Cryogen-free high-temperature superconductor undulator structure and method for manufacturing the same

A cryogen-free high-temperature superconductor undulator structure is provided. The superconductor undulator structure includes a magnetic core body and a coil structure. The magnetic core body includes a first and a second half magnetic pole arrays that are vertically aligned, a plurality of first winding cores in the first half magnetic pole array, and a plurality of second winding cores in the second half magnetic pole array. The coil structure is wound on the first winding cores and the second winding cores of the magnetic core body. The coil structure includes a plurality of first superconductor tapes in contact with each of the first winding cores and each of the second winding cores, and a plurality of second superconductor tapes, each of the second superconductor tapes is in contact with two adjacent first superconductor tapes. A method of manufacturing a cryogen-free high-temperature superconductor undulator structure is also provided.

FIELD

The present disclosure relates to a superconductor undulator and a method for manufacturing the same, particularly, the disclosed high-temperature superconductor undulator is free from using cryogen for cooling.

BACKGROUND

A synchrotron light source is a source of electromagnetic radiation (EM) usually produced by a storage ring, for scientific and technical purposes. First observed in synchrotrons, synchrotron light is now produced by storage rings and other specialized particle accelerators, typically accelerating electrons. Once the high-energy electron beam has been generated, it is directed into auxiliary components such as undulators in storage rings and free-electron lasers. These supply the strong alternating magnetic fields perpendicular to the beam which are needed to convert high-energy electrons into photons.

DETAILED DESCRIPTION

In an undulator which used to extract synchrotron radiation from an electron beam in a synchrotron radiation facility, there is provided a pair of magnet arrays disposed parallel to and opposite each other to produce a periodic magnetic field, and by undulating electrons that travel between the pair of magnet arrays at a speed close to that of light, intense synchrotron radiation is generated. The periodic magnetic field can be produced with permanent magnets or electromagnets. That is, in general, magnetic fields is generated by permanent magnets or electromagnetic coils such as superconducting coils, and it is known that a superconducting undulator can provide a greater strength of magnetic field than a permanent undulator. However, the superconducting undulators must be operated under an extremely low temperature so far, for example, they must be operated by using liquid helium as a coolant to maintain an operating temperature at about 4.2K only. Such consideration leads to a need to develop a novel superconductor undulator structure that can be operated under an environment that no liquid helium is needed. Therefore, a high temperature superconductor undulator that no longer depending on the supplement of liquid helium is provided in the present disclosure.

FIG.1illustrates an upper magnetic core body100A and a lower magnetic core body100B of a superconductor undulator module in some embodiments of the present disclosure. The lower magnetic core body100B is in proximity to a bottom of the upper magnetic core body100A and thereby vertically aligns to the upper magnetic core body100A. Accordingly, an electron beam90may pass through the gap between the upper magnetic core body100A and the lower magnetic core body100B. In order to illustrate the structure details of the upper magnetic core body100A and the lower magnetic core body100B,FIGS.2A to2CandFIGS.3A to3Cfurther show the magnetic core bodies utilized in the present disclosure.

Referring toFIG.2A, in some embodiments, a superconductor undulator structure disclosed in the present disclosure includes the upper magnetic core body100A, wherein the upper the magnetic core body100A in the present disclosure is separated into two half arrays. For instance, as shown in the figure, the upper magnetic core body100A may include a first half magnetic pole array101and a second half magnetic pole array102, while the second half magnetic pole array102is vertically aligned to the first half magnetic pole array101. In some embodiments, the first half magnetic pole array101and the second half magnetic pole array102of the upper magnetic core body100A are made of iron or steel.

Since the magnetic core bodies (i.e., the upper magnetic core body100A and the lower magnetic core body100B) are utilized to increase the strength of magnetic field in an electromagnetic coil, the magnetic core body100in some embodiments of the present disclosure further includes a plurality of winding cores for winding the electromagnetic coil thereon. In some embodiments, as the upper magnetic core body100A shown inFIG.2Aand the side views of the pole units81,82therein that further shown inFIGS.2B and2C, the upper magnetic core body100A includes a plurality of first winding cores103in the first half magnetic pole array101and a plurality of second winding cores104in the second half magnetic pole array102. In some embodiments, the first winding cores103and the second winding cores104are employed to provide grooves for wiring, and therefore, the surfaces of the winding cores may not be coplanar with other portions of the magnetic core body100.

For example, as shown inFIG.2B, the first winding core103in the first half magnetic pole array101may have a top surface103A that slightly lower than a top surface101A of the first half magnetic pole array101. Likewise, as shown inFIG.2C, the second winding core104in the second half magnetic pole array102may have a bottom surface104B slightly higher than a bottom surface102B of the second half magnetic pole array102. In contrast, the structure features of other sides of the first winding core103and the second winding core104are different since a metal plate set (will be discussed later inFIG.7A) is disposed between the first half magnetic pole array101and the second half magnetic pole array102. In such embodiments, the first winding core103and the second winding core104are both in contact with the metal plate set, thus there is no height difference between the pole units81or82at the center of the upper magnetic core body100A. Plan surfaces85A and85B may thereby be provided by the pole units81and82, respectively, at the center of the upper magnetic core body100A for entirely contacting the metal plate set.

Referring toFIG.3A, in some embodiments, the superconductor undulator structure in the present disclosure includes the lower magnetic core body100B, wherein the lower magnetic core body100B in the present disclosure is also separated into two half arrays as that in the upper magnetic core body100A. As illustrated in the figure, the lower magnetic core body100B may include a third half magnetic pole array105and a fourth half magnetic pole array106, while the fourth half magnetic pole array106is vertically aligned to the third half magnetic pole array105. In some embodiments, the material of the third half magnetic pole array105and the fourth half magnetic pole array106of the lower magnetic core body100B are identical to that of the upper magnetic core body100A.

In some embodiments, as the lower magnetic core body100B shown inFIG.3Aand the side views of the pole units83,84therein that further illustrated inFIGS.3B and3C, the lower magnetic core body100B includes a plurality of third winding cores107in the third half magnetic pole array105and a plurality of fourth winding cores108in the fourth half magnetic pole array106. In some embodiments, the third winding cores107and the fourth winding cores108are employed to provide grooves for wiring, and therefore the surfaces of the winding cores may not be coplanar with other portions of the magnetic core body.

For example, as shown inFIG.3B, the third winding core107in the third half magnetic pole array105may have a top surface107A that slightly lower than a top surface105A of the third half magnetic pole array105. Likewise, as shown inFIG.3C, the fourth winding core108in the fourth half magnetic pole array106may have a bottom surface108B slightly higher than a bottom surface106B of the fourth half magnetic pole array106. Like the space between the first half magnetic pole array101and the second half magnetic pole array102in the upper magnetic core body100A, the space between the third half magnetic pole array105and the fourth half magnetic pole array106is used to arrange another metal plate set therein. In such embodiments, the third winding cores107and the fourth winding core108are both in contact with the metal plate set and therefore there is no height difference between the pole units83or84at the center of the lower magnetic core body100B. Plan surfaces86A and86B may thereby be provided by the pole units83and84, respectively, at the center of the lower magnetic core body100B for entirely contacting the metal plate set.

Furthermore, in some embodiments, the first winding cores103and the fourth winding cores108are employed to provide starting points when winding a coil structure on the upper magnetic core body100A and the lower magnetic core body100B. To be more detailed, as shown inFIGS.2B and3C, in such embodiments, each of the first winding cores103and each of the fourth winding cores108comprise a semicircle end (i.e.,103C and108C) and a flat end opposite to the semicircle end.

In some embodiments, a coil structure is used to wound on the winding cores of the magnetic core bodies as previously disclosed. As shown inFIGS.4A to4C, a coil structure30is disclosed. The coil structure30may include a plurality of first superconductor tapes301that in contact with a surface of each of the winding cores (e.g., the first and second winding cores103and104), and a plurality of second superconductor tapes302that in contact with two adjacent first superconductor tapes. The coil structure30in the present disclosure includes a tape-shaped or a sheet-shaped structure instead of a wire structure having a circular cross-section or a rectangular cross-section. That is, the coil structure30in the present disclosure has a width that obviously greater than a thickness thereof. In some embodiments, the coil structure30includes superconductor material such as rare-earth barium copper oxide (REBCO). In some embodiments, the coil structure30superconductor tapes include a multilayer structure that at least a REBCO layer is included. In an example, the coil structure30includes a superconductor tape which has the REBCO layer, such superconductor tape has a thickness as about 0.1 mm and a width as about 4.0 mm.

Comparing to low-temperature superconductor material such as niobium-titanium (NbTi), the high-temperature superconductor (HTS) material such as REBCO may exhibit superconductivity at a comparative high temperature, for example, at about 77K. Accordingly, by using the coil structure30which has high-temperature superconductor material, the superconductor undulator module in the present disclosure may free from using cryogens, such as liquid helium.

In other words, the superconductor undulator module in the present disclosure is no longer restricted by liquid helium since the high-temperature condition 25K and the current density are achievable by using a cyro-cooler. However, the superconductor tapes made by REBCO cannot be bent freely, and therefore the superconductor tapes in the present disclosure do not simply wound on the magnetic core body like that by NbTi superconductor wires. To be more precise, as previously shown inFIGS.2A and3A, there are a plurality of winding cores within the half magnetic pole arrays, but a regular superconductor tape cannot be bent for switching among different winding cores. Accordingly, the present disclosure provides a novel approach to overcome the winding issue raised by the physical property of superconductor tapes.

As shown inFIG.4A, in some embodiments, the first superconductor tape301is employed as a primary portion in the winding, thus the first superconductor tapes301may have a comparatively long length and a width W1which is slightly smaller than to the width of the winding core. On the other hand, like the embodiment shown inFIGS.4B and4C, the second superconductor tape302is employed as a bridging portion and thus it may have a comparatively short length within a bridging region and a width W2at least greater than two times of the width W1of the first superconductor tape301.

In some embodiments, the second superconductor tape302may be called a superconductor bridging plate. In some embodiments, the second superconductor tape302can be divided into a plurality of inner second superconductor tape and a plurality of outer second superconductor tape depends on the location of the second superconductor tape302. The categorization of second superconductor tape302will be discussed later.

In some embodiments, each of the second superconductor tape302is in contact with two first superconductor tapes301that belong to two adjacent magnet coils, for example, as illustrated inFIG.4C, the magnet coils C1, C2, C3, . . . and Cncan be electrically connected by the second superconductor tapes302and therefore a continuous coil structure is substantially formed. In fact, the second superconductor tape302is employed as a termination joint to electrically connect to the first superconductor tapes301of adjacent magnet coils, which means the first superconductor tapes301reverses in direction upon passage through the joint, and the plurality of first superconductor tapes301are entirely parallel to each other. Generally, the first superconductor tapes301are jointed to a number of the second superconductor tapes302(e.g., a plurality of inner superconductor tape portions33) prior to being winding on the winding cores. As shown inFIG.4C, in some embodiments, each of the first superconductor tapes301in proximity to two sides of the coil structure30may have a connecting section301A free from in contact with the second superconductor tapes302. The outer section301A of the first superconductor tapes301may connect to a current source such as a power supply or other electronic devices. Furthermore, the coil structure30may further be divided into the inner superconductor tape portion33and an outer superconductor tape portion34, wherein the inner superconductor tape portion33is the portion that mainly be wounded along the first, second, third, or the fourth winding cores103,104,106,107, whereas the outer superconductor tape portion34is the portion that mainly be placed at the sides of the upper magnetic core body100A and the lower magnetic core body100B.

As previously mentioned, the superconductor tapes made of REBCO cannot be bent freely. Therefore, in order to wound the first superconductor tapes301on the winding cores, the structures of the winding cores are designed to fit the physical property of the superconductor tapes. Referring toFIGS.2A and2Bagain, the first winding core103includes the semicircle end103C. In some embodiments, the semicircle end103C of the first winding core103has a radius of curvature greater than about 11 mm. That is, in the scenario that the radius of curvature of the winding core is greater than a specific threshold (i.e., the minimum bending radius of the superconductor tape), it is possible to slightly bend the first superconductor tape301to attach along the surfaces of the winding cores.

As shown inFIGS.2A and2B, because the first winding core103includes a flat end and both ends of the second winding core104are flat, the first superconductor tape301cannot properly attach to the surface near the right angles thereof due to its physical property. Therefore, in some embodiments of the present disclosure, a plurality of guiding components are provided to eliminate the right angles within the winding path.

Referring toFIG.5, which illustrates the structure feature of the winding cores and a plurality of guiding components by using the pole units81,82in the upper magnetic core body100A; in some embodiments, the superconductor undulator structure further includes a first guiding component411connected to the second winding core104and the semicircle end103C of the first winding core103. To be more precise, the first guiding component411is in contact with the entire semicircle end103C of the first winding core103and one of the flat ends of the second winding core104. Moreover, the superconductor undulator structure also includes a second guiding component412connected to the flat ends of the first winding core103and the second winding core104, wherein both the flat ends thereof are entirely covered by the second guiding component412. In some embodiments, both the first guiding component411and the second guiding component412have semicircle profiles, wherein these guiding components have radii of curvature greater than the minimum bending radius of the superconductor tape. In some embodiments, the shape of the first guiding component411is different to the shape of the second guiding component412because the first guiding component411has a recess for corresponding to the semicircle end103C of the first winding core103. In some embodiments, the thicknesses of the first guiding component411and the second guiding component412are either identical to or smaller than the thicknesses of the first winding core103and the second winding core104. The guiding components411,412,421and422are made of copper, aluminum, alloys thereof, or the like. In some embodiments, the guiding components411,412,421and422are made of non-magnetic material.

The first guiding component411and the second guiding component412are configured to provide a continuous surface for winding the first superconductor tape301thereon. As shown inFIG.5, the flat end of the first winding core103and the two flat ends of the second winding core104are covered by the guiding components, and the profiles of the winding cores are altered to a single racetrack shape for winding the superconductor tapes thereon.

Referring toFIG.6, which illustrates the structure feature of the winding cores and a plurality of guiding components by using the pole units83,84in the lower magnetic core body100B; like the embodiment shown inFIG.5, the two flat ends of the third winding core107inFIG.6are covered by a first guiding component421and a second guiding component422, while the flat end and the semicircle end108C of the fourth winding core108are covered by the first guiding component421and the second guiding component422, respectively. Like previously discussed, these guiding components can eliminate the right angles within the winding path, and thus the profiles of the winding cores in the lower magnetic core body100B are also altered to a single racetrack shape for winding the superconductor tapes thereon.

Furthermore, the cooling components employed in the present disclosure are also illustrated inFIGS.5and6. As shown inFIG.5, a metal plate set51is sandwiched by the first half magnetic pole array (presented by the pole unit81) and the second half magnetic pole array (presented by the pole unit82) for cooling the superconductor tapes. In some embodiments, the metal plate set51includes a first metal plate that separated into a first portion511aand a second portion511b, and a second metal plate512stacked below the first metal plate. In some embodiments, the metal plate set51is made of copper. Similarly, as shown inFIG.6, a metal plate set52is sandwiched by the third half magnetic pole array (presented by the pole unit83) and the fourth half magnetic pole array (presented by the pole unit84) for cooling the superconductor tapes. In some embodiments, the metal plate set52includes a first metal plate that separated into a first portion521aand a second portion521b, and a second metal plate522stacked below the first metal plate. In fact, the metal plate set51is substantially identical to the metal plate set52. In some embodiments, an upper cooling bar70A and a lower cooling bar70B that connected to a cryo-cooler may be utilized to cool the upper magnetic core body100A and the lower magnetic core body100B by in contact therewith, while the upper cooling bar70A and the lower cooling bar70B are connected to an upper cooling channel71A and a lower cooling channel71B, respectively. In some embodiments, more cooling bars may be used to cool the coil structure30, which will be described later.

In the present disclosure, the metal plate sets51,52are cooled by using cryo-coolers, which is a cooling device that may reach cryogenic temperatures. Generally, the operating temperature of superconductor materials is performed by the combination of liquid helium and cryo-coolers, or by using liquid helium solely; however, since the superconductor tapes employed in the present disclosure are made of high-temperature superconductor material, it is expected that the less complex and inexpensive cooling structure (i.e., the cryo-coolers) can be employed thereby.

The structure feature of the metal plate sets51,52are related to the winding technique disclosed in the present disclosure. Referring toFIGS.7A and7B, whereinFIG.7Ashows the exploded view of the metal plate set51inFIG.7B, and several superconductor tapes are included for illustration. As shown inFIG.7A, the first portion511aof the first metal plate and the second metal plate512may include flat surfaces S1and S2, respectively. These flat surfaces S1and S2are configured to in contact with the joint portions of the superconductor tapes because the joint portions of the superconductor tapes may heat during the operating so that the cooling concept in the present disclosure is focused on the joint portions of the superconductor tapes.

As previously illustrated and mentioned inFIG.4C, each of the second superconductor tapes302is substantially employed as a termination joint to electrically connect to the first superconductor tapes301of adjacent magnet coils; therefore, in some embodiments, a first number of the second superconductor tapes302(or called inner second superconductor tapes) are entirely sandwiched by the flat surface S1of the first metal plate and the flat surface S2of the second metal plate512. Such flatly sandwiched feature is different from the conventional technique because the joint portions of the superconductor tapes in a conventional undulator were used to be disposed at the turnaround structures of the winding cores.

On the other hand, by disposing the second superconductor tapes302on the abovementioned flat surfaces, it will be much effective in cooling the coil structure, and it is ensured that the use of cryogen such as liquid helium is completely avoidable.

In some embodiments, the metal plate set is made of copper. Moreover, the first metal plate of the metal plate set51can be divided into two portions. As shown inFIG.7A, the second portion511bis in proximity to a side of the metal plate set51and has a thickness increased gradually. The second portion511bof the first metal plate is configured to guide the first superconductor tapes301to be wound on the semicircle end103C of the first winding core103, therefore, the first superconductor tapes301may smoothly pass the route between the metal plate set51and the first winding core103.

Since the lower magnetic core body100B is symmetric to the upper magnetic core body100A, the structure features of the metal plate set52between the third half magnetic pole array105and the fourth half magnetic pole array106of the lower magnetic core body100B is substantially identical to the metal plate set51and are omitted here for brevity.

Referring toFIG.8, in some embodiments, the superconductor undulator structure includes a third guiding component413in proximity to the first guiding component411. The third guiding component413is configured to alter a direction of the first superconductor tape301extending from the first guiding component411. The third guiding component413may provide a flat surface S31as the flat surfaces S1, S2in the metal plate set51previously disclosed inFIG.7A.

In some embodiments, the flat surface S31of the third guiding component413may be used to in contact with the outer superconductor tape portion34of the coil structure30winding on the upper magnetic core body100A. The second superconductor tapes302within the outer superconductor tape portion34of the coil structure30are free from sandwiched by the metal plates of the metal plate sets51,52. That is, in some embodiment, the first number of the second superconductor tapes302(inner second superconductor tapes) are directly cooled by the metal plate sets51,52, while a second number of the second superconductor tapes302(or called outer second superconductor tapes) are spaced apart from the first half upper magnetic pole array101and the second half upper magnetic pole array102by the third guiding component413. These second superconductor tapes302are in proximity to the flat surface S31of the third guiding component413can be cooled by a third cooling bar72, wherein the third cooling bar72is connected to the cryo-cooler as well. In some embodiments, the third guiding component413is made of copper and can be cooled by the cryo-coolers to maintain a suitable operating temperature to the first superconductor tape301and the second superconductor tape302thereon.

In some embodiments, the second superconductor tapes302free from covered by the metal plate set51are disposed at a side of the upper magnetic core body100A due to the third guiding component413. In some embodiments, the third guiding component413may have more than one curved portion to guide the direction of the first superconductor tapes301to perpendicular to the magnetic core body (100A or100B), and each of the curved portions has a radius of curvature greater than about 11 mm to match the physical property of the superconductor tapes.

FIGS.9A and9Bare used to illustrate the positions of the coil structure and the current direction (illustrated by arrows) in the superconductor undulator structure, wherein most of the reference signs of the structures are labeled inFIG.8and omitted inFIGS.9A and9Bfor brevity. In some embodiments of the present disclosure, the current is provided by a power supply continuously, which means the superconductor undulator structure does not operate under a built-in persistent current. Referring toFIG.9A, by using one portion of the upper magnetic core body100A as an example, the current may come from a first termination61(within the inner superconductor tape portion33previously shown inFIG.4C) which has a second superconductor tape302therein, and the current may pass through the first superconductor tape301that wound along the route sequentially comprises: (a) the interface between the first portion511aand the second portion511bof the first metal plate; (b) the interface between the recess of the first guiding component411and the semicircle end103C of the first winding core103; (c) an upper surface of the first winding core103; (d) a curved surface of the second guiding component412; (e) a lower surface of the second winding core104; and (f) a curved surface of the first guiding component411. After winding the sections (c) to (f) for one or more times, the first superconductor tape301is further guided to a second termination62(within the outer superconductor tape portion34previously shown inFIG.4C) by the guiding of the third guiding component413. A second superconductor tape302is located at the second termination62to bridge another first superconductor tape301and make a turnaround of the current.

FIG.9Billustrates another portion of the upper magnetic core body100A that just adjacent to the one shown inFIG.9A, and the superconductor tape inFIG.9Bis electrically connected to the superconductor tape inFIG.9Athrough the second superconductor tape302located at the second termination62, therefore, the current may come from the second termination62and pass through the first superconductor tape301that wound along the route sequentially comprises the aforementioned sections (f) to (a). A second superconductor tape302is located at the third termination63to bridge still another first superconductor tape301and make a turnaround of the current again, and so on.

Referring toFIG.10, in some embodiments, the superconductor undulator structure includes another third guiding component423in proximity to the first guiding component421. The third guiding component423may provide another flat surface S32for the entirely and flatly contact of the outer superconductor tape portion34of the coil structure30winding on the lower magnetic core body100B. In some embodiments, the third guiding component413employed to the upper magnetic core body100A is different from the third guiding component423employed to the lower magnetic core body100B, because both the third guiding components413and423guide the first superconductor tapes301toward the upper side of the superconductor undulator module, and therefore even though the upper and lower portions of the superconductor undulator structure are almost symmetric, the structure of the third guiding components413and423should be different. In some embodiments, another third cooling bar72may be disposed in proximity to the flat surface S32of the third guiding component423for cooling the outer superconductor tape portion34of the coil structure30.

FIGS.11A and11Bare used to illustrate the positions of the coil structure and the current direction in the superconductor undulator structure, wherein most of the reference signs of the structures are labeled inFIG.10and omitted inFIGS.11A and11Bfor brevity. Referring toFIG.11A, by using one portion of the lower magnetic core body100B as an example, the current may come from a fourth termination64which has a second superconductor tape302therein, and the current may pass through the first superconductor tape301that wound along the route similar with the route previously shown inFIG.9Aand is omitted here for brevity. The first superconductor tape301is further guided to a fifth termination65by the guiding of the third guiding component423. A second superconductor tape302is located at the fifth termination65to bridge another first superconductor tape301and make a turnaround of the current.

FIG.11Billustrates another portion of the lower magnetic core body100B that just adjacent to the one shown inFIG.11A, and the superconductor tape inFIG.11Bis electrically connected to the superconductor tape inFIG.11Athrough the second superconductor tape302located at the fifth termination65, therefore, the current may come from the fifth termination65and pass through the first superconductor tape301that wound along the route similar with the route previously shown inFIG.9B. The first superconductor tape301is further guided to a sixth termination66by the guiding of the third guiding component423. A second superconductor tape302is located at the sixth termination66to bridge still another first superconductor tape301and make a turnaround of the current again, and so on.

FIGS.12A to12C and13A to13Cillustrate several operations for manufacturing the superconductor undulator structure in previously shown embodiments. Referring toFIG.12A, a plurality of coil units300are formed prior to winding the superconductor tapes. In some embodiments, each of the coil units300includes two first superconductor tapes301attached to two edges of a second superconductor tape302, respectively. Next, referring toFIG.12B, the coil units300may be arranged over one of the metal plates of the metal plate set51(e.g., the second metal plate512). The numbers of the coil units300arranged over the metal plate is depending on the numbers of the winding cores of the magnetic core body, whereas the numbers inFIG.12Bfor illustration only. The plurality of coil units300is then be sandwiched by the metal plate set51, wherein each of the first superconductor tapes301outwardly extends from a side of the metal plate set extended from a side of the metal plate set51. Then, referring toFIG.12C, a magnetic core body (e.g., the upper magnetic core body100A) is received, wherein the magnetic core body includes a first half magnetic pole array101and a second half magnetic pole array102vertically aligned to the first half magnetic pole array101. The metal plate set51with the plurality of coil units300therein is disposed between the first half magnetic pole array101and the second half magnetic pole array102. Afterward, the first superconductor tapes301can be wound on the magnetic core body. The directions of the magnetic field are also labeled inFIG.12Cby using wide arrows.

After the pre-winding operations shown inFIGS.12A to12C, the details of the winding disclosed in the present disclosure are illustrated inFIGS.13A to13C. Referring toFIG.13A, the first superconductor tapes301(illustrated by arrows) may be wound along the semicircle end103C of each of the first winding cores103. Next, the first superconductor tapes301may be wound along an upper surface of each of the first winding cores103, a curved surface of each of the second guiding components412, and a lower surface of the each of the second winding cores104, wherein each of the second guiding components412connects to a flat end of the first winding core104. Then, referring toFIG.13B, the first guiding component411is installed at the semicircle end103C of each of the first winding cores103, the semicircle end103C is thus covered by the first guiding component411. On the other hand, a racetrack shape is formed by the combination of the first guiding component411, the first winding core103, the second guiding component412, and the second winding core104, and the first superconductor tapes may wound on such racetrack-shaped winding structure one or more times. In addition, referring toFIG.13C, the first superconductor tape301may further be wound along the third guiding component413in proximity to the first guiding component411to alter a direction of the first superconductor tape301extending from the first guiding component411. Accordingly, the coil units300as previously shown inFIGS.12A and12Bmay be connected by jointing with other second superconductor tapes302at the third guiding component413.

As illustrated inFIG.11AandFIG.13A, or the vertical comparison betweenFIG.5andFIG.6, the coil structures30are wounded from the metal plate sets51,52to the outer surfaces of the winding cores through the semicircle ends103C and108C, respectively, wherein the semicircle ends103C and108C are located at two opposite sides of the superconductor undulator module and distanced from the electron beam between the upper and lower magnetic core body100A,100B by the same distance. In other words, the magnetic field distribution provided by the superconductor undulator module is symmetric to the electron beam.

Briefly, according to the above-mentioned embodiments, the superconductor undulator disclosed in the present disclosure can free from using cryogen for cooling. Furthermore, since the cooling mechanism is altered in the present disclosure, the structure for winding is also improved to fulfill the physical property of high-temperature superconductor tape. Overall, compared to the conventional superconductor undulators, the superconductor undulator may have better performance and lower cost since no cryogen is used and the joint of the superconductor tapes is optimized to be located on the flat surfaces of the metal plates, and the effective in cooling should be improved significantly.

In one exemplary aspect, a superconductor undulator structure is provided. The superconductor undulator structure includes a magnetic core body and a coil structure. The magnetic core body includes a first half magnetic pole array and a second half magnetic pole array vertically aligned to the first half magnetic pole array; a plurality of first winding cores in the first half magnetic pole array; and a plurality of second winding cores in the second half magnetic pole array. The coil structure is wound on the first winding cores and the second winding cores of the magnetic core body. The coil structure includes a plurality of first superconductor tapes in contact with each of the first winding cores and each of the second winding cores; and a plurality of second superconductor tapes, each of the second superconductor tapes is in contact with two adjacent first superconductor tapes.

In another exemplary aspect, a superconductor undulator module is provided. The superconductor undulator module includes an upper magnetic core body, a coil structure, a metal plate set, and a lower magnetic core body. The upper magnetic core body has a first half upper magnetic pole array and a second half upper magnetic pole array vertically aligned to the first half upper magnetic pole array. The coil structure is wound on the upper magnetic core body. The metal plate set is sandwiched by the first half upper magnetic pole array and the second half upper magnetic pole array, and a portion of the coil structure is sandwiched by two metal plates of the upper metal plate set. The lower magnetic core body is in proximity to a bottom of the upper magnetic core body.

In yet another exemplary aspect, a method of manufacturing a superconductor undulator structure is provided. The method includes the following operations. A plurality of coil units are formed, and each of the coil units includes two first superconductor tapes attached to two edges of a second superconductor tape, respectively. The plurality of coil units are sandwiched by a metal plate set, wherein each of the first superconductor tapes outwardly extends from a side of the metal plate set. A magnetic core body is received. The magnetic core body comprises a first half magnetic pole array and a second half magnetic pole array vertically aligned to the first half magnetic pole array. The metal plate set is disposed between the first half magnetic pole array and the second half magnetic pole array. The first superconductor tapes are wound on the magnetic core body.