Thermostat for an atomic clock and related method

Abstract

The present disclosure relates to an oven for an atomic clock, which can include a main body including a cavity within the main body. A plurality of heating elements can be distributed around the main body, each of the plurality of heating elements including a coil of electrically resistive material. The plurality of heating elements can be arranged such that the far fields of magnetic fields of opposite polarity induced by the respective coils of the heating elements overlap.

Description

[0001] Cross-reference to related applications

[0002] This application is a national phase entry of International Patent Application PCT / US2020 / 070677, filed on October 20, 2020, designating the People's Republic of China, and published in English on February 3, 2022 as International Patent Publication WO 2022 / 025972 A1. This application claims the benefit of U.S. Provisional Patent Application Serial No. 62 / 706,080, filed on August 11, 2020, entitled "OVENS FOR ATOMIC CLOCKS AND RELATED METHODS", the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This disclosure relates generally to thermostats for atomic clocks. More specifically, the embodiments disclosed herein relate to thermostats for atomic clocks and methods of manufacturing and using such thermostats, which can achieve high temperatures while reducing the net induced magnetic field at the resonator of the atomic clock, particularly the net induced far field. Background Technology

[0004] Atomic clocks typically measure electromagnetic signals emitted or absorbed by electrons in atoms when the energy levels of those electrons / atoms change. To vaporize the atoms and propel them into the relevant detection region of the atomic clock, a thermostat heats the material within the target cavity. The target cavity, along with other parts of the atomic clock, can be kept under near-vacuum conditions to reduce the possibility of atmospheric interaction with the thermostat's materials or components. Summary of the Invention

[0005] In some embodiments, a thermostat for an atomic clock may include: a body comprising a cavity within the body; and a plurality of heating elements distributed around the body. Each of the plurality of heating elements may include a coil of resistive material. The arrangement of the plurality of heating elements may such that the far-field superposition of magnetic fields of opposite polarities induced by the respective operating coils of the heating elements.

[0006] In some embodiments, a method of fabricating a thermostat for an atomic clock may involve positioning a heating element around a body comprising a cavity within the body. The heating element may comprise coils of resistive material. Interleaved coils in the coils, configured to generate magnetic fields of opposite polarities, may be positioned to control the magnitude of the magnetic field that can be induced by the coils.

[0007] In some embodiments, the method of using a thermostat for an atomic clock may involve heating a material within a cavity of the body using heating elements distributed around the body. The heating elements may include coils of resistive material. The magnitude of the magnetic field induced by the coils of the heating elements can be controlled by using adjacent heating elements to generate magnetic fields of opposite polarities. Attached Figure Description

[0008] Although this disclosure concludes with claims that specifically point out and clearly claim protection for particular embodiments, the various features and advantages of embodiments within the scope of this disclosure can be more readily identified by the following description when read in conjunction with the accompanying drawings. In the drawings:

[0009] Figure 1 An exploded side perspective view of the thermostat according to this disclosure;

[0010] Figure 2 for Figure 1 A top view of the thermostat, in which some external parts have been removed to allow a view of the internal parts;

[0011] Figure 3 for Figure 1 A cross-sectional side view of the thermostat;

[0012] Figure 4 To depict assembly Figure 1 A flowchart illustrating an exemplary method for using a thermostat;

[0013] Figure 5 To show Figure 1 The circuit diagram showing how the heating elements of the thermostat can be electrically connected to each other and to the power supply.

[0014] Figure 6 A partial cross-sectional top perspective view of another embodiment of a heating element that can be used in a thermostat according to this disclosure;

[0015] Figure 7 for Figure 6 A cross-sectional side perspective view of the heating element; and

[0016] Figure 8 The diagram below illustrates an atomic clock. Detailed Implementation

[0017] The embodiments disclosed herein generally relate to thermostats for atomic clocks and methods of manufacturing and using such thermostats, which can achieve high temperatures while mitigating undesirable effects of the net induced magnetic field near the resonator of the atomic clock, such as frequency shifts in atomic transitions. In other words, the sum of the far-field effects of the magnetic field of the heater of the thermostat can be ignored or canceled out, and thus other undesirable fields at the resonator of the atomic clock can be reduced. For example, the heating elements of the thermostat can be arranged such that the far fields of magnetic fields of opposite polarities induced by the respective operating coils of the heating elements can overlap. More specifically, the invention discloses embodiments of thermostats for atomic clocks in which the coils of the heating elements are positioned in pairs, the coils being configured to generate magnetic fields of opposite polarities, such that the magnitude of the magnetic field (particularly the far field) generated at the resonator of the atomic clock is controlled (e.g., weakened, reduced, substantially eliminated). In some embodiments, the net magnitude of the magnetic field (particularly the far field) induced by the coils at the resonator of the atomic clock can be less than the magnitude of any one of the magnetic fields induced by the respective heating elements. In some implementations, the net reduction in the magnitude of the induced magnetic field in the resonator can offset (i.e., may not induce) changes in material properties (such as, for example, the energy levels of atoms) that could be induced by the far field of the magnetic field, changes that could otherwise be induced in one or more components of the associated atomic clock (e.g., in the resonator of the atomic clock) or in the material itself. For example, each heating element may include two coils: an inner coil and an outer coil concentrically positioned around the inner coil, each coil configured to generate magnetic fields of opposite polarities (e.g., similar magnetic poles pointing in substantially opposite directions). Alternatively, each heating element may include a single coil, and each heating element may be configured to generate a magnetic field having a polarity opposite to that of the magnetic field of each adjacent heating element.

[0018] As used herein, the terms “substantially” and “about” with respect to a given parameter, property, or condition mean and include the degree to which a given parameter, property, or condition satisfies the degree of variance (e.g., within acceptable manufacturing tolerances) as would be understood by one of ordinary skill in the art. For example, a parameter substantially or about a specified value could be at least about 90%, at least about 95%, at least about 99%, or even at least about 99.9% of the specified value.

[0019] As used in this article, “each” means some or all. As used in this article, “every single” means all.

[0020] The illustrations presented in this disclosure are not intended to be actual views of any particular thermostat, circuit, heating element, atomic clock, or component thereof, but are merely idealized representations for illustrating exemplary embodiments. Therefore, the figures are not necessarily drawn to scale.

[0021] Figure 1 An exploded side perspective view of the thermostat 100 according to this disclosure. Figure 2 for Figure 1 A top view of the thermostat 100, in which some external parts have been removed to allow the internal parts to be seen. Figure 3 for Figure 1 A cross-sectional side view of the thermostat 100; in conjunction with reference Figure 1 , Figure 2 and Figure 3 The thermostat 100 may include a body 102 whose dimensions, shape, position, and configuration are set to receive material (not shown) to be heated within the thermostat 100. For example, the body 102 may define a cavity 104 within the body 102, and the material may be positioned within the cavity 104 to heat the material for subsequent use in an atomic clock. The cavity 104 may also be alternatively referred to herein as a "chamber". When the thermostat 100 is assembled, heating elements 106 may be distributed around the body 102 and may be positioned and configured to heat the material in the cavity 104. Heating elements 106 may typically be configured as resistance heating elements and may include a coil 108 of resistive material. The coil 108 may be configured to generate heat in response to an electric current flowing through the coil 108.

[0022] The positioning, electrical connection, and operating configuration of the heating element 106 and the coil 108 can cause the coil 108 to generate a magnetic field of opposite polarity in order to control the magnitude of the magnetic field induced by the coil 108 in and around the thermostat 100 (such as, for example, within the resonator of an atomic clock including the thermostat 100). More specifically, the heating element 106 can be arranged such that the far fields of the magnetic fields of opposite polarity induced by the corresponding operating coil 108 of the heating element 106 can overlap. As a specific, non-limiting example, each heating element 106 can be at least substantially similar to each other (e.g., in design, rated power, heat output per unit time, and / or magnitude), and providing an even number of heating elements 106 that are appropriately spaced and positioned can ensure that for each heating element 106 there is another heating element 106 to generate a far field of a magnetic field of opposite polarity, at least substantially canceling out the net effect of the far field. The heating element 106 can also be characterized as a "cylinder heater". Figures 1 to 3In one embodiment, for example, heating elements 106, each having a single coil 108, are distributed around the body 102 such that adjacent heating elements 106 can be configured to generate magnetic fields with opposite polarities. The opposite polarities can at least substantially cancel out the effects of the magnetic fields, at least in certain locations, such as, for example, in the far field of the magnetic field near the resonator of an atomic clock. The heating elements 106 are distributed at equal radial distances from the longitudinal axis 107 defined by the body 102, wherein there is an equidistant radial spacing between each heating element 106.

[0023] To facilitate minimizing the net effect of the magnetic field generated by the heating elements 106, the total number of heating elements 106 in the thermostat 100 can be, for example, even, in embodiments where each heating element 106 comprises only a single coil 108 or a group of coils 108 (all coils carrying current in the same clockwise direction 212 or counterclockwise direction 214). More specifically, the total number of heating elements 106 in the thermostat 100 can be between about 6 and about 10 (e.g., about 8), which ensures that the heating elements 106, both as an arrangement and as a group, can generate enough heat to vaporize the object material. Having an even number of heating elements 106 ensures that for each heating element 106 configured to generate a magnetic field of a given polarity, there can be another heating element 106 configured to generate a magnetic field of opposite polarity, particularly when each heating element 106 comprises only a single coil 108 or a group of coils 108 (all coils carrying current in the same clockwise direction 212 or counterclockwise direction 214).

[0024] In some embodiments, each heating element 106 can be configured to generate a magnetic field having the opposite polarity to each circumferentially adjacent heating element 106. For example, and particularly emphasized Figure 2 Each of the heating elements 106 located at the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions can be configured to generate a net induced magnetic field with a first polarity, and those heating elements 106 located between the 1 o'clock and 2 o'clock positions, between the 4 o'clock and 5 o'clock positions, between the 7 o'clock and 8 o'clock positions, and between the 10 o'clock and 11 o'clock positions can be configured to generate a net induced magnetic field with a second opposite polarity. Arranging the heating elements 106 configured to generate magnetic fields of opposite polarities adjacent to each other in an alternating pattern facilitates reducing the combined, experienced magnitude of the induced magnetic field (particularly the induced far field) in the associated atomic clock (e.g., in its resonator).

[0025] In order to generate magnetic fields with opposite polarities, the coils 108 of adjacent heating elements 106 can, for example, be configured to carry current in opposite clockwise or counterclockwise directions. For example, and specifically referring to Figure 2 The coil 108 of each of the heating elements 106 located at the 12 o'clock, 3 o'clock, 6 o'clock, and 9 o'clock positions can be configured to carry current in one of the clockwise or counterclockwise directions, and the coils 108 of those heating elements 106 located between the 1 o'clock and 2 o'clock positions, between the 4 o'clock and 5 o'clock positions, between the 7 o'clock and 8 o'clock positions, and between the 10 o'clock and 11 o'clock positions can be configured to carry current in the other of the clockwise or counterclockwise directions 212 or 214 directions. Arranging the coils 108 of the heating elements 106 configured to carry current in the opposite clockwise or counterclockwise directions 212 or 214 in an alternating pattern can facilitate a reduction in the combined, experienced magnitude of the induced magnetic field in the area near and outside the thermostat 100, especially when the coil 108 of each heating element 106 is configured to carry current in only one clockwise or counterclockwise direction 212 or 214 direction. In some embodiments, different complementary pairs of coils 108 may be formed by a single wire wound from the bottom (near the base 120) of a first tube 202 (such as tube 202a) toward the top of the first tube 202 to form a first set of coils 108 of the first heating element 106, and then wound from the top (away from the base 120) of a second adjacent tube 202 (such as tube 202b) toward the bottom of the second tube 202 to form a second set of coils 108 of the second adjacent heating element 106.

[0026] In some embodiments, each heating element 106 may include a tube 202 of electrically insulating material (such a tube has a cross-section consisting of...) Figure 2 (As shown), the coil 108 of the corresponding heating element 106 can be positioned around the tube. For example, wires can be wound around the tube 202, i.e., around the outer surface of the tube 202, to form the coil 108, and the tube 202 can include an electrically insulating material to prevent undesirable electrical connections from forming between the coils 108. Each heating element 106 may also include a support 110 of, for example, a conductive material, extending from below the tube 202, through the tube 202, to connect to the coil 108. More specifically, each support 110 may include a wire having a smaller specification than the wire forming the coil 108, i.e., a larger diameter, and the support 110 can extend through a channel 204 within the tube 202 to support the tube 202 and the associated coil 108 in a selected location and orientation, and the support 110 can be electrically connected to the wire forming the coil 108 near the upper part of the heating element 106. The end of the support member 110, positioned on the side of the base 120 opposite to the heating element 106, can be electrically connected to the power supply 502 (see...). Figure 5 ).

[0027] The thermostat 100 may include a sheath 112 of electrically insulating material that at least partially surrounds the coil 108 of each heating element in the heating elements 106. The sheath 112 may also be referred to herein as a “casing”. The sheath 112 may be configured to resist heat generated by the heating elements 106 from being transferred to the outside of the thermostat 100, reduce the exposure of components and materials located within the thermostat 100 to unwanted radiation, and maintain the relative positioning and orientation of certain components (such as, for example, the body 102, the heating elements 106, or both) within the thermostat 100. For example, when the thermostat 100 is assembled, the sheath 112 may be positioned radially outward from the body 102, may typically be configured as a sleeve or tube, and may be positioned around the heating elements 106 to form the radially outer surface of the thermostat 100 around the heating elements 106. More specifically, the shroud 112 may define a keyway 114, which is typically shaped to form a repeating pattern of a first, larger central cylindrical gap in which the body 102 can be located when the thermostat 100 is assembled, and a second, smaller peripheral cylindrical gap intersecting the first gap in which the corresponding heating element 106 can be located when the thermostat 100 is assembled. The keyway 114 may have a clearance fit relative to the heating element 106 so that the shroud 112 can be introduced around the heating element 106 and the body 102.

[0028] In some embodiments, the connecting end 206 (which may also be referred to as a "terminal") of the wire forming the coil 108 may extend between the housing 112 and the base 120 to the outside of the housing 112 for connection to the power supply 502 (see [link to relevant documentation]). Figure 5 For example, the connection end 206 of a heating element 106 can be connected to the positive terminal of a power supply 502 (see...). Figure 5 Furthermore, the connection end 206 of the heating element 106 adjacent to the heating element highlighted above can be connected to the negative terminal of the power supply 502 (see...). Figure 5 The coil 108 of the given heating element 106 and the support 110 can be connected to the top of the tube 202, as shown. Figure 2 As best seen, the wires forming the coil 108 of a heating element 106 can extend continuously to form coils of adjacent heating elements 106, thus forming a closed loop. Therefore, the current flowing through the two heating elements 106 will be the same amount, but in opposite directions. The net effect is the cancellation of the magnetic field in the far field. In the event of damage to one coil, the current will stop flowing through both coils 108, and the far-field magnetic field will remain cancelled. In power supply 502 (see...) Figure 5 In embodiments configured to supply alternating current to heating element 106, alternating current that is 180° out of phase with each other can be supplied to adjacent heating elements 106, which can achieve the same effect.

[0029] refer to Figure 1 and Figure 3 In some embodiments, the thermostat 100 may include a gasket 116 of electrically insulating material covering the shroud 112. For example, the gasket 116 may form a cap positioned above a keyway 114 of the shroud 112 to at least partially enclose the body 102 and the heating element 106 within the shroud 112. More specifically, the gasket 116 may be formed as a disk having the same diameter as the outer diameter of the shroud 112 and may include an opening 118 to facilitate the conveyance of the material to be heated through the gasket 116 and into the cavity 104 of the body 102, and to facilitate the movement of excited atoms from the cavity 104 out of the thermostat 100. Optionally, it may include one or more recesses 302 on the underside of the gasket 116, the recesses 302 being formed and positioned to receive the uppermost portion of the heating element 106 within the respective recesses 302. The thermostat 100 may also include a base 120 of electrically insulating material positioned beneath the shroud 112. For example, the lower surfaces of the body 102, tube 202, and shield 112 may contact and be supported on the upper surface of the base 120. The base 120 may include a cavity 122 extending through the thickness of the base 120 such that an electrical connector to a heating element 106 (such as support 110) extends through the cavity 122 to the heating element. More specifically, the support 110 may extend from below the base 120, through the corresponding cavity 122, and through the corresponding tube 202, to connect to the associated coil 108 of the corresponding heating element 106.

[0030] The cap 124 may cover the cover 112. For example, the cap 124 may include: a first portion 126 sized, shaped, and configured to extend through an opening 118 in the washer 116; and a second portion 128 sized, shaped, and configured to contact and rest on the upper surface of the washer 116. The first portion 126 of the cap 124 may be secured to the body, such as by means of threaded connections formed in the outer surface of the first portion 126 of the cap 124 and in the inner surface of at least the upper portion of the cavity 104. The cap 124 may clamp the washer 124 and the cover 112 in place by the force generated by the connection between the body 102 and the cap 116, which acts through the contact between the cap 124 and the washer 116 in a direction oriented toward the base 120 from the point of contact between the cap 124 and the washer 116. The cap 124 may include a nozzle 304 extending through the cap 124. The nozzle 304 allows vaporized atoms of the object material to escape from the cavity 104 and the thermostat 100 for use in the atomic clock, while retaining the remaining unvaporized portion of the object material within the cavity 104.

[0031] In some embodiments, the body 102 may also be secured to the base 120. For example, the body 102 may include a protrusion 130 positioned on the end of the body 102 opposite to the opening to the cavity 104, the protrusion 130 extending through an anchoring hole 132 defined in the base 120. The body 102 may be secured to the appropriate position on the base 120 by engaging the protrusion 130 with a connector 134, such as by means of a threaded connection, snap-fit ​​engagement, friction locking, etc.

[0032] Suitable materials for components of thermostat 100 (such as, for example, support 110 and coil 108) typically possess appropriately high electrical resistance, appropriately high melting point, corrosion resistance, and exhibit at least substantially stable properties at the designed operating temperature and pressure. As a specific, non-limiting example, materials for components of thermostat 100 (such as, for example, support 110, coil 108, body 102, and cap 124) may include tantalum, tungsten, or other elements or alloys. Suitable electrical insulating materials for other components of thermostat 100 (such as, for example, tube 202, shield 112, gasket 116, and base 120) typically do not react with the selected material, possess corrosion resistance, and are at least substantially stable at the desired operating temperature and pressure. For example, insulating materials for components of thermostat 100 may include ceramic materials. In some embodiments, the insulating material may be sandblasted to clean the components prior to assembly.

[0033] According to the thermostat (such as) disclosed herein Figure 1 The thermostat 100 enables the use of material in atomic clocks that require higher temperatures to generate properly excited atoms. For example, the thermostat 100 can be configured to heat at least a portion of the cavity 104 to a temperature between about 350°C and about 450°C, thereby exposing the material in the cavity 104 to such temperatures. Such temperatures achievable within the cavity 104 enable the use of material requiring high vaporization temperatures.

[0034] Figure 4 To depict assembly Figure 1 A flowchart illustrating an exemplary method 400 for assembling a thermostat 100 is provided. When assembling the thermostat 100, the body 102 can be placed on a base 120, and a protrusion 130 of the body 102 can be inserted through an anchoring hole 132. A heating element 106 can be positioned around the body 102 as shown in action 402. A connector 134 can engage with the protrusion 130 to secure the body 102 to the base 120, as shown in action 404. A support member 110 can be inserted through a hole 122 in the base 120, and a tube 202 (see...) Figure 2The tubes 202 can be positioned around the portion of the support 110 located on the same side of the base 120 as the body 102. Wires can be wound around the tubes 202 to form coils 108, which can occur before or after placing the tubes 202 around the respective support 110, and the coils 108 can be electrically connected to the support 110. The coils 108 can be positioned and configured to generate magnetic fields of opposite polarity to control the magnitude of the magnetic field induced by the coils 108, such that the far-field superposition of the magnetic fields of opposite polarity induced by the respective coils 108 of the heating element, particularly near the thermostat 100, as shown in action 406. Specifically, an even number of tubes 202 are distributed at equal radial distances from the longitudinal axis 107 defined by the body 102, wherein there is an equidistant radial spacing between each tube in the tubes 202, and adjacent coils 108 wound around the respective tubes 202 are arranged to generate magnetic fields of opposite polarity. A shield 112 can be placed around the heating element 106, a gasket 116 can be positioned to contact the shield 112 above the heating element 106, and a cap 124 can engage with the body 102 to secure the component in place, as shown in action 408.

[0035] The object material can optionally be placed in cavity 104, and the thermostat 100 and the object material can be placed in a chamber that is at least substantially a vacuum (e.g., an ultra-high vacuum suitable for atomic clock applications). The thermostat according to this disclosure enables the use of object materials with higher activation temperatures.

[0036] Figure 5 To show Figure 1 The circuit diagram shows how the heating elements 106 of the thermostat 100 can be electrically connected to each other and to a power source. For example, the heating elements 106 can typically be grouped into complementary pairs extending around the circumference of the thermostat 100. For convenience, Figure 5 Each heating element 106 shown is labeled in a clockwise order around the body 102, starting with the topmost heating element 106 (i.e., the heating element 106 located at the 12 o'clock position), as... Figure 2 As shown. Each heating element 106 can be connected in series to one adjacent heating element 106 and in parallel to another adjacent heating element 106. For example, in Figure 5Heating element 106, labeled R1, is connected in series with heating element 106, labeled R2, and in parallel with heating element 106, labeled R8. More specifically, each heating element 106 may be connected in series with one of the heating elements 106 positioned circumferentially adjacent to it, and in parallel with each of the other heating elements 106. As a specific, non-limiting example, different pairs of heating elements 106 may be connected in series with each other, and each pair of heating elements 106 may be connected in parallel with each of the other pairs of heating elements 106. With this configuration, each heating element 106 can be connected to a power supply 502 sufficient to power the heating elements 106.

[0037] Figure 6 A partial cross-sectional top perspective view of another embodiment of the heating element 600 that can be used in a thermostat according to this disclosure. Figure 7 for Figure 6 A cross-sectional side perspective view of the heating element 600. (Assembled reference) Figure 6 and Figure 7 According to this disclosure, certain heating elements 600 may include coils 602 and 604, which are positioned and configured to at least substantially counteract at least a portion of the magnetic field generated by coils 602 and 604, more specifically, the magnetic field at the resonator of an atomic clock outside the thermostat 100 (see...). Figure 8 The heating element 600 is negligible. Such a heating element 600 can exist independently of pairing within the atomic clock and around the thermostat 100 (such as, for example, within the resonator) (see...). Figures 1 to 3 This achieves a low detectable magnetic field, particularly in the far field. For example, the heating element 600 may include a first coil 602 (or coil group) of resistive material positioned around an electrically insulating tube 603 (i.e., around the outer surface of the electrically insulating tube 603) and a second coil 604 (or coil group) positioned within the tube 603. In such embodiments, a support 601 may be formed of an electrically insulating material, and the support 601 may extend through the second coil 604 (or coil group). In other words, the second coil 604 (or coil group) may be inserted between the support 601 and the interior of the tube 603. To reduce the strength of the detectable magnetic field that can be generated by the heating element 600, the first coil 602 may be configured to carry current in a clockwise direction 612 or a counterclockwise direction 614, opposite to the direction in which the current is configured to be carried by the second coil 604.

[0038] Figure 8This is a schematic diagram of an exemplary atomic clock 800 including a thermostat 100 according to the present disclosure. Vaporized atoms of the object material generated by the thermostat 100 can exit through a nozzle 304 and be transferred to a resonator 804. The resonator 804 may include an inspection region therein that can guide the vaporized atoms of the object material, and one or more emitters (e.g., laser 806, microwave 808) may be configured to direct energy of known type and intensity toward the inspection region. Detector 802 may include a sensor configured to detect one or more properties of the vaporized atoms of the object material in response to the emitted energy. For example, the sensor of detector 802 may be oriented toward the inspection region and configured to detect transitions of electrons in the object material between energy levels, such as those measured in the change of signal intensity relative to the frequency of microwave 808, in response to energy from a first emitter (e.g., from laser 806). One or more signals representing the properties measured by detector 802 may be provided as feedback to oscillator 810. Oscillator 810 can be used to generate clock output 812, which can be used as a clock signal itself or to verify or synchronize another clock signal. In other words, oscillator 810 can generate clock output 812 in response to a frequency change from a second transmitter (e.g., microwave 808) (as detected by a corresponding change in energy from a first transmitter (e.g., laser 806), the clock output being timed to a frequency corresponding to the rate of transitions between energy levels of the atoms in the target material. Oscillator 810 can also be used to generate / synthesize microwave 808.

[0039] Such atomic clocks 800 are particularly useful for generating, verifying, or synchronizing highly accurate clock signals and / or in extreme environmental conditions (e.g., near-vacuum, low gravity or microgravity, near-Earth orbit, and / or space). The atomic clock 800 according to this disclosure can be applied in the aerospace industry (e.g., to control clock signals in satellites and spacecraft), telecommunications and banking (e.g., to verify or set clock signals for relevant computing systems), and standard setting scenarios (e.g., to establish timing for relevant standards). By reducing the net induced magnetic field generated by the coils 108 or 602 and 204 of the thermostat 100, particularly the far field at the resonator 804 of the atomic clock 800, the construction and operation of the thermostat 100 can reduce the likelihood that any electronic signals received at or generated therefrom at the resonator 804 may be affected (e.g., distorted) by the current induced by the net magnetic field or variations therein.

[0040] The thermostat for atomic clocks according to this disclosure enables the use of materials with high activation temperatures. This property allows for deployment in applications involving long-term, high-reliability use, even under harsh environmental conditions. Reducing the induced magnetic field can reduce the likelihood of clock frequency shift, and also reduce the possibility that the induced magnetic field (particularly the net induced far field at the resonator of the atomic clock) might interfere with other sensitive electronic components of the atomic clock.

[0041] In addition, non-restrictive embodiments within the scope of this disclosure include:

[0042] Implementation Scheme 1: A thermostat for an atomic clock, the thermostat comprising: a body, the body including a cavity within the body; and a plurality of heating elements distributed around the body, each of the plurality of heating elements including a coil of resistive material, the arrangement of the plurality of heating elements being such that the far-field superposition of magnetic fields of opposite polarities induced by the respective coils of the heating elements is achieved.

[0043] Implementation Scheme 2: The thermostat according to Implementation Scheme 1, wherein the plurality of heating elements includes two complementary heating elements configured to generate magnetic fields of opposite polarities.

[0044] Implementation Scheme 3: According to the thermostat described in Implementation Scheme 1, each of the plurality of heating elements is connected in series to an adjacent heating element among the plurality of heating elements, and is connected in parallel to another adjacent heating element among the plurality of heating elements.

[0045] Implementation Scheme 4: The thermostat according to Implementation Scheme 1, wherein at least one pair of heating elements of the plurality of heating elements are connected in series with each other and in parallel with each other heating element of the plurality of heating elements.

[0046] Implementation Scheme 5: The thermostat according to any one of Implementation Schemes 1 to 4, wherein the plurality of heating elements comprises an even number of heating elements.

[0047] Implementation Scheme 6: A thermostat according to any one of Implementation Schemes 1 to 5, wherein each of the plurality of heating elements is configured to generate a magnetic field having opposite polarity to the magnetic field generated by each circumferentially adjacent heating element.

[0048] Implementation Scheme 7: A thermostat according to any one of Implementation Schemes 1 to 6, wherein the coils of adjacent heating elements are configured to carry current in opposite clockwise or counterclockwise directions.

[0049] Implementation Scheme 8: A thermostat according to any one of Implementation Schemes 1 to 7, wherein each of the plurality of heating elements comprises a tube of electrically insulating material and a support of conductive material, the respective coil of the heating element is positioned around the tube, and the support extends from below the tube through the tube to connect to the respective coil.

[0050] Implementation Scheme 9: A thermostat according to any one of Implementation Schemes 1 to 7, wherein each of the plurality of heating elements comprises a tube of electrically insulating material, a first coil of the respective heating element is positioned around the tube, a second coil of the respective heating element is positioned inside the tube, and a support extends through the tube and through the second coil.

[0051] Implementation Scheme 10: The thermostat according to Implementation Scheme 9, wherein the first coil is configured to carry current in a clockwise or counterclockwise direction opposite to the direction in which the current is configured to be carried by the second coil.

[0052] Implementation Scheme 11: The thermostat according to any one of Implementation Schemes 1 to 10 further includes a cover of electrically insulating material, the cover at least partially surrounding the coil of each of the plurality of heating elements, the cover being positioned radially outward from the body.

[0053] Implementation Scheme 12: The thermostat according to Implementation Scheme 11 further includes a gasket of electrically insulating material covering the cover and a base of electrically insulating material located below the cover, with an electrical connector extending through a cavity in the base to the respective heating element among the plurality of heating elements.

[0054] Implementation Scheme 13: The thermostat according to Implementation Scheme 12 further includes a cap-shaped member covering the protective cover, the cap-shaped member being fixed to the main body, the cap-shaped member clamping the gasket and the protective cover in an appropriate position.

[0055] Implementation Scheme 14: The thermostat according to Implementation Scheme 12 or Implementation Scheme 13, wherein the main body is fixed to the base.

[0056] Implementation Scheme 15: A method of manufacturing a thermostat for an atomic clock, the method comprising: positioning a heating element around a body including a cavity within the body, the heating element including a coil of resistive material; and positioning interleaved coils in the coil to generate magnetic fields of opposite polarities to control the magnitude of the magnetic field that can be induced by the coil.

[0057] Implementation Scheme 16: The method according to Implementation Scheme 15 further includes connecting each heating element in series to one of the adjacent heating elements and in parallel to another of the adjacent heating elements.

[0058] Implementation Scheme 17: The method according to Implementation Scheme 15 further includes connecting at least one pair of said heating elements in series with each other and in parallel with each other heating element.

[0059] Implementation Scheme 18: A method of using a thermostat for an atomic clock, the method comprising: heating a material within a cavity of a body using heating elements distributed around a body, the heating elements comprising coils of resistive material; and controlling the magnitude of a magnetic field induced by the coils of the heating elements by using adjacent heating elements to generate magnetic fields of opposite polarities.

[0060] Implementation Scheme 19: The method according to Implementation Scheme 18, wherein controlling the magnitude of the magnetic field that can be induced by the coil includes: guiding current through the first coil of the first heating element in a clockwise or counterclockwise direction; and guiding current through the second coil of the second heating element in the opposite direction.

[0061] Implementation Scheme 20: The method according to Implementation Scheme 18 or Implementation Scheme 19, wherein controlling the magnitude of the magnetic field induced by the coil comprises: directing current to adjacent pairs of the heating elements connected in series with each other; and directing current in parallel to another adjacent heating element among the heating elements. While certain exemplary embodiments have been described in conjunction with the accompanying drawings, those skilled in the art will recognize and understand that the scope of this disclosure is not limited to those embodiments explicitly shown and described herein. Rather, many additions, deletions, and modifications can be made to the embodiments described in this disclosure to produce embodiments within the scope of this disclosure, such as those specifically claimed, including legal equivalents. Furthermore, features from one disclosed embodiment may be combined with features from another disclosed embodiment while still being included within the scope of this disclosure.

Claims

1. A thermostat for an atomic clock, the thermostat comprising: The main body includes a cavity within the main body; A plurality of heating elements are distributed around the body, each of the plurality of heating elements comprising a coil of resistive material, the arrangement of the plurality of heating elements being such that for each coil configured to generate a first-order magnetic field, the heating element includes another coil configured to generate an opposite second-order magnetic field; and A protective cover made of electrically insulating material, the cover being configured as a sleeve or tube and placed around the plurality of heating elements, the cover being positioned radially outward from the body.

2. The thermostat of claim 1, wherein the plurality of heating elements comprises two complementary heating elements configured to generate magnetic fields of opposite polarities.

3. The thermostat according to claim 1, wherein each of the plurality of heating elements is connected in series to an adjacent heating element among the plurality of heating elements, and is connected in parallel to another adjacent heating element among the plurality of heating elements.

4. The thermostat of claim 1, wherein at least one pair of heating elements of the plurality of heating elements is connected in series with each other and in parallel with each other heating element of the plurality of heating elements.

5. The thermostat according to claim 1, wherein the plurality of heating elements comprises an even number of heating elements.

6. The thermostat of claim 1, wherein each of the plurality of heating elements is configured to generate a magnetic field having opposite polarity to the magnetic field generated by each circumferentially adjacent heating element.

7. The thermostat of claim 1, wherein the coils of adjacent heating elements are configured to carry current in opposite clockwise or counterclockwise directions.

8. The thermostat of claim 1, wherein each of the plurality of heating elements comprises a tube of electrically insulating material and a support of conductive material, the respective coil of the heating element is positioned around the tube, and the support extends from below the tube through the tube to connect to the respective coil.

9. The thermostat according to any one of claims 1 to 8, wherein each of the plurality of heating elements comprises a tube of electrically insulating material, a first coil of the respective heating element is positioned around the tube, a second coil of the respective heating element is positioned inside the tube, and a support extends through the tube and through the second coil.

10. The thermostat of claim 9, wherein the first coil is configured to carry current in a clockwise or counterclockwise direction opposite to the direction in which the current is configured to be carried by the second coil.

11. The thermostat according to any one of claims 1 to 8, wherein the protective cover comprises a ceramic material.

12. The thermostat according to any one of claims 1 to 8 and 11, further comprising a gasket of electrically insulating material covering the cover and a base of electrically insulating material located below the cover, wherein an electrical connector to the heating element extends through a cavity in the base to the respective heating element among the plurality of heating elements.

13. The thermostat of claim 12 further includes a cap-shaped member covering the cover, the cap-shaped member being fixed to the body, the cap-shaped member clamping the gasket and the cover in place.

14. The thermostat of claim 12, wherein the body is fixed to the base.

15. A method for manufacturing a thermostat for an atomic clock, the method comprising: A heating element is positioned around a body, the body including a cavity within the body, and the heating element including a coil of resistive material; Positioning the interleaved coils in the coil to generate magnetic fields of opposite polarities, thereby controlling the magnitude of the magnetic field that can be induced by the coil; as well as A protective cover for placing electrical insulating material, the cover being configured as a sleeve or tube surrounding the heating element, the cover being positioned radially outward from the body.

16. The method of claim 15, further comprising connecting each heating element in series to one of the adjacent heating elements and in parallel to another of the adjacent heating elements.

17. The method of claim 15, further comprising connecting at least one pair of said heating elements in series with each other and in parallel with each other heating element.

18. A method of using a thermostat for an atomic clock, the method comprising: Materials within the cavity of the body are heated using heating elements distributed around the body, the heating elements including coils of resistive material; The magnitude of the magnetic field that can be induced by the coil of the heating element is controlled by using adjacent heating elements to generate magnetic fields of opposite polarity. as well as A protective cover of electrically insulating material, constructed as a sleeve or tube and placed around the heating element, is used to resist the transfer of heat generated by the heating element to the outside of the thermostat. The protective cover is positioned radially outward from the main body.

19. The method of claim 18, wherein controlling the magnitude of the magnetic field induced by the coil comprises: The current is guided through the first coil of the first heating element in a clockwise or counterclockwise direction; And a second coil that guides current through the second heating element in the opposite direction.

20. The method of claim 18 or claim 19, wherein controlling the magnitude of the magnetic field induced by the coil comprises: Directing current to adjacent pairs of the heating elements that are connected in series with each other; And to guide the current in parallel to another adjacent heating element in the heating element.

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