer of a conductive elongate member. For example, each inner sleeve portion 810 may be configured to be disposed around a respective layer of the conductive elongate member, and therefore, each inner sleeve portion 810.[0075J Each inner sleeve portion 810 may be configured to be compressed by a respective outer sleeve such that a uniform radial force is applied along a total length of each inner sleeve portion 810. The terminal 800 allows for tolerances in the cable diameters, providing flexibility in the terminal fit and ensuring a consistent pressure and contact resistance on each layer of the conductive elongate member. In some embodiments, fill material may be disposed (e.g., in a solid state) around the conductive elongate member and configured to fill spaces or voids between an outer surface of the conductive elongate member and an inner surface of each inner sleeve portion 810.

[0076] FIG. 12 is a perspective view- of a terminal 900 including a plurality of inner sleeve portions 910 coupled to an end cap 970 and a plurality of outer sleeve portions 920, according to an embodiment. The plurality of inner sleeve portions 910 and the end cap 970 may define an inner volume through which a conductive elongate member may be disposed. A diameter of the inner volume may vary along a length of the terminal 900. For example, each inner sleeve portion 910 may have a specific inner diameter corresponding to a respective layer ofthe conductive elongate member. As shown, outer sleeves 920 may be disposed around each inner sleeve portion 910. As shown, each inner sleeve potion 910 defines a plurality of slots extending longitudinally therethrough and positioned circumferentially around the inner sleeve portion 910. When each outer sleeve 920 is disposed around a respective inner sleeve portion 910, the inner sleeve 910 may apply a predetermined clamping pressure to the elongate conductive member. For example, each outer sleeve 920 may be urged against the wider outer diameter of a respective inner sleeve portion 810, thereby causing the inner sleeve portion 810 to deform to apply the radial clamping pressure. Certain details of the inner sleeve portions 910 and the outer sleeve portions 920 may be structurally and / or functionally similar to the inner sleeves 110, 210, 310, 410, 510 and outer sleeves 120, 220, 420, 620, and therefore certain details are not described herein with respect to FIG. 12.

[0077] FIG. 13 shows a perspective view of an outer sleeve 1120 of a terminal (e.g., a contact terminal), according to an embodiment. As shown, the outer sleeve 1120 defines an inner volume 1125 through which a portion of an inner sleeve (e.g., inner sleeve 510 discussed above and show n in FIGS. 5-7) may be disposed. An inner surface of the outer sleeve 1120 includes a circular cross-section with a diameter of the circular cross-section varying along a length of the outer sleeve 1120. An outer surface of the outer sleeve 1120 includes a cylindrical shape with a flat portion 1126 disposed along one side of the outer surface. In some embodiments, the outer sleeve 1120 may include two flat portions disposed on opposite sides of the cylindrical outer surface. In some embodiments, flat surface 1126 may serve as an antirotation feature and / or mounting interface. The flat surface 1126 can be configured to engage tools and / or fixtures that prevent rotation during installation or operation, or to support the attachment of external components such as current sources, sensors, structural supports, and / or the like. For example, the flat surface 1126 may be configured to engage with a keyed fixture or torque-limiting tool to prevent rotation of the outer sleeve 1120. In some embodiments, the flat surface may provide a planar reference for alignment or indexing during automated assembly processes.

[0078] In some embodiments, a pair of mating features 1139a, 1139b may be disposed on the flat portion 1126 of the outer surface. In some embodiments, the outer sleeve 1120 may define a plurality' of openings 1132 that extend through an entire length of the outer sleeve 1120 (e.g., from a first end of the outer sleeve 1120 to a second end of the outer sleeve 1120 opposite the first end). In some embodiments, each opening 1132 of the plurality of openings may definea cylindrical inner volume configured to receive a connector. In some embodiments, an opening 1132 may be disposed between the inner surface and a perimeter of the outer surface.[0079| In some embodiments, the plurality of openings 1132 can symmetrically distributed around the end face of the outer sleeve 1120. Without being bound by a theory, the symmetrical distribution of openings may help balance mechanical loads and ensure uniform pressure application during clamping. In some embodiments, the plurality of openings 1132 can be asymmetrically distributed around the end face of the outer sleeve 1120. In some embodiments, at least one of the plurality of openings 1132 can be configured to receive bolts, screws, or other fasteners. These openings may facilitate mechanical coupling of the outer sleeve 1120 to adjacent components such as another sleeve, an end cap, and / or a structural fixture. In some embodiments, the plurality of openings 1132 may be threaded or dimensioned to accommodate torque-controlled fasteners that apply axial force, urging the outer sleeve 1120 up a tapered portion of the inner sleeve to induce radial compression and establish electrical contact. |0080] While the mating features 1139a. 1139b and openings 1132 are shown as cylindrical, it should be appreciated that the outer sleeve 1120 may include any shaped features suitable for coupling to external components. Connectors may be configured to be disposed through each opening 1132 (or a set of openings 1132). In some embodiments, the outer sleeve 1120 can be slid along the connector until the inner diameter of the outer sleeve 1120 contacts the outer diameter of the inner sleeve. In some embodiments, the outer sleeve 1120 may be formed from a conductive material such as copper, aluminum, or a copper alloy, allowing current to be injected into or withdrawn from the conductive elongate member via mating features disposed on or near flat surface 1126. In some embodiments, the outer sleeve 1120 may be configured to accommodate dielectric isolation features, strain relief components, or thermal management structures depending on the application. The outer sleeve 1120 may be structurally and / or functionally similar to the outer sleeves 120, 220, and 420, and therefore, certain details of the outer sleeve 1120 are not described herein with respect to FIG. 13.10081] FIGS. 14A-14C show a front view, a cross-sectional side view, and a top view, respectively, of the outer sleeve 1120 of the terminal of FIG. 13, according to an embodiment.

[0082] As shown in FIG. 14A, a height OD3 of the outer sleeve 1120 (e.g., a distance between the outermost points of the cylindrical body) may be between about 0.25 in and about 10 in, inclusive of all ranges and subranges therebetween. The inner volume 1125 is disposed at the center of the outer sleeve 1120 and may be configured to receive a portion of an innersleeve or a terminal end of a conductive elongate member. The plurality of openings 1132 are symmetrically distributed around the inner volume 1125. In some embodiments, the outer sleeve 1120 may include six openings, evenly spaced around the circumference of the end face, as shown in FIG. 14A. In some embodiments, the number of openings 1132 may vary. For example, the outer sleeve 1120 may include two, three, four, eight, ten, or twelve openings, inclusive of all ranges and subranges therebetween. In some embodiments, the openings 1132 may be asymmetrically distributed to accommodate specific mounting and / or electrical interface requirements. These openings may be configured as through-holes for bolts, screws, or other fasteners to mechanically couple the outer sleeve 1120 to adjacent components such as an end cap or another sleeve (e.g., a second outer sleeve).

[0083] FIG. 14B is a cross-sectional view of the outer sleeve 1120 in FIG. 14A taken along the axis A- A. As shown in FIG. 14A, the outer sleeve 1120 has a first inner diameter ID2 that tapers from the first end of the outer sleeve 1120 to a second inner diameter ID3 at the second end of the outer sleeve 1120. The first inner diameter ID2 may correspond to or be based on a first outer diameter OD1 of the inner sleeve. The second inner diameter ID3 may correspond to or be based on a second outer diameter OD2 of the inner sleeve. In some embodiments, the first inner diameter ID2 may be smaller (e.g., some predetermined amount smaller) than the first outer diameter OD1 of the inner sleeve, and the second inner diameter ID3 may be larger (e.g., some determined amount larger) than the second outer diameter OD2 of the inner sleeve. Therefore, the outer sleeve 1120 may be positioned between the endpoints of the taper of the inner sleeve. The taper angle from the first inner diameter ID2 to the second inner diameter ID3 may correspond to the taper angle of the first and second end portions of the inner sleeve. The tapered inner diameter of the outer sleeve 1120 may allow the outer sleeve 1120 to fit around an end portion of the inner sleeve and apply a uniform radial clamping pressure when axial force is applied.

[0084] In some embodiments, the tapering angle between the first inner diameter ID2 and the second inner diameter ID3 of the outer sleeve 1120 may be selected to obtain desired radial clamping pressure, mechanical engagement, and / or alignment with the tapered portions of the inner sleeve. The tapering angle may be defined as the angular difference between the longitudinal axis of the sleeve and the sloped inner surface transitioning from ID2 to ID3.[00851 In some embodiments, depending on the desired clamping force, sleeve material properties, and / or cable diameter tolerances, the tapering angle may be at least about 1 degree, at least about 2 degrees, at least about 3 degrees, at least about 4 degrees, at least about 5degrees, at least about 6 degrees, at least about 7 degrees, at least about 8 degrees, at least about 9 degrees, at least about 10 degrees, at least about 11 degrees, at least about 12 degrees, at least about 13 degrees, at least about 14 degrees, or at least about 15 degrees, inclusive of all ranges and subranges therebetween. In some embodiments, the tapering angle may be no more than about 45 degrees, no more than about 40 degrees, no more than about 35 degrees, no more than about 30 degrees, no more than about 25 degrees, no more than about 20 degrees, no more than about 15 degrees, no more than about 10 degrees, or no more than about 5 degrees, inclusive of all ranges and subranges therebetween, to prevent excessive deformation or stress on the inner sleeve or the conductive elongate member. In some embodiments, the tapering angle may be about 1 degree, about 2 degrees, about 3 degrees, about 4 degrees, about 5 degrees, about 6 degrees, about 7 degrees, about 8 degrees, about 9 degrees, about 10 degrees, about 11 degrees, about 12 degrees, about 13 degrees, about 14 degrees, about 15 degrees, about 16 degrees, about 17 degrees, about 18 degrees, about 19 degrees, or about 20 degrees, inclusive of all ranges and subranges therebetween.

[0086] The selected tapering angle may correspond to the taper angle of the first and second end portions of the inner sleeve such that, when axial force is applied to the outer sleeve, the inner sleeve deforms inward to apply a substantially uniform radial clamping pressure to the conductive elongate member.

[0087] As shown in FIG. 14C, the outer sleeve 1120 includes the flat surface 1126 disposed along the top side of the cylindrical body. The flat surface 1126 may have a width 1127 and a length 1128 (e.g., equivalent to the total length of the outer sleeve 1120). In some embodiments, the width 1127 may be in a range between about 0.125 in and about 5 in, inclusive of all ranges and subranges therebetween. In some embodiments, the length 1128 may be in a range between about 1.25 in and about 5 in, inclusive of all ranges and subranges therebetween. In some embodiments, the width 1127 may be smaller than the length 1128.

[0088] In some embodiments, the mating features 1130a and 1130b may be located a distance 1129 from the respective ends of the outer sleeve 1120. In some embodiments, the mating features 1130a and 1130b may be located a distance 1129 from the respective ends of the outer sleeve 1120, and may be used to align or secure the sleeve during installation. The distance 1129 of each mating feature 1130a, 1130b fromits respective end may be the same or different, depending on the desired alignment or securing configuration. In some embodiments, the outer sleeve 1120 may include more than two mating features, or only a single matingfeature. The one or more mating features may be disposed through the thickness of the flat surface of the outer sleeve 1120.[0089| In some embodiments, the flat surface 1126 may be configured to engage tools or fixtures that prevent rotation during installation or operation, or to support the attachment of external components such as current sources, sensors, or structural supports.

[0090] In some embodiments, the inner volume 1125 may accommodate interface components that enhance electrical contact, thermal performance, and / or mechanical stability. The cylindrical design of the outer sleeve 1120 may be particularly advantageous in applications requiring compact form factors, rotational symmetry, and / or the like.[0091 | FIG. 15 shows a terminal 2000 (e.g., a contact terminal) configured to be disposed around a terminal end of a conductive elongate member (e.g., a superconducting cable), according to an embodiment. As shown, a first outer sleeve 2122 is disposed around a first end portion of an inner sleeve 2110 (e.g., similar to or substantially same as the inner sleeve 510 discussed above and shown in FIGS. 5-7) and a second outer sleeve 2124 is disposed around a second end portion of the inner sleeve 2110 such that a central portion of the inner sleeve 2110 is exposed. The inner sleeve 2110 includes a plurality of slots 2118 extending longitudinally along the sleeve 2110 and spaced circumferentially around its surface. The central portion of the inner sleeve 2110 is substantially cylindrical.

[0092] The first outer sleeve 2122 and the second outer sleeve 2124 each include a cylindrical outer surface with a flat portion 2126. The flat portion 2126 may be configured to engage tools or fixtures that prevent rotation during installation or operation, or to support the attachment of external components. In some embodiments, the second outer sleeve 2124 is rotated about 60 degrees with respect to the first outer sleeve 2122. In some embodiments, the rotation of the outer sleeves may be implemented to accommodate specific current injection configurations. For example, in some embodiments, one of the outer sleeves 2122, 2124 may be rotated counterclockwise or clockwise such that the flat portions are angularly offset depending on the electrical phase and / or current routing strategy. However, such rotation may be independent of terminal performance and may be implemented solely for system-level integration.

[0093] Each flat portion of the outer sleeves 2122 and 2124 includes a pair of mating features 2130a and 2130b configured to be coupled to an external component (e.g., a current sink / current source). In some embodiments, the mating features 2130a and 2130b may bethreaded cavities or other suitable connectors. In some embodiments, the mating features on each outer sleeve may be aligned or offset relative to one another depending on the desired electrical or mechanical configuration.

[0094] The contact terminal 2000 further includes a connector 2142 extending through the length of the first outer sleeve 2122 and the second outer sleeve 2124. The connector 2142 may be configured to apply an axial force to urge the outer sleeves up the tapered portions of the inner sleeve 2110, thereby inducing radial compression of the inner sleeve and establishing electrical contact with the conductive elongate member. In some embodiments, the connector 2142 may be disposed through openings defined in the outer sleeves 2122 and 2124 and tightened to maintain the clamping configuration.

[0095] The connector 2142 may be secured by a fastener assembly that includes a nut 2144 (or another suitable fastening element) and, optionally, a sealing element (not shown). A second fastener assembly including a nut 2146 (or another suitable fastening element) and a sealing element 2147 (e.g.. O-rings, washers, or other suitable sealing elements) may be disposed at a rear end of the terminal 2000 and may be configured to secure, align, or isolate the terminal relative to adjacent components or mounting structures. In some embodiments, the sealing element may be configured to provide environmental protection and / or mechanical isolation at the interface.

[0096] A pair of mounting elements 2143a and 2143b (e.g., rectangular interface plates or key fasteners) may be disposed in a stacked configuration and aligned with mating features on the outer sleeve 2124. These mounting elements may be configured to facilitate mechanical coupling, alignment, and / or electrical interface with external components. In some embodiments, the mounting elements may define openings that receive fasteners 2132a, 2132b (e.g., bolts or any suitable fasteners) and sealing elements 2131a, 2131b (e.g., O-rings. washers, or other suitable components configured to provide environmental sealing, mechanical isolation, and / or protection of the underlying interface) to secure and isolate the interface.

[0097] In some embodiments, sealing elements 2131aand 2131b may be disposed between the mounting elements and the outer sleeve 2124 to provide environmental sealing, mechanical isolation, or protection of the mating interface. The mounting elements may facilitate electrical or mechanical coupling to external components, such as current injection hardware, structural supports, or system-level fixtures. The stacked configuration of 2143a and 2143b may beselected to accommodate specific spatial or routing requirements, and their placement may be independent of terminal performance.[0098| As shown, the contact terminal (e.g., the inner sleeve 2110 and the pair of outer sleeves 2122, 2124) may include copper or another conductive material such that current can be injected into and / or withdrawn from the conductive elongate member by coupling a component configured to inject or withdraw current to the mating features 2130a, 2130b such that the component contacts (and therefore electrically connects to) the flat portions of the outer sleeves 2122 and 2124.

[0099] FIG. 16 shows a terminal 3000 (e.g.. a contact terminal) configured to be disposed around a terminal end of a superconducting cable 3150, according to an embodiment. As shown, a first outer sleeve 3122 is disposed around a first end portion of an inner sleeve 3110 (e.g., similar to or substantially same as the inner sleeve 510 discussed above and shown in FIGS. 5-7) and a second outer sleeve 3124 is disposed around a second end portion of the inner sleeve 3110 such that a central portion of the inner sleeve is exposed. The inner sleeve 3110 may include one or more slot(s) 3118 extending longitudinally along a portion of the inner sleeve 3110. The outer sleeves 3122 and 3124 are coupled together via a plurality of connectors 3142, extending through openings defined in the outer sleeves 3122, 3124. The connectors 3142 may be fastened using nuts 3144 or other suitable fasteners to apply axial force.

[0100] Each outer sleeve 3122, 3124 includes a cylindrical outer surface with aflat portion 3126. The flat portions 3126 of the first outer sleeve 3122 and the second outer sleeve 3124 each include a pair of mating features 3130a and 3130b configured to be coupled to an external component (e.g., a current sink / current source). As shown, the second outer sleeve 3124 is not rotated relative to the first outer sleeve 3122, such that the mating features 3130a and 3130b on both sleeves are aligned. This alignment may facilitate simplified coupling to external components or fixtures and may be selected based on system-level design preferences. In some embodiments, the mating features 3130a, 3130b may be threaded cavities, posts, or other suitable connectors.

[0101] FIG. 17 shows a front view of an outer sleeve 4120 of a terminal, according to an embodiment. As shown, the outer sleeve 4120 includes a cylindrical body with two flat portions 4126 disposed on opposite sides of the outer surface. The flat portions 4126 may be configured to engage tools or fixtures that prevent rotation during installation or operation, or to supportthe attachment of external components such as current sources, sensors, and / or structural supports.[0102| The outer sleeve 4120 defines an inner volume 4125 configured to receive a portion of an inner sleeve (e.g., similar to or substantially same as the inner sleeve 510 discussed above and shown in FIGS. 5-7). A plurality of openings 4132 are symmetrically distributed around the perimeter of the end face and may be configured to receive fasteners such as bolts or screws. In some embodiments, the openings 4132 may be used to couple the outer sleeve to adjacent components such as another sleeve, an end cap, and / or a mounting fixture. It should be understood that the number, placement, and orientation of the openings 4132 may be modified according to system-level design considerations, including but not limited to mechanical requirements, electrical routing, or a particular configuration intended for current injection. Additional features may be disposed near the flat portions and may serve as mating features or alignment interfaces. Without being bound by theory, the dual flat portion configuration may facilitate anti-rotation functionality and provide planar surfaces for mounting or indexing during automated assembly processes.[0103| FIG. 18 is a schematic block diagram of a terminal 5000 (e.g., a contact terminal) configured to be disposed around a terminal end of a conductive elongate member, according to an embodiment. In some embodiments, the conductive elongate member may include a superconducting cable or other multi-layered conductor. The conductive elongate member may include a first portion 5150a and a second portion 5150b, which in some embodiments may have different numbers of helically wound superconducting layers. For example, in some embodiments, the first portion 5150a may include eight layers while the second portion 5150b may include seven layers. In other embodiments, the first portion 5150a and the second portion 5150b may include the same number of layers. In some embodiments, each portion may independently include 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, or more layers. The difference in layer count between the first portion 5150a and the second portion 5150b may result in a variation in outer diameter, which may be accommodated by the terminal structure to obtain desired uniform clamping pressure and / or electrical contact.

[0104] A connector 5152 is disposed between the first portion 5150a and the second portion 5150b of the conductive elongate member and may be configured to electrically couple the two portions. In some embodiments, the connector 5152 may be implemented as a conductive tape that spans the interface between the two portions 5150a, 5150b. The conductive tape mayinclude a conductive material disposed on an adhesive substrate, which may be pressuresensitive and optionally electrically conductive. The conductive material may be selected to provide low contact resistance and / or mechanical flexibility, and may include copper in some embodiments. In some embodiments, the conductive material may include aluminum, nickel, silver, or other suitable conductors.{0105 In some embodiments, the conductive tape may have a width ranging from about 1 / 16 inch to about 2 inches. In some embodiments, the width of the tape is about 1 / 4 inch. In some embodiments, the width of the tape is about 1 / 2 inch. The selected width may depend on the available bonding surface area, the required current-carrying capacity, and the mechanical constraints of the cable interface.

[0106] In some embodiments, the connector 5152 may be exposed or partially covered depending on the configuration of surrounding layers. In some embodiments, the connector may be disposed at a location where the superconducting tapes are peeled back or terminated, and may serve as a transitional interface for cunent injection or withdrawal. In some embodiments, the connector may be applied in a solid state and may be configured to accommodate thermal contraction and mechanical stress during cryogenic operation. In some embodiments, the connector may be configured to maintain electrical continuity across the interface without the use of solder, heat, or vacuum-based bonding techniques.

[0107] A fill material 5154 is disposed between the outer surface of the conductive elongate members 5150a, 5150b and the inner surface of the inner sleeve 5110. In some embodiments, the first portion 5150a of the conductive elongate member and the second portion 5150b include a plurality' of superconducting bands wrapped helically around a former. In some embodiments, the number of superconducting layers may vary between the first portion and the second portion.[0108| In some embodiments, the fill material 5154 may be configured to conform to the geometry of the conductive elongate members 5150a, 5150b and fill any voids or irregularities between the conductive elongate member and the surrounding terminal components. In some embodiments, the fill material 5154 may be disposed in a solid state and may be applied without the use of heat, solder, or vacuum-based bonding techniques.

[0109] In some embodiment, the fill material 5154 may be formed into a foil or sheet that may be disposed over the portion of the conductive elongate members 5150a, 5150b (e.g., in one or more layers) such that an entirety of the outer surface of the portion of the conductiveelongate member is covered. In some embodiments, the fill material 5154 may be a soft material in a solid state such that the fill material can mold to an irregular shape. In some embodiments, the fill material 5154 may include any suitable material such as for example, indium, tin, copper, silver, bismuth, zinc, antimony, etc.

[0110] In some embodiments, the fill material 5154 includes a first fill material disposed around the first portion 5150a of the conductive elongate member and a second fill material disposed around the second portion 5150b. In some embodiments, the first fill material and the second fill material may be the same. For example, they may be made from the same material. In some embodiments, the first fill material and the second fill material each include indium foil. In some embodiments, one layer of indium foil is disposed over a conductive elongate member having even-numbered superconducting bands (e.g., layers 2, 4, 6, 8), and more than one layer of indium foil is disposed over a conductive elongate member having odd-numbered superconducting bands (e.g., layers 1, 3, 5, 7). In some embodiments, the number of indium layers may vary depending on the number of superconducting bands (e.g., layers) present in the first portion 5150a and the second portion 5150b. In some embodiments, the number of indium layers may be selected based on the geometry and layer count of the conductive elongate member to obtain desired contact pressure distribution and / or electrical continuity. For example, in some embodiments, the first portion 5150a of the conductive elongate member may include eight superconducting bands wrapped helically around a former, and the second portion 5150b of the conductive elongate member may include seven superconducting bands wrapped helically around a former, and the fill material may be configured accordingly to maintain uniform contact pressure and electrical continuity. For example, in such embodiments, one layer of indium foil can be disposed over the first portion 5150a of the conductive elongate member and two layers of indium foil can be disposed over the second portion 5150b of the conductive elongate member.[0H1] In some embodiments, the fill material 5154 may be secured using narrow' strips of copper tape, which may be applied to maintain the position of the foil during assembly. In some embodiments, the fill material may be in the form of a foil, and the foil may be wrapped around the conductive elongate member such that the opposing edges of the foil abut one another without overlapping, and the foil covers the entire circumference of the conductive elongate members 5150a, 5150b. In some embodiments, the fill material 5154 may be configured to overlap and cover at least a portion of the connector 5152. In some embodiments.the fill material 5154 may be configured such that it does not abut or overlap the connector 5152.[0112| In some embodiments, a conductive layer 5156 may be disposed around the fill material 5154. In some embodiments, the conductive layer 5156 may be configured to electrically couple the conductive elongate member to the surrounding terminal structure. In some embodiments, the conductive layer 5156 includes a first conductive layer disposed around the first portion 5150a and a second conductive layer disposed around the second portion 5150b. In some embodiments, the first conductive layer and the second conductive layer each include a conductive tube. In some embodiments, the conductive tube is formed from copper. In some embodiments, the conductive tube may include aluminum, silver, or other suitable conductive materials.

[0113] In some embodiments, the conductive tube is formed by wrapping and shaping a copper sheet into a cylindrical geometry configured to conform to the outer surface of the fill material 5154. In some embodiments, the copper sheet is cut to a predetermined dimension and formed into a tube using a rolling process. In some embodiments, the tube is configured such that, when wrapped around the fill material, a gap between opposing edges of the tube is maintained. In some embodiments, the opposing edges of the tube do not abut one another and the tube does not cover the entire circumference of the conductive elongate members 5150a, 5150b. In some embodiments, the gap between the opposing edges of the tube can be between about 2 mm and about 3 mm. In some embodiments, the gap is such that it falls within a solid portion of the inner sleeve 5110 and is not visible through any grooves or slots defined in the inner sleeve. This configuration may be selected to prevent exposure of the gap to regions of reduced mechanical support and to maintain electrical continuity across the conductive layer. In some embodiments, the conductive tube is secured using narrow strips of copper tape to prevent spring-back and to maintain a circular cross-section.

[0114] In some embodiments, a clearance (e.g., a gap, spacing) may be present between the conductive layer 5156 and the inner surface of the inner sleeve 5110. This clearance may be configured to accommodate deformation of the inner sleeve 5110 during compression and to ensure uniform contact pressure across the conductive elongate members 5150a, 5150b. In some embodiments, the clearance is less than about 1 mm. In some embodiments, the clearance is less than about 0.9 mm, less than about 0.5 mm, less than about 0.25 mm, less than about 0.1 mm, or less than about 0.05 mm. In other embodiments, the clearance is greater than about 1 mm.[0115J In some embodiments, a mechanical support may be disposed between the conductive layer 5156 and the inner sleeve 5110. The support may be configured to maintain concentric alignment between the conductive elongate members 5150a, 5150b and the inner sleeve prior to compression, and may further serve to stabilize the conductive layer during installation.|0H6] In some embodiments, the conductive layer 5156 may be configured to overlap and cover at least a portion of the connector 5152 to ensure continuous electrical contact across the interface between the first portion 5150a and the second portion 5150b.

[0117] A first outer sleeve 5122 is disposed around the first portion 5150a of the conductive elongate member and a second outer sleeve 5124 is disposed around the second portion 5150b. In some embodiments, the first outer sleeve 5122 and the second outer sleeve 5124 are the same as or similar to the outer sleeves described with respect to FIGS. 1-2. In some embodiments, each outer sleeve is configured to apply a radial clamping pressure to the underlying conductive layer 5156 and fill material 5154 by urging the sleeve up a tapered portion of an inner sleeve 5110. In some embodiments, the outer sleeves 5122, 5124 may include a hexagonal outer surface and a tapered inner surface configured to match the geometry of the inner sleeve. In some embodiments, the outer sleeves 5122, 5124 may be similar to or substantially the same as the outer sleeve 620 as described with respect to FIGS. 8, 9A-C. In some embodiments, the outer sleeves 5122, 5124 may be similar to or substantially the same as the outer sleeve 1120 as described with respect to FIGS. 13, 14A-C. In some embodiments, the outer sleeves may include mating features disposed on flat portions of the outer surface to facilitate electrical connection to external components.

[0118] In some embodiments, the inner sleeve 5110 and the first portion 5150a and second portion 5150b of the conductive elongate member are concentric prior to compression by the outer sleeves 5122 and 5124. This concentric alignment may be configured to obtain desired radial clamping pressure distribution (e.g., uniform distribution) and electrical contact across the interface.|0119] FIG. 19 is a cross-sectional view of a terminal 6000 (e.g., a contact terminal) disposed around a terminal end of a conductive elongate member 6150, according to an embodiment. The conductive elongate member 6150 includes a former 6152 and a superconducting portion 6151 (e.g., superconducting bands) helically wound around the former 6152. A fill material 6154 is disposed over the superconducting portion 6151 and may beconfigured to conform to the geometry of the conductive elongate member 6150 and fill any voids between the superconducting portion and surrounding terminal components.[0120| In some embodiments, the fill material 6154 includes indium foil 6153. In some embodiments, the indium foil includes two, three, or more layers of indium disposed concentrically around the superconducting portion 6151. The number of indium layers may vary depending on the number of superconducting layers and the desired contact pressure. In some embodiments, the indium foil is configured to deform under compression and provide low contact resistance between the conductive elongate member 6150 and the surrounding structures (e.g., an inner sleeve 6110).[012I| A conductive layer 6156 is disposed over the fill material 6154. In some embodiments, the conductive layer 6156 includes a copper tube formed from a copper foil or sheet. The copper tube may be shaped to conform to the outer surface of the fill material 6154 and may be secured using narrow strips of tapes (e.g., copper tapes). In some embodiments, the copper tube does not fully encircle the fill material and includes a gap 6157 between opposing edges. In some embodiments, the gap 6157 is between about 2 mm and about 3 mm. In some embodiments, the gap 6157 does not overlap with any of the slots 6118 defined in the inner sleeve 6110 and is positioned such that it falls within a solid portion of the inner sleeve 6110 to avoid exposure through the grooves.[0122 J The inner sleeve 6110 defines an inner volume configured to receive the conductive elongate member 6150 and includes a plurality of slots 6118 extending along its length. The slots may be configured to allow the inner sleeve 6110 to deform under axial compression and apply a substantially uniform radial clamping pressure to the conductive elongate member 6150. An outer sleeve 6120 is disposed around the inner sleeve 6110 and may be configured to urge the inner sleeve inward during assembly.[0123| In some embodiments, a gap “G"’ is present between the conductive layer 6156 and the inner surface of the inner sleeve 6110. This gap may be configured to allow the inner sleeve 6110 to deform inward during compression without directly contacting the conductive layer prior to clamping. In some embodiments, the gap is less than about 1 mm. In some embodiments, the clearance is about 0.9 mm, about 0.5 mm, about 0.25 mm, about 0.1 mm, or less. In other embodiments, the clearance may be greater than about 1 millimeter, greater than about 1.25 millimeters, greater than about 1.5 millimeters, greater than about 5 millimeters, or greater.[0124J ] In some embodiments, a mechanical support (not shown) may be disposed between the conductive layer 6156 and the inner sleeve 6110. The support may be configured to maintain concentric alignment between the conductive elongate member 6150 and the inner sleeve 6110 prior to compression. In some embodiments, the conductive elongate member 6150 and the inner sleeve 6110 are concentric prior to compression by the outer sleeve 6120.

[0125] In some embodiments, one or more components of terminal 6000 such as the inner sleeve 6110, outer sleeve 6120, fill material 6154, and conductive layer 6156 may be the same as or similar to corresponding components described above with respect to FIGS. 1-2 and FIG.18. In some embodiments, the outer sleeve 6120 may be similar to or substantially the same as the outer sleeves 620 and 1120, as described with respect to FIGS. 8, 9A-9C, and FIGS. 13, 14A-14C.

[0126] FIG. 20A is an illustration of a portion of a terminal, according to an embodiment. A first indium foil 7154a and a second indium foil 7154b are disposed concentrically around a portion of the conductive elongate member (not shown). In some embodiments, the indium foils are configured to conform to the geometry of the underlying superconducting portion and provide low contact resistance. In some embodiments, the indium foil includes two, three, or more layers depending on the number of superconducting layers and the desired contact pressure.

[0127] A first copper tube 7156a is disposed over the first indium foil 7154a, and a second copper tube 7156b is disposed over the second indium foil 7154b. In some embodiments, the copper tubes are formed from copper foil sheets shaped into cylindrical geometries. In some embodiments, the copper tubes are secured using copper tape 7151. In some embodiments, the copper tape is about 1 / 8 inch wide. In other embodiments, the tape width may range from about 1 / 16 inch to about 1 / 4 inch. The copper tape may be configured to prevent spring-back of the copper tube and maintain a circular cross-section during installation.

[0128] A gap 7157 is defined between opposing edges of the copper tube and corresponds to the gap described with respect to FIG. 19. In some embodiments, the gap is between about 2 mm and about 3 mm. In some embodiments, the gap 7157 does not fully cover the surface of the fill material 7154a, 7154b, and is positioned such that it does not overlap with any slots defined in the inner sleeve.

[0129] FIG. 20B is an illustration of a portion of the terminal shown in FIG. 20 A that is disposed within an inner sleeve 7110. As shown, the inner sleeve 7110 at least partiallysurrounds the copper tube 7156a. The inner sleeve 7110 includes a plurality of slots 7117 extending along its length. In some embodiments, the slots are configured to allow the inner sleeve to deform under axial compression. In some embodiments, the gap 7157 is positioned such that it does not overlap with any slot 7117. A mechanical support 7158 is disposed between an inner surface of the inner sleeve 7110 and the copper tube 7156a. In some embodiments, the support 7158 may be configured to maintain concentric alignment between the conductive elongate member and the inner sleeve prior to compression and may further stabilize the conductive layer during installation.[0130| In some embodiments, one or more components shown in FIGS. 20A and 20B, such as the inner sleeve 7110, copper tubes 7156a and 7156b, indium foils 7154a and 7154b, and copper tape 7151, may be the same as or similar to corresponding components described above with respect to FIGS. 1-2, FIG. 18, andFIG. 19. In some embodiments, a portion of the terminal shown in FIGS. 20A and 20B may be coupled with any of the outer sleeves disclosed herein, including those described with respect to FIGS. 1-2, FIGS. 8, 9A-9C, and FIGS. 13, 14A-14C.

[0131] FIG.21 is a flow chart diagram of an example method 10 of coupling a contact terminal (e.g., 100, 200, 700), to a conductive elongate member, according to embodiments. While described with respect to the contact terminal 100 including outer sleeve(s) 220 and inner sleeve(s) 210, the method 10 is equally applicable to any contact terminal including any inner sleeves or outer sleeves described herein. All such variants should be considered to be within the scope of this disclosure.

[0132] The method 10 may include disposing a fdl material around an outer surface of a portion of a conductive elongate member, at 11. The fdl material may be disposed around the portion of the conductive elongate member while in a solid state. For example, the fdl material may be formed into a foil or sheet that may be disposed over the portion of the conductive elongate member (e.g., in one or more layers) such that an entirety of the outer surface of the portion of the conductive elongate member is covered. In some embodiments, the fdl material may be a soft material in a solid state such that the fdl material can mold to an irregular shape. In some embodiments, the fdl material may include any suitable material such as for example, indium, tin, copper, silver, bismuth, zinc, antimony, etc.

[0133] In some embodiments, the method 10 may optionally include disposing a conductive layer around the fill material to at least partially cover the fdl material, at 12. The conductive layer may be configured to provide a low-resistance electrical pathway between theconductive elongate member and the surrounding terminal structure. In some embodiments, the conductive layer includes a conductive tube formed from a metal foil. In some embodiments, the conductive tube can be formed from copper. In some embodiments, the conductive tube may include aluminum, silver, or other suitable conductive materials. In some embodiments, the conductive tube may be secured using copper tape.{0134 In some embodiments, the method 10 may include disposing a support material (not shown) underneath the inner sleeve 210. The support material may be configured to maintain concentric alignment between the conductive elongate member and the inner sleeve 210 prior to compression. In some embodiments, the support material may be formed from a compliant or non-conductive material selected to accommodate mechanical tolerances and / or prevent misalignment during assembly.

[0135] At 13, the method 10 includes disposing an inner sleeve 210 including a first end, a second end, and a central portion around the portion of the conductive elongate member such that the fill material is disposed between the inner sleeve 210 and the outer surface of the portion of the conductive elongate member. In some embodiments, the inner sleeve 210 may be configured to deform such that an inner surface of the inner sleeve 210 in the deformed configuration contacts the outer surface of the conductive elongate member.[0136| The inner sleeve 210 may include a plurality of slots extending longitudinally along the inner sleeve 210 and positioned circumferentially around the inner sleeve 210 to allow the inner sleeve 210 to deform. The first end portion and the second end portion of the inner sleeve may taper from a first diameter to a second diameter smaller than the first diameter to allow the inner sleeve 210 to deform to a shape corresponding to the conductive elongate member.

[0137] At 14, the method 10 includes disposing a first outer sleeve around the first end portion of the inner sleeve 210 and a second outer sleeve around the second end portion of the inner sleeve 210. At 15, the method includes coupling the first outer sleeve 222 to the second outer sleeve 224 such that the inner sleeve applies a substantially uniform clamping pressure to the conductive elongate member. For example, an axial force may be applied to the first outer sleeve and the second outer sleeve to push the first outer sleeve and the second outer sleeve up the tapered portions (e.g., toward the central portion of the inner sleeve 210). In some embodiments, moving the first outer sleeve and second outer sleeve from an end of each tapered portion towards the central portion of the inner sleeve 210 may cause the inner sleeve 210 to deform radially inward, thereby applying a radial clamping force on the conductive elongatemember. In some embodiments, the first outer sleeve 222 and the second outer sleeve 224 may be coupled to one another via one or more connectors disposed through one or more openings defined in the first outer sleeve 222 and the second outer sleeve 224. In some embodiments, when the inner sleeve 210 applies the clamping pressure to the conductive elongate member, the fill material may deform (e.g., without any application of heat) to fill voids or gaps between the inner sleeve 210 and the conductive elongate member to reduce a contact resistance therebetween.[0138| At 16, the method 1300 may optionally include performing at least one of injecting a current into or withdrawing a current from the conductive elongate member via the inner sleeve, the first outer sleeve, and the second outer sleeve. For example, the first outer sleeve and the second outer sleeve may each have one or more mating features 230 such that a current source and / or current sink may be coupled thereto. The inner sleeve and the outer sleeves may be formed form or include a conductive material such that current can flow across the inner sleeve and the outer sleeves.[0139J All combinations of the foregoing concepts and additional concepts discussed herewithin (provided such concepts are not mutually inconsistent) are contemplated as being part of the subject matter disclosed herein. The terminology explicitly employed herein that also may appear in any disclosure incorporated by reference should be accorded a meaning most consistent with the particular concepts disclosed herein.(01401 The drawings are primarily for illustrative purposes and are not intended to limit the scope of the subject matter described herein. The drawings are not necessarily to scale; in some instances, various aspects of the subject matter disclosed herein may be shown exaggerated or enlarged in the drawings to facilitate an understanding of different features. In the drawings, like reference characters generally refer to like features (e.g., functionally similar, and / or structurally similar elements).[0141 J The entirety of this application (including the Cover Page, Title, Headings, Background, Summary, Brief Description of the Drawings, Detailed Description, Embodiments, Abstract, Figures, Appendices, and otherwise) shows, by way of illustration, various embodiments in which the embodiments may be practiced. The advantages and features of the application are of a representative sample of embodiments only and are not exhaustive and / or exclusive. Rather, they are presented to assist in understanding and teach the embodiments and are not representative of all embodiments. As such, certain aspects of thedisclosure have not been discussed herein. That alternate embodiments may not have been presented for a specific portion of the innovations or that further undescribed alternate embodiments may be available for a portion is not to be considered to exclude such alternate embodiments from the scope of the disclosure. It will be appreciated that many of those undescribed embodiments incorporate the same principles of the innovations and others are equivalent. Thus, it is to be understood that other embodiments may be utilized, and functional, logical, operational, organizational, structural, and / or topological modifications may be made without departing from the scope and / or spirit of the disclosure. As such, all examples and / or embodiments are deemed to be non-limiting throughout this disclosure.[0142| Also, no inference should be drawn regarding those embodiments discussed herein relative to those not discussed herein other than it is as such for purposes of reducing space and repetition. For instance, it is to be understood that the logical and / or topological structure of any combination of any program components (a component collection), other components and / or any present feature sets as described in the figures and / or throughout are not limited to a fixed operating order and / or arrangement, but rather, any disclosed order is exemplary and all equivalents, regardless of order, are contemplated by the disclosure.[0143| The term "determining" encompasses a wide variety7of actions and, therefore, “determining” can include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database, or another data structure), ascertaining and the like. Also, “determining” can include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory') and the like. Also, “determining” can include resolving, selecting, choosing, establishing and the like.10144] The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.”

[0145] Various concepts may be embodied as one or more methods, of which at least one example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. As such, some of these features may be mutually contradictory, in that they cannot be simultaneously present in asingle embodiment. Similarly, some features are applicable to one aspect of the innovations, and inapplicable to others.[0146| In addition, the disclosure may include other innovations not presently described. Applicant reserves all rights in such innovations, including the right to embodiment such innovations, file additional applications, continuations, continuations-in-part, divisional, and / or the like thereof. As such, it should be understood that advantages, embodiments, examples, functional, features, logical, operational, organizational, structural, topological, and / or other aspects of the disclosure are not to be considered limitations on the disclosure as defined by the embodiments or limitations on equivalents to the embodiments.[0147| All definitions, as defined and used herein, should be understood to control over dictionary definitions, definitions in documents incorporated by reference, and / or ordinary meanings of the defined terms.

[0148] As used herein, in particular embodiments, the terms “about” or “approximately” when preceding a numerical value indicates the value plus or minus a range of 10%. Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed wi thin the disclosure. That the upper and lower limits of these smaller ranges can independently be included in the smaller ranges is also encompassed within the disclosure, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0149] The indefinite articles “a” and “an,” as used herein in the specification and in the embodiments, unless clearly indicated to the contrary7, should be understood to mean “at least one.”

[0150] The phrase “and / or,” as used herein in the specification and in the embodiments, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively7present in other cases. Multiple elements listed with “and / or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and / or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and / or B”, whenused in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0151] As used herein in the specification and in the embodiments, “or” should be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the embodiments, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e., “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the embodiments, shall have its ordinary7meaning as used in the field of patent law.[0152| As used herein in the specification and in the embodiments, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and even7element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and / or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one. optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.[01531 In the embodiments, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including butnot limited to. Only the transitional phrases "consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

CLAIMS1. An apparatus, comprising:an inner sleeve including a first end portion, a second end portion, and a central portion between the first end portion and the second end portion, the inner sleeve defining an inner volume configured to receive a portion of a conductive elongate member; anda pair of outer sleeves including a first outer sleeve and a second outer sleeve, the first outer sleeve configured to be disposed around the first end portion of the inner sleeve and the second outer sleeve configured to be disposed around the second end portion,the inner sleeve defining one or more slots and tapering from the central portion to each of the first end portion and the second end portion such that when the first outer sleeve and the second outer sleeve are disposed around the inner sleeve, the inner sleeve deforms to distributes a clamping pressure to the portion of the conductive elongate member,the inner sleeve, the first outer sleeve, and the second outer sleeve including a conductive material such that a current can be injected or withdrawn from the conductive elongate member.

2. The apparatus of claim 1, wherein the clamping pressure is substantially uniform radially about the portion of the conductive elongate member and along a length of the portion of the conductive elongate member.

3. The apparatus of claim 1, wherein the conductive elongate member is a superconducting cable, the superconducting cable includes a former and a plurality of superconducting bands wrapped helically around the former.

4. The apparatus of claim 1, further including:a fill material disposed between the inner sleeve and an outer surface of the conductive elongate member, the fill material configured to fill gaps between the conductive elongate member and an inner surface of the inner sleeve when the inner sleeve applies the clamping pressure to the portion of the conductive elongate member and without heat being applied.

5. The apparatus of claim 1, wherein the apparatus is disposed at a terminal end of the conductive elongate member.

6. The apparatus of claim 1, wherein the clamping pressure is within a predetermined range.

7. The apparatus of claim 1, wherein when the apparatus is coupled to the elongate conductive member, a contact resistance between the conductive elongate member and the apparatus is below720pQ.

8. The apparatus of claim 1, wherein an inner surface of the first outer sleeve tapers according to the tapering of the first end portion and an inner surface of the second outer sleeve tapers according to the tapering of the second end portion,an outer surface of each of the first outer sleeve and the second outer sleeve includes at least one portion including one or more mating features for coupling to a current source.

9. The apparatus of claim 1, wherein the conductive material includes at least one of copper or aluminum.

10. The apparatus of claim 1, wherein the one or more slots defined in the inner sleeve extend longitudinally along the first end portion and the second end portion of the inner sleeve, the one or more slots spaced circumferentially around the inner sleeve.

11. An apparatus, comprising:an inner sleeve defining an inner volume configured to receive a conductive elongate member, the inner sleeve having a first tapered portion and a second tapered portion, a wide end of the second tapered portion coupled to and abutting a narrow7end of the first tapered portion;a first outer sleeve configured to be disposed around the first tapered portion, the first tapered portion defining a plurality of slots such that, when the first outer sleeve is disposed around the first tapered portion, the first tapered portion deforms to distributes a clamping pressure to a first portion of the conductive elongate member;a second outer sleeve configured to be disposed around the second tapered portion the second tapered portion defining a plurality of slots such that, when the second outer sleeve is disposed around the second tapered portion, the second tapered portion deforms to distributes a clamping pressure to a second portion of the conductive elongate member; andan end cap coupled to a terminal end of the conductive elongate member.

12. The apparatus of claim 11, wherein the first tapered portion and the second tapered portion each taper from a central portion of the inner sleeve to a respective end.

13. The apparatus of claim 11 , further comprising:a fill material disposed between the inner sleeve and an outer surface of the first portion and the second portion of the conductive elongate member, the fill material configured to fill gaps between the outer surface of the first portion and the second portion of the conductive elongate member and an inner surface of the inner sleeve when the inner sleeve applies the clamping pressure and without heat being applied.

14. The apparatus of claim 13, wherein the fill material comprises an indium foil.

15. The apparatus of claim 13, further comprising:a conductive tube disposed around the indium foil to at least partially cover the indium foil.

16. The apparatus of claim 11, wherein the end cap is configured to urge the first outer sleeve and the second outer sleeve up the respective tapered portions of the inner sleeve to deform the inner sleeve and apply the clamping pressure.

17. The apparatus of claim 11, wherein the conductive elongate member is a superconducting cable, the superconducting cable includes a former and a plurality of superconducting bands wrapped helically around the former.

18. A method, comprising:disposing a fill material around a portion of a conductive elongate member; disposing an inner sleeve around the fill material, the inner sleeve including a first end portion, a second end portion, and a central portion;disposing a first outer sleeve around the first end portion of the inner sleeve and a second outer sleeve around the second end portion of the inner sleeve; andcoupling the first outer sleeve to the second outer sleeve such that the inner sleeve applies a substantially uniform pressure to the conductive elongate member.

19. The method of claim 18, further comprising:disposing a conductive tube around the fill material to at least partially cover the fill material prior to disposing the inner sleeve.

20. The method of claim 19, wherein the conductive tube comprises copper.

21. The method of claim 18, wherein the fill material comprises indium foil.

22. The method of claim 18, further comprising:injecting a current into or withdrawing a current from the conductive elongate member.

23. The method of claim 18, wherein the conductive elongate member is a superconducting cable, the superconducting cable includes a former and a plurality of superconducting bands wrapped helically around the former.

Images