Magnetic Rotation Device for High-Vacuum Applications Such as Ion and Isotope Generation

Abstract

The apparatus includes a wall defining a boundary of a vacuum space and having a first side inside the vacuum space and a second side outside the vacuum space, a first plate disposed on the first side of the wall and including a first magnet, a second plate disposed on the second side of the wall and including a second magnet, and a motor mechanically coupled to the second plate and configured to drive rotation of the second plate, the second magnet exerting an attractive force on the first magnet which rotates the first plate in response to rotation of the second plate.

Description

Technical Field

[0001] Field The present disclosure relates, in some aspects, to the field of ion and / or isotope generation, such as the generation of heavy metal ions or isotopes for use in medical applications. In other aspects, the present disclosure relates to actuators and other devices suitable for use in a high vacuum enclosure, such as those that can be used for ion and / or isotope generation.

Summary of the Invention

[0002] Summary One implementation of the present disclosure is an apparatus. The apparatus includes a wall that defines a boundary of a vacuum space and has a first side inside the vacuum space and a second side outside the vacuum space, a first plate disposed on the first side of the wall and including a first magnet, a second plate disposed on the second side of the wall and including a second magnet, and a motor mechanically coupled to the second plate and configured to drive rotation of the second plate. The second magnet exerts an attractive force on the first magnet, causing the first plate to rotate in response to rotation of the second plate.

[0003] In some embodiments, the attractive force enables heat transfer from the first plate to the second plate by bringing the first plate into thermal contact with the wall and the second plate into thermal contact with the wall. The apparatus may further include a cooling coil in thermal contact with the second plate.

[0004] In some embodiments, the apparatus includes a shaft coupled to the wall and having a first end on the first side of the wall and a second end on the second side of the wall. The first plate rests on the first end of the shaft, and the second plate rests on the second end of the shaft. The attractive force can hold the second plate and / or the first plate against the shaft. The apparatus may further include an O-ring disposed around the shaft by the wall. During rotation of the first plate and the second plate, the shaft and the O-ring remain stationary with respect to the wall.

[0005] The first plate and the second plate may have the same shape, for example, circular. In some embodiments, the first plate includes a plurality of additional first magnets, and the second plate also includes a plurality of additional second magnets. The first magnet and the plurality of additional first magnets are spaced apart from each other and are disposed at a distance from the axis of rotation of the first plate, and the second magnet and the plurality of additional second magnets are spaced apart from each other and are disposed at the same distance from the axis of rotation of the second plate.

[0006] In some embodiments, the first plate slides along the first side of the wall during rotation of the first plate, and the second plate slides along the second side of the wall during rotation of the second plate. A fluoropolymer-based dry lubricant can be disposed between the first plate and the first side of the wall to reduce the friction therebetween.

[0007] In some embodiments, the target is attached to the first plate. The target can be configured to capture particles from the ion beam incident thereon. The rotation of the first plate can change the area of the target exposed to the ion beam. The apparatus may further include an ion beam generator configured to generate an ion beam within a vacuum space and direct the ion beam towards the target. The pressure of the vacuum space can be, for example, less than 10 mPa. The apparatus can be an ion generation system.

[0008] Another implementation of the present disclosure is a method. The method includes providing an ion beam incident on a target within a vacuum chamber and rotating the target by driving the rotation of an external plate including an external magnet outside the vacuum chamber and transmitting the rotation of the external plate to an internal plate within the vacuum chamber through the gravitational force between the external magnet and an internal magnet of the internal plate. The target is attached to the internal plate.

[0009] In some embodiments, the method further includes transferring heat from the target to an external plate through an internal plate and the wall of the vacuum chamber. The method further includes operating a refrigeration cycle to cool the external plate.

[0010] In some embodiments, the method further includes driving rotation of the external plate, including operating a stepping motor coupled to the external plate. Rotating the target can increase the area of the target exposed to the ion beam due to misalignment of the ion beam with respect to the axis of rotation of the target. [The present invention 1001] A wall that defines a boundary of a vacuum space and includes a first side inside the vacuum space and a second side outside the vacuum space, A first plate disposed on the first side of the wall and including a first magnet, A second plate disposed on the second side of the wall and including a second magnet, and A motor mechanically coupled to the second plate and configured to drive the rotation of the second plate Including, The second magnet exerts an attractive force on the first magnet, which rotates the first plate in response to the rotation of the second plate, Device. [The present invention 1002] The attractive force is, By bringing the first plate into thermal contact with the wall and bringing the second plate into thermal contact with the wall, Enables heat transfer from the first plate to the second plate, The device of the present invention 1001. [The present invention 1003] The device of the present invention 1001, further including a cooling coil in thermal contact with the second plate. [The present invention 1004] Further includes a shaft coupled to the wall and having a first end on the first side of the wall and a second end on the second side of the wall, The first plate is supported on the first end of the shaft, The second plate is supported on the second end of the shaft, The device of the present invention 1001. [The present invention 1005] The device of the present invention 1004, wherein the second plate is held on the shaft by the attractive force. [The present invention 1006] An O-ring disposed around the shaft by the wall Further including, During the rotation of the first plate and the second plate, the shaft and the O-ring are stationary with respect to the wall, The device of the present invention 1004. [The present invention 1007] The first plate and the second plate have the same size and the same shape, the device of the present invention 1001. [The present invention 1008] The same shape is circular, the device of the present invention 1001. [The present invention 1009] The first plate further includes a plurality of additional first magnets, and the second plate further includes a plurality of additional second magnets, The first magnet and the plurality of additional first magnets are spaced apart from each other and are disposed at a distance from the rotation axis of the first plate, The second magnet and the plurality of additional second magnets are spaced apart from each other and are disposed at a distance from the rotation axis of the second plate, The device of the present invention 1001. [The present invention 1010] The first plate slides along the first side surface of the wall during the rotation of the first plate, and the second plate slides along the second side surface of the wall during the rotation of the second plate, the apparatus of the present invention 1001. [The present invention 1011] A fluoropolymer-based dry lubricant disposed between the first plate and the first side surface of the wall to reduce friction therebetween The apparatus of the present invention 1009, further comprising. [The present invention 1012] The apparatus of the present invention 1001, further comprising a target attached to the first plate, the target being configured to capture particles from an ion beam incident thereon. [The present invention 1013] The apparatus of the present invention 1012, wherein the rotation of the first plate changes the area of the target exposed to the ion beam. [The present invention 1014] configured to generate the ion beam within the vacuum space and direct the ion beam toward the target Ion beam generator The apparatus of the present invention 1012, further comprising. [The present invention 1015] The apparatus of the present invention 1001, which is an ion generation system. [The present invention 1016] Providing an ion beam incident on a target within a vacuum chamber Rotating the target by driving the rotation of an external plate including an external magnet outside the vacuum chamber and transmitting the rotation of the external plate to an internal plate within the vacuum chamber through the attractive force between the external magnet and an internal magnet of the internal plate, wherein the target is attached to the internal plate Including, method. [The present invention 1017] The method of the present invention 1016, further comprising transferring heat from the target to the external plate through the internal plate and the wall of the vacuum chamber. [The present invention 1018] The method of the present invention 1017, further comprising operating a refrigeration cycle to cool the external plate. [The present invention 1019] Driving the rotation of the external plate includes operating a stepping motor coupled to the external plate, the method of the present invention 1016. [The present invention 1020] When the target is rotated, the area of the target exposed to the ion beam increases due to the displacement of the ion beam with respect to the rotation axis of the target, the method of the present invention 1017.

Brief Description of the Drawings

[0011] This disclosure can be more fully understood by combining the accompanying drawings with the following detailed description, and like reference numerals refer to like elements.

[0012] [Figure 1] FIG. 5 is a block diagram of an ion generation system according to some embodiments.

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0013] DETAILED DESCRIPTION Before turning to the drawings that illustrate certain embodiments in detail, it is to be understood that this disclosure is not limited to the details or methodology set forth in the description or illustrated in the drawings. It is also to be understood that the terminology used herein is for the purpose of description only and should not be regarded as limiting.

[0014] Generally referring to the drawings, systems and methods related to a magnetic rotation device, for example for use in an ion generation system, are shown. The generation of ions or isotopes can be performed at a high vacuum (e.g., a pressure less than 10 mPa) to avoid contamination between the particles to be generated and air or other contaminants. Accordingly, a vacuum chamber (such as a sealed enclosure, an airtight box, etc.) can be provided to house various components of the ion generation system. However, depending on the scenario, it may be preferable to have certain components outside the vacuum chamber for reasons such as contamination reduction, ease of maintenance and assembly, ease of use, and reduction of the size requirements of the vacuum chamber.

[0015] In this regard, the present application includes the determination that it is desirable to provide an apparatus that can transfer heat from (or to) the vacuum chamber without including an airtight seal of the vacuum chamber, and at the same time transfer mechanical action from outside the vacuum chamber into the vacuum chamber. In the main example of this specification, a magnetic rotation device is provided to rotate the target of the ion beam in the ion generation system and at the same time release heat from the target. Other uses and applications of the magnetic rotation device described in this specification are also within the scope of the present disclosure. As will be described below, the electric motor that drives the rotation can be arranged outside the vacuum chamber, and the cooling coil, refrigeration cycle device, etc. included to promote heat transfer are the same.

[0016] The systems and methods described herein thereby provide various advantages such as facilitating maintenance, control, assembly / disassembly, and improving the airtightness of the vacuum chamber, while also achieving the technical goal of rotating components within the vacuum chamber and providing heat transfer across the walls of the vacuum chamber. In the context of the ion generation system described below, operating the magnetic rotation device enables collection of a larger amount of ions and / or isotopes, longer continuous operation of the generation system, and thermal management of the target, thereby improving the efficiency of the ion and / or isotope generation system.

[0017] Referring now to FIG. 1, a block diagram of an ion generation system 100 according to some embodiments is shown. The ion generation system 100 includes an ion source 102, optional extraction electrode(s) 104, a magnetic analyzer 106, a mass spectrometry aperture 108, a target 110, and a voltage source 112 connected to the target 110 and an earth terminal 114. The ion source 102, the optional extraction electrode(s) 104, the magnetic analyzer 106, the mass spectrometry aperture 108, and the target 110 are arranged in sequence. As a result, ions are generated at the ion source 102 and sequentially pass through the optional extraction electrode(s) 104, the magnetic analyzer 106, and the mass spectrometry aperture 108 before reaching the target 110. As will be described in detail below, the ion generation system 100 is configured to efficiently collect desired ions at the target 110 as a configured neutral substance that can be removed, stored, transported, etc. and ultimately used for some application, such as a medical application.

[0018] The ion source 102 is configured to generate ions. For example, the ion source 102 can be configured as a Bernas or Freeman ion source that includes a filament operable to emit electrons that ionize a gas supplied into the ion source 102, such as a heavy metal gas like ytterbium vapor. Other metals (such as Lu, Tc, etc.) can also be used. Due to the interaction between the electrons and the gas, the gas is ionized and ions are generated. In some embodiments, the ion source 102 generates positive ions (i.e., "cations," ions having a positive polarity). In another embodiment, the ion source generates negative ions (i.e., "anions," ions having a negative polarity). The ion source 102 includes an exit slit or aperture to extract ions from the ion source 102. In some embodiments, the ion source 102 includes an auxiliary heater to protect the elements of the ion source 102 and improve the uniformity of the ions extracted from the ion source 102, as described in detail in, for example, U.S. Provisional Patent Application No. 63 / 122,699, filed on December 8, 2020, the entire disclosure of which is incorporated herein by reference.

[0019] The extraction electrode(s) 104 includes one or more electrodes configured and operative to provide an electric field for extracting ions from the ion source 102. Since the ions have a charge of a first polarity (positive or negative in different embodiments), the voltage of the opposite polarity at the extraction electrode(s) 104 will extract the ions from the ion source as an ion beam. The extraction electrode(s) 104 may include one or more electrodes for accelerating the ion beam, decelerating the ion beam, shaping the beam, directing the beam, etc. By providing an electric field for accelerating the ion beam from the ion source 102, the extraction electrode(s) 104 provides the ion beam with an extraction energy of the same or similar magnitude as the voltage of the extraction electrode(s) 104. For example, an electrode with a voltage of 55 kV can provide the ion beam with an extraction energy of 55 kV as the ion beam passes through the extraction electrode(s) 104 (note that in this context, the kinetic energy of the ions is often expressed in volts, where 1 volt is equal to 1 joule per coulomb).

[0020] Accordingly, an ion beam having a high extraction energy is provided as the output of the extraction electrode(s) 104. In various embodiments, the high extraction energy can be in the range of 20 kV to 80 kV, such as 40 kV to 60 kV (e.g., 55 kV). In such embodiments, the voltage applied to the extraction electrode(s) 104 can be selected to provide the ion beam with the desired extraction energy for a particular scenario.

[0021] In the example of FIG. 1, the ion beam passes from extraction electrode 104 to magnetic analyzer 106. In another embodiment, magnetic analyzer 106 is omitted. Magnetic analyzer 106 is configured to provide a magnetic field that generates a magnetic force on the ion beam. The magnetic force on each ion may be approximately equal, but since the ion beam may contain ions of different isotopes, the mass of the ions is different. The magnetic force provided by magnetic analyzer 106 can result in separation of the ions by mass. Thus, after passing through magnetic analyzer 106, each region of the cross-section of the ion beam may contain ions of each isotope, i.e., ions of each mass.

[0022] In FIG. 1, the ion beam is shown to pass from magnetic analyzer 106 to mass analysis aperture 108, and mass analysis aperture 108 is configured to prevent an undesired subset of ions from passing through mass analysis aperture 108 while allowing the desired ions to pass through mass analysis aperture 108. In particular, the ions that can pass through mass analysis aperture 108 are mainly ions of the desired isotope (or two desired isotopes), but ions of one or more other isotopes are blocked by mass analysis aperture 108. This is achieved by positioning mass analysis aperture 108 relative to magnetic analyzer 106 in order to utilize the isotope separation by mass achieved by magnetic analyzer 106. In various embodiments, various geometric arrangements are possible. Thus, in an example including magnetic analyzer 106 and mass analysis aperture 108, the ion beam reaching target 110 contains a high percentage (%) of the desired isotope and a low percentage (%) of contamination by ions of different isotopes.

[0023] The ion beam from the mass spectrometry aperture 108 is incident on the target 110. The target 110 is configured to receive and collect the ions of the ion beam. The target 110 may include a substrate material suitable for receiving and holding ions, including as a film on the surface of the target 110 and / or embedded in the lattice structure of the target 110. For example, the substrate material of the target 110 may have a crystal structure. As another example, the substrate material of the target 110 may include a carbon fiber material (e.g., carbon fiber cloth). The material(s) of the target 110 are also selected such that the target 110 can be maintained at a substantially constant voltage when ions are collected, implanted, or otherwise received at the target 110. The material(s) of the target 110 may be selected to help cause the attachment of ions to the target 110 or into the target 110. The target 110 may be removable and replaceable within the ion generation system 100 to facilitate the collection of the ion material that accumulates on the target 110 during the operation of the ion source 102.

[0024] The target 110 is shown to be coupled to a voltage source 112 connected between the target 110 and the ground terminal 114. Other elements of the ion generation system 100 also include appropriate electronic elements, power supplies, etc. that enable its operation. The voltage source 112 is configured to hold (position, establish, maintain, etc.) the target 110 at a voltage (referred to herein as the target voltage) having the same polarity as the ion beam. For example, in the scenario where positive ions are generated by the ion source as shown in FIGS. 2 - 3 and described below, a positive voltage is provided to the target 110 by the voltage source 112, while in the scenario where negative ions are generated by the ion source, a negative voltage is provided to the target 110 by the voltage source 112.

[0025] The target voltage is preferably lower than the extraction energy of the ion beam so that the ion beam can reach the target without being forced in the opposite direction by the target voltage. On the other hand, it is high enough to reduce the energy of the ion beam sufficiently to minimize both the electronic and nuclear stopping of the ion beam at the target 110 (thereby minimizing scattering or sputtering caused by high-energy collisions between the ions and the target 110 that would otherwise occur). For example, the target voltage may be less than the extraction energy by an amount corresponding to the thermal energy of the ions such that the energy of the ions is reduced to thermal energy when they reach the target 110. In various embodiments, the target voltage is less than the extraction energy and greater than 95% of the extraction energy, for example, greater than 99% of the extraction energy (while being less than the extraction energy). In some examples, the target voltage is approximately 100 V lower than the extraction energy so that the ion beam has an energy of approximately 100 V when it reaches the target (for example, the value obtained by subtracting the target voltage from the extraction energy is equal to approximately 100 V). In one example, the target energy is 55 kV and the target voltage is 54.9 kV.

[0026] In some embodiments, the voltage source 112 and the target 110 are configured such that during operation of the ion generation system 100 and when ions are collected on the target 110 (e.g., as a film on the target 110, embedded in the target 110) and are configured into neutral substances (e.g., of the desired isotope(s)), the voltage of the target 110 is kept substantially constant. Optionally, the target 110 can be made removable from the ion generation system 100 to facilitate removal of the configured ionized substance from the target 110. In such a case, the voltage source 112 is controlled to gradually decrease the target voltage towards zero so that the target 110 can be disconnected from the voltage source 112 without destroying the ionized substance collected on the target 110. In some embodiments, the target 110 (or a part thereof) is removed for use in the transport and further processing of the ionized substance and is replaced with a new target 110 (or a new part thereof) for use in subsequent operation of the ion generation system 100. In another embodiment, the ionized substance is removed from the target 110 and collected in a container (or other collection and holding device), such that the target 110 can be reused in subsequent operation of the ion generation system 100 so that more ions can be collected.

[0027] Referring now to FIG. 2, a schematic diagram of an apparatus 200 including a vacuum chamber 202, an ion generation system 204, and a magnetic rotation device 206, according to some embodiments, is shown.

[0028] The ion generation system 204 is shown as including an ion beam generator 208 and a target 210. The ion beam generator 208 is configured to generate an ion beam and direct the ion beam towards the target 210 such that the ion beam is incident on the target 210. The ion beam generator 208 can include, for example, the ion source 102, extraction electrode 104, magnetic analysis device 106, and / or mass analysis aperture 108 of FIG. 1. The target 210 can be configured similarly to the target 110 of FIG. 1, for example.

[0029] As shown in FIG. 2, the target 210 is coupled to the magnetic rotating device 206. The magnetic rotating device 206 includes an inner plate (first plate) 212, an outer plate (second plate) 214, and a motor 216. The inner plate 212 is inside the vacuum chamber 202 (inside, within, included in the interior), and is disposed on the inner side 218 of the wall 220 of the vacuum chamber 202. The outer plate 214 is outside the vacuum chamber 202 (outside, exterior, not included in the interior), and is disposed on the outer side 222 of the wall 220. The motor 216 is mechanically coupled to the outer plate 214. The target 210 is mechanically coupled to the inner plate 212.

[0030] The motor 216 is operable to drive the rotation of the outer plate 214. The motor 216 can be an electric motor that converts electricity into rotational motion, such as a stepping motor. The motor 216 is coupled to the outer plate 214 such that the operation of the motor 216 exerts torque on the outer plate 214 and causes the rotation of the outer plate 214 about the axis of the outer plate 214. The rotational drive shaft of the motor 216 is aligned with the axis of the outer plate 214 to directly transmit torque to the outer plate 214 and rotate the outer plate 214. The motor 216 is controllable to rotate the outer plate 214 at various speeds. In some embodiments, the motor 216 operates to rotate the outer plate 214 at a pace of about one rotation per minute.

[0031] The outer plate 214 includes one or more magnets (e.g., permanent magnets), and the inner plate 212 also includes one or more magnets (e.g., permanent magnets) corresponding to the one or more magnets of the outer plate 214. Exemplary arrangements of the magnets in the inner plate 212 and the outer plate 214 are shown in FIGS. 3 - 6 and are described with reference thereto. The magnets of the outer plate 214 and the inner plate 212 are arranged such that an attractive force acts on the inner plate 212 by the outer plate 214 and vice versa. For example, one or more magnets of the outer plate 214 may be arranged with a positive magnetic pole facing the wall 220, while one or more magnets of the inner plate 212 may be arranged with a negative magnetic pole facing the wall 220 (or vice versa), so that the magnets are attracted to each other and the inner plate 212 and the outer plate 214 are attracted by the magnetic force. The magnets provide a magnetic field strong enough to exert an attractive force across the wall 220 of the vacuum chamber 202. In some embodiments, the thickness of the wall 220 can be about 0.5 inches.

[0032] Due to the attractive force of the magnetic force between the magnets of the outer plate 214 and the inner plate 212, the rotation of the outer plate 214 by the motor 216 causes the rotation of the inner plate 212. In the illustrated example, the inner plate 212 rotates in accordance with the rotation of the outer plate 214 due to the magnetic coupling therebetween. Thereby, rotational motion and torque (e.g., angular kinetic energy) are transmitted across the wall 220 of the vacuum chamber 202 without compromising the integrity of the airtight seal of the vacuum chamber 202 (e.g., without requiring a mechanical engagement between the inner plate 212 and the outer plate 214 that is difficult to airtight seal). As shown in FIG. 2, since the target 210 is attached to the inner plate 212, the target 210 rotates due to the rotation of the inner plate 212. Although the examples herein refer to rotation, in other embodiments, the motor 216 is configured to move the outer plate 214 (e.g., in one or two dimensions), thereby causing a corresponding movement of the inner plate 212 and the target 210. Thus, the operation of the motor 216 causes the movement of the target 210, e.g., the rotation of the target 210.

[0033] As shown in FIG. 2, the ion beam generator 208 directs the ion beam toward the target 210 such that the ion beam is misaligned (offset, etc.) with respect to the axis of rotation of the target 210. Accordingly, when the target 210 rotates due to the operation of the magnetic rotation device 206, the point or region at which the ion beam impinges on the target 210 changes. As the target 210 rotates over time, the ion beam impinges on different portions of the target 210 over time, thereby increasing the total area of the target 210 that is exposed to the ion beam. Accordingly, the movement of the target 210 exposes a larger area of the target 210 to the ion beam, enabling the capture of ions and / or isotopes from the ion beam. Accordingly, the target 210 can capture more material compared to embodiments having a stationary target 210, and the device 200 can be operated continuously for a longer time before the target becomes full (saturated, reaches capacity, etc.). Rotating the target can also reduce temperature gradients across the target, which may be undesirable.

[0034] The magnetic rotation device 206 is also configured to provide heat transfer to and from the vacuum chamber, for example, to remove heat from the target 210 and manage its temperature. As shown, both the inner plate 212 and the outer plate 214 are disposed in contact with the wall 220 of the vacuum chamber 202. The inner plate 212 and the outer plate 214 may include a material having a high thermal conductivity (e.g., low resistance to heat flow therethrough), such as a metal like steel. The wall 220 can be made of a similar material. The inner plate 212 and the outer plate 214 are in thermal contact with each other via the wall 220. Such thermal contact is maintained by the attractive force between magnets of the inner plate 212 and the outer plate 214 that can press the inner plate 212 and the outer plate 214 against each other and into contact with the wall 220. The target 210 is shown to be disposed on the inner plate 212. Thereby, a heat transfer path from the target 210 to the outer plate 214 is formed.

[0035] In the illustrated embodiment, the apparatus 200 also includes a cooling system 224 in thermal communication with the outer plate 214. The cooling system 224 may include a refrigeration cycle (e.g., including a compressor, a condenser, an expansion valve, and an evaporator) configured to remove heat from the outer plate 214. For example, the cooling system 224 can provide a cooling fluid through one or more coils or other heat exchangers in thermal contact with the outer plate 214. Cooling of the outer plate 214 increases the heat flow away from the target 210, which may be desirable in embodiments where the collision of the ion beam with the target 210 provides thermal energy to the target 210. In another scenario (e.g., other uses of the magnetic rotation device 206), the cooling system 224 includes, or can be replaced with, a heating system configured to provide thermal energy to the outer plate 214 to transfer thermal energy (heat) to the vacuum chamber 202 via the inner plate 212.

[0036] Referring now to FIGS. 3-6, multiple views of a magnetic rotation device 206 according to some embodiments are shown. Other designs of magnetic rotation devices are also within the scope of the present disclosure. FIG. 3 shows an isometric view mainly showing the outer plate 214, FIG. 4 shows an isometric view mainly showing the inner plate 212, FIG. 5 shows a side cross-sectional view, and FIG. 6 shows a front view of the outer plate 214. In the following description, reference is made to FIGS. 3-6. FIGS. 3-6 show a magnetic rotation device 206 attached to the wall 220 of the vacuum chamber 202.

[0037] The outer plate 214 is shown as a ring-shaped, particularly circular, disk. In other embodiments, the outer plate 214 can be of another shape (e.g., polygonal, non-polygonal, rectangular, square, pentagonal, hexagonal, heptagonal, octagonal, etc.). The outer plate 214 has, in the illustrated example, a first flat surface 300 that fits against the outer side 222 of the wall 220, a second flat surface 302 opposite the first flat surface 300, and a peripheral surface 304 extending from the first flat surface 300 to the second flat surface 302. A dry lubricant, such as a fluoropolymer, can be disposed on the first flat surface 300 and / or the outer side 222 of the wall 220 to reduce the sliding friction therebetween and facilitate the rotation of the outer plate 214 along the wall 220.

[0038] The outer plate 214 is shown as including a hub 306 on the central axis of the outer plate 214. The hub 306 is shown as a cylindrical opening that defines the axis of rotation of the outer plate 214.

[0039] The hub 306 is configured to receive the shaft 500 (as best shown in FIG. 5), particularly the outer end 502 of the shaft 500 extending from the outer side 222 of the wall 220. The shaft 500 also includes an inner end 504 that extends into the vacuum chamber 202 from the opposite side of the outer end 502, i.e., from the inner side 218 of the wall 220. In the illustrated example, the outer end 502 of the shaft 500 has a radius that matches the size of the cylindrical opening of the hub 306, while the narrower connecting section 506 of the shaft 500 extends through the hole in the wall 220 to the inner end 504 of the shaft 500. In another embodiment, the outer end 502 and the inner end 504 are formed directly in the wall 220 without a connecting section 506 extending through the wall 220. An O-ring 508 is provided between the outer end 502 of the shaft 500 and the outer side 222 of the wall 220 to provide an airtight seal of the outer end 502 against the outer side 222 of the wall 220 to prevent pressure leakage in the shaft 500.

[0040] In the illustrated embodiment, the hub 306 is configured to rotate (spin, turn, etc.) about the shaft 500 while the shaft 500 remains stationary. The hub 306 can be selectively slid onto and off of the shaft, for example, during the assembly or disassembly of the magnetic rotating device 206. The magnetic forces described below are sufficient to hold the outer plate 214 against the shaft 500 in the absence of an external force on the outer plate 214 (e.g., a force from a technician pulling the outer plate 214 away from the wall 220). In some embodiments, a snap-on plate or other retaining mechanism can be engaged with the outer ends 502 of the hub 306 and the shaft 500 to hold the hub 306 and the outer plate 314 to the hub 306.

[0041] The outer plate 214 also includes a plurality of magnets shown as four magnets 308. The magnets 308 can be permanent magnets having a stable magnetic polarity such that each magnet 308 provides a substantially static magnetic field at rest. The four magnets 308 can be oriented in a common direction such that their polarities are aligned. For example, all four magnets 308 can be aligned with a positive polarity facing the wall 220. As another example, all four magnets 308 can be aligned with a negative polarity facing the wall 220. In this example, four magnets 308 are shown, but any number of magnets (e.g., 1, 2, 3, 4, 5, 6, 7, 8, etc.) can be used in various embodiments.

[0042] The magnets 308 are disposed in recesses (openings, slots, containers, etc.) in the second flat surface 302 of the outer plate 214 such that the magnets 308 are disposed adjacent to the first flat surface 300 and provide a magnetic field across the first flat surface 300. The magnets 308 can be mechanically held within the recesses (e.g., coupled to other structures of the outer plate 214 using clips, bolts, etc., screwed into the recesses, high friction between the magnet 308 and the recess, adhered to the recess, etc.) and / or held within the recesses by the magnetic forces acting thereon. In the examples of FIGS. 3 - 6, the magnets 308 are cylindrical.

[0043] The magnet 308 is equidistant from the hub 306 and from the axis of rotation of the external plate 214 (e.g., from the center of the axis 500). For example, all of the magnets 308 can be separated from the axis of rotation of the external plate 214 by a predetermined radius. With this arrangement, when the external plate 214 rotates, the magnets 308 move along a common path, specifically along the same circle having a radius defined by the spacing between the axis of rotation of the external plate 214 and the magnets 308. As shown, the magnets 308 are arranged equidistantly around such a circle or path. This facilitates alignment with the internal plate 212, as will be described later, and facilitates recovery from jamming, skipping, slipping, etc. during the operation of the magnetic rotating device 206.

[0044] As shown, the magnet 308 is arranged near the peripheral surface 304 of the second flat surface 302, i.e., near the periphery of the external plate 214. If a greater distance is provided between the magnet 308 and the axis 500, the load on each magnet 308 generated during rotation of the external plate 214 to rotate the internal plate 212 is reduced. Thus, by arranging the magnets 308 around the circumference of the disk (i.e., near the circumferential surface 304 of the external plate 212), it is possible to use fewer or weaker magnets compared to another embodiment where the magnets are arranged near the axis 500.

[0045] The external plate 214 is also shown as including bolt holes 310. The bolt holes 310 are arranged at various positions on the external plate 214 and are configured to enable attachment of other components, devices, equipment, etc. to the external plate 214. For example, the motor 216 can be coupled to the external plate 214 by using bolts (such as screws) to couple the rotational drive shaft of the motor 216 to at least a subset of the bolt holes 310. The motor 216 can then transmit torque to the external plate 214 via the bolt holes 310. The bolt holes 310 can be threaded to securely connect threaded bolts thereto.

[0046] The inner plate 212 is shown with substantially the same configuration as the outer plate 214, which can facilitate manufacturing and enable easy and reliable alignment between the inner plate 212 and the outer plate 214. However, another compatible design can be used in other embodiments. The inner plate 212 is shown as an annular, particularly circular, disk. In other embodiments, the inner plate 212 can be of another shape (e.g., polygonal, non-polygonal, rectangular, square, pentagonal, hexagonal, heptagonal, octagonal, etc.). The inner plate 212 has, in the illustrated example, a first flat surface 400 that fits inside the wall 220 at 218, a second flat surface 402 on the opposite side of the first flat surface 400, and a peripheral surface 404 extending from the first flat surface 400 to the second flat surface. A dry lubricant, such as a fluoropolymer, can be disposed on the first flat surface 400 and / or the inside of the wall at 218 to reduce the sliding friction therebetween and facilitate the rotation of the inner plate 212 along the wall 220. Other types of lubricants (e.g., oil-based lubricants) may not be suitable for use in the high vacuum within the vacuum chamber 202. In the illustrated example, the shape of the inner plate 212 matches the shape of the outer plate 214. As shown, the inner plate 212 is aligned with the outer plate 214 across the wall 220.

[0047] The inner plate 212 has a hub 406 on the central axis of the inner plate 212. The hub 406 is shown as a cylindrical opening that defines the axis of rotation of the inner plate 212. The hub 406 receives the shaft 500, particularly the inner end 504 of the shaft 500 extending from the inner side 218 of the wall 220. The hub 406 is configured to rotate (spin, turn, etc.) about the shaft 500 while the shaft 500 remains stationary in the illustrated embodiment. In this example, as shown, a snap-on plate (snap ring, retaining member, etc.) 510 is included and engages both a notch or groove in the shaft 500 and a lip or step in the hub 406, holding the snap-on plate 510 on the shaft 500 and preventing the hub 406 from slipping off the shaft 500. Thereby, the hub 406 is held on the shaft 500. In some embodiments, the snap-on plate 510 is omitted, but the magnetic attraction between the inner plate 212 and the outer plate 214 acts to hold the hub 406 on the shaft 500.

[0048] The inner plate 212 includes a plurality of magnets shown as four magnets 408. In this example, four magnets 308 are shown, but in various embodiments, any number of magnets (e.g., 1, 2, 3, 4, 5, 6, 7, 8, etc.) can be used. The magnets 408 can be permanent magnets having a stable magnetic polarity such that each magnet 308 provides a substantially static magnetic field at rest. The four magnets 408 can be oriented in a common direction such that their polarities are aligned, particularly such that their polarities face in a direction opposite to the polarities of the magnets 308 of the outer plate 214. If the magnets 308 of the outer plate 214 are oriented with a positive polarity towards the wall 220, the magnets 408 of the inner plate 212 are oriented with a negative polarity towards the wall 220. If the magnets 308 of the outer plate 214 are oriented with a negative polarity towards the wall 220, the magnets 408 of the inner plate 212 are oriented with a positive polarity towards the wall 220. Thus, the magnetic fields of the magnets 308 of the outer plate 214 and the magnets 408 of the inner plate interact to generate a magnetic force that attracts the inner plate 212 towards the outer plate 214 or vice versa.

[0049] The magnet 408 is disposed adjacent to the first flat surface 400 and is arranged in a recess (opening, slot, container, etc.) of the second flat surface 402 of the internal plate 212 so as to provide a magnetic field that crosses the first flat surface 400. The magnet 408 can be mechanically held within the recess (e.g., coupled to other structures of the internal plate 212 using clips, bolts, screens, etc., screwed into the recess, high friction between the magnet 408 and the recess, adhered to the recess, etc.), and / or can be held within the recess by the magnetic force acting thereon. In the examples of FIGS. 3-6, the magnet 408 is cylindrical.

[0050] The magnet 408 (internal magnet 408) of the internal plate 212 is arranged to be aligned with the magnet 308 (external magnet 308) of the external plate 214. The distance (distance, radius, etc.) between the hub 406 of the internal magnet 408 and the shaft 500 is made to match the distance of the external magnet 308 from the hub 306 and the shaft 500 such that the internal magnet 408 is arranged along the same path as the external magnet 308. Further, the internal magnets 408 are arranged at equal intervals around the above path in accordance with the layout of the external magnets 308.

[0051] As shown in FIGS. 3-6, when both the internal plate 212 and the external plate 214 are attached to the shaft 500 and the wall 220, each of the internal magnets 408 is aligned with one of the external magnets 308. Since the arrangement / layout of the internal magnets 408 and the external magnets 308 is symmetric, there are multiple relative orientations to achieve such alignment. That is, the layout of the magnets 408, 308 is such that the alignment of any one internal magnet 408 with any one external magnet 308 ensures the alignment of the remaining internal magnets 408 with the remaining external magnets 308.

[0052] Once aligned, the magnetic attraction between the internal magnet 408 and the external magnet 308 acts to maintain the alignment such that movement of the external magnet 308 causes movement of the internal magnet 408. Rotation of the external plate 214 (e.g., by manual operation, operation of the motor 216, etc.) causes the external magnet 308 to move along a circular path, thereby causing the internal magnet 408 to move magnetically along the same circular path, thereby rotating the internal plate 212. Due to the matching layout of the internal magnet 408 and the external magnet 308, even if the magnetic connection and alignment between them are temporarily lost during rotation of the external plate 214 (e.g., due to jamming, resistance, inertia, etc.), the external magnet 308 ensures that it will eventually realign with the internal magnet 408 by continuing to rotate along the shared path. Accordingly, the internal magnet 408 and the external magnet 308 are arranged to provide a highly reliable self-healing transmission of rotational motion across the wall 220.

[0053] The internal plate 212 is also shown as including bolt holes 410. The bolt holes 410 are arranged at various positions on the internal plate 212 and are configured to enable attachment of other components, devices, equipment, etc. to the internal plate 212. For example, the target 210 can be coupled to the internal plate 212 by using bolts (such as screws) to couple the target 210 to at least a subset of the bolt holes 410. The internal plate 212 can then transmit torque and rotation to the target 210 via the bolt holes 410. Threads can be cut in the bolt holes 310 to securely connect threaded bolts thereto.

[0054] As shown in FIGS. 3 to 5, the magnetic attraction between the internal magnet 408 and the external magnet 408 draws the internal plate 212 and the external plate 214 into contact with or close to the wall 220. The internal plate 212, the wall 220, and the external plate 214 can be made of the same or similar thermally conductive materials (e.g., metal, steel, etc.), so that when magnetically held together as in FIGS. 3 to 5, for example, across the inner surface region of the first flat surface 400, through the wall 220, through the internal plate 212, to the entire surface area of the first flat surface 300 of the external plate 214, a substantially continuous mass through which heat can flow is provided. The close contact and the large exposed surface area achieve high-efficiency heat transfer across the magnetic rotating device 206.

[0055] The systems described herein can, in various embodiments, enable the following operations. An ion beam can be provided to impinge on a target 210 within a vacuum chamber 202. For example, using a motor 216 (e.g., a stepper motor) coupled to an external plate 214 and likewise disposed outside the vacuum chamber 202, the target 210 can be rotated by driving the rotation of the external plate 214 outside the vacuum chamber 202. The magnet 308 of the external plate 214 exerts a magnetic attraction on the magnet 308 of the internal plate 212 within the vacuum chamber 202, which transmits the rotation of the external plate 214 to the internal plate 212, whereby the rotation is transmitted across the wall 220 of the vacuum chamber 202. The target 210 can be attached to the internal plate 212 such that the rotation of the internal plate 212 causes the rotation of the target 210. Rotating the target 210 can increase the area of the target exposed to the ion beam due to the misalignment of the ion beam with respect to the axis of rotation of the target. Heat can be transferred from the target 210 through the internal plate 212 to the external plate 214 through the wall 220, for example, to cool the target 210. Operating the systems herein can also include operating a refrigeration cycle (e.g., of the cooling system 224) to cool the external plate 214. These and other processes are made possible by the systems and methods described herein.

[0056] As used herein, the terms “about,” “approximately,” “substantially,” and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. These terms are intended to allow a description and claim of certain features without restricting the scope of these features to the precise numerical values or idealized geometric shapes provided. It should be understood by those reviewing this disclosure that these terms are to be interpreted as indicating that non-substantive or insignificant modifications or variations of the described and claimed subject matter are considered to be within the scope of the disclosure as set forth in the appended claims.

[0057] As used herein, the term "coupled" and variations thereof mean joining two members directly or indirectly to each other. Such joining may be stationary (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such joining can be accomplished by directly coupling the two members to each other, using separate intervening members and additional intermediate members that couple the two members to each other, or using intervening members formed integrally with one of the two members to couple the two members to each other. When "coupled" or variations thereof are modified by additional terms (e.g., directly coupled), the general definition of "coupled" above is modified by the plain meaning of the additional term (e.g., "directly coupled" means that two members are joined without an intervening separate member), resulting in a definition that is narrower than the general definition of "coupled" above. Such coupling can be mechanical, electrical, or fluidic.

[0058] References to the position of elements herein (e.g., "upper", "lower", "above", "below") are used solely to describe the orientation of the various elements in the drawings. Note that the orientation of the various elements may vary according to other exemplary embodiments, and such variations are intended to be encompassed by the present disclosure. References to elements such as "first", "second", "additional", etc. are used as non-descriptive labels for the purpose of distinguishing components and can be used in place of other labels or names used herein and should be considered to be fully supported by the present disclosure. For example, the terms "first plate" and "second plate" should be understood as being supported in a non-limiting manner by the disclosure regarding the inner plate and outer plate above.

[0059] In the context of describing elements (especially in the context of the following claims), the terms "a", "an", "the", and the use of similar referents should be construed to cover both the singular and the plural forms, unless otherwise indicated herein or clearly contradicted by the context. The recitation of a range of values herein is merely intended to serve as a shorthand method of referring individually to each separate value within the range, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by the context. The use of any examples, or exemplary language (e.g., "such as") provided herein is for the sole purpose of better understanding the embodiments and does not limit the claims unless otherwise stated. No language in the specification should be construed as indicating any non-claimed element as essential.

[0060] Although the drawings and description may show a particular order of method steps, unless otherwise specified above, the order of such steps may be different from that shown and described. Also, unless otherwise specified above, two or more steps may be performed simultaneously or partially simultaneously. Such variations may depend, for example, on the software and hardware systems selected and the designer's choices. All such variations are within the scope of the present disclosure. Similarly, software implementations of the described methods can be realized using standard programming techniques with rule-based logic and other logic to achieve various connection steps, processing steps, comparison steps, and decision steps.

Claims

1. An apparatus, which is an ion generation system, comprising: a wall defining a boundary of a vacuum space and including a first side inside the vacuum space and a second side outside the vacuum space; a first plate disposed on the first side of the wall and including a first magnet; a second plate disposed on the second side of the wall and including a second magnet; and a motor mechanically coupled to the second plate and configured to drive rotation of the second plate. The apparatus further includes: the second magnet exerts an attractive force on the first magnet, causing the first plate to rotate in response to rotation of the second plate.

2. The apparatus according to claim 1, wherein the attractive force enables heat transfer from the first plate to the second plate by bringing the first plate into thermal contact with the wall and bringing the second plate into thermal contact with the wall.

3. The apparatus according to claim 1, further comprising a cooling coil in thermal contact with the second plate.

4. The apparatus according to claim 1, further comprising a shaft coupled to the wall and having a first end on the first side of the wall and a second end on the second side of the wall, wherein the first plate is mounted on the first end of the shaft and the second plate is mounted on the second end of the shaft.

5. The apparatus according to claim 4, wherein the second plate is held on the shaft by the attractive force.

6. The apparatus according to claim 4, further comprising an O-ring disposed around the shaft by the wall, wherein the shaft and the O-ring are stationary with respect to the wall during rotation of the first plate and the second plate.

7. The apparatus according to claim 1, wherein the first plate and the second plate have the same size and the same shape.

8. The apparatus according to claim 7, wherein the same shape is circular.

9. The apparatus according to claim 1, wherein the first plate further includes a plurality of additional first magnets, the second plate further includes a plurality of additional second magnets, the first magnet and the plurality of additional first magnets are spaced apart from each other and are disposed at a distance from the rotation axis of the first plate, and the second magnet and the plurality of additional second magnets are spaced apart from each other and are disposed at a distance from the rotation axis of the second plate.

10. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The first plate slides along the first side surface of the wall during the rotation of the first plate, and the second plate slides along the second side surface of the wall during the rotation of the second plate. The apparatus according to claim 1.

11. A fluoropolymer-based dry lubricant disposed between the first plate and the first side surface of the wall to reduce friction therebetween The apparatus according to claim 9, further comprising

12. The apparatus according to claim 1, further comprising a target attached to the first plate, the target being configured to capture particles from an ion beam incident thereon.

13. The apparatus according to claim 12, wherein the rotation of the first plate changes the area of the target exposed to the ion beam.

14. An ion beam generator configured to generate the ion beam within the vacuum space and direct the ion beam toward the target The apparatus according to claim 12, further comprising

15. Providing an ion beam incident on a target within a vacuum chamber, Rotating the target by driving rotation of an external plate including an external magnet outside the vacuum chamber and transmitting the rotation of the external plate to an internal plate within the vacuum chamber via an attractive force between the external magnet and an internal magnet of the internal plate, wherein the target is attached to the internal plate. A method comprising

16. The method according to claim 15, further comprising transferring heat from the target to the external plate through the internal plate and the wall of the vacuum chamber.

17. The method according to claim 16, further comprising operating a refrigeration cycle to cool the external plate.

18. The method according to claim 15, wherein driving the rotation of the external plate includes operating a stepping motor coupled to the external plate.

19. When the target is rotated, the area of the target exposed to the ion beam increases due to misalignment of the ion beam with respect to the axis of rotation of the target. The method according to claim 16. ​

20. A wall that defines a boundary of a vacuum space and includes a first side inside the vacuum space and a second side outside the vacuum space, A first plate disposed on the first side of the wall and including a first magnet, A second plate disposed on the second side of the wall and including a second magnet, and A motor mechanically coupled to the second plate and configured to drive rotation of the second plate Including, The second magnet exerts an attractive force on the first magnet, which rotates the first plate in response to rotation of the second plate, and The attractive force is By bringing the first plate into thermal contact with the wall and bringing the second plate into thermal contact with the wall, Enables heat transfer from the first plate to the second plate, Device.

21. A wall that defines a boundary of a vacuum space and includes a first side inside the vacuum space and a second side outside the vacuum space, A first plate disposed on the first side of the wall and including a first magnet, A second plate disposed on the second side of the wall and including a second magnet, A motor mechanically coupled to the second plate and configured to drive rotation of the second plate, and A cooling coil in thermal contact with the second plate Including, The second magnet exerts an attractive force on the first magnet, which rotates the first plate in response to rotation of the second plate, Device.

22. A wall that defines a boundary of a vacuum space and includes a first side inside the vacuum space and a second side outside the vacuum space, A first plate disposed on the first side of the wall and including a first magnet, A second plate disposed on the second side of the wall and including a second magnet, A motor mechanically coupled to the second plate and configured to drive rotation of the second plate, and A shaft coupled to the wall and having a first end on the first side of the wall and a second end on the second side of the wall Including, The second magnet exerts an attractive force on the first magnet, which rotates the first plate in response to rotation of the second plate, The first plate is supported on the first end of the shaft, and The second plate is supported on the second end of the shaft, Device.

23. The device according to claim 22, wherein the second plate is held on the shaft by the attractive force.

24. An O-ring disposed around the shaft by the wall further comprising, During rotation of the first plate and the second plate, the shaft and the O-ring are stationary with respect to the wall, The device according to claim 22.

25. A wall defining a boundary of a vacuum space and including a first side inside the vacuum space and a second side outside the vacuum space, A first plate disposed on the first side of the wall and including a first magnet, A second plate disposed on the second side of the wall and including a second magnet, A motor mechanically coupled to the second plate and configured to drive rotation of the second plate, and A target attached to the first plate including, The second magnet exerts an attractive force on the first magnet, which rotates the first plate in response to rotation of the second plate, and The target is configured to capture particles from an ion beam incident thereon, device.

26. The device according to claim 25, wherein the area of the target exposed to the ion beam changes due to the rotation of the first plate.

27. An ion beam generator configured to generate the ion beam within the vacuum space and direct the ion beam toward the target further comprising, The device according to claim 25.

Images