Particle detection and imaging devices

Abstract

To provide a particle detector which can suppress heat inflow and in which multiple superconductive nano strips can be arranged.SOLUTION: A particle detector according to an embodiment comprises: a detector which includes a plurality of superconductive nano strips and detects particles from a particle generation source; a conversion mechanism which has channels provided correspondingly to the plurality of superconductive nano strips and converts an analog signal from the corresponding superconductive nano strip into a digital signal; an aggregation mechanism which aggregates output from the conversion mechanism; a first temperature maintenance part which maintains a temperature to a first temperature equal to or less than the superconducting transition temperature; a first low-temperature container which stores the first temperature maintenance part; and a vacuum container which stores the conversion mechanism and the first low-temperature container and has an opening through which the particles from the particle generation source pass. The detector is stored in the first low-temperature container and connected to the first temperature maintenance part. The conversion mechanism is maintained to be equal to or greater than the first temperature. The aggregation mechanism is arranged on an outside of the first low-temperature container.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to particle detection devices and imaging devices. [Background technology]

[0002] A particle detection device using a superconducting single photon detector (SSPD) is known. This particle detection device generates a pulse signal when an X-ray photon collides with one of the multiple superconducting nanostrips that make up the SSPD, and detects the number of photons (particles) by counting the number of pulses in this generated pulse signal.

[0003] However, SSPDs are maintained in a cryogenic container below the superconducting transition temperature. Therefore, if the mechanism for counting pulse signals (counter) is installed on the room temperature side, a large amount of heat will flow into the container from room temperature. In particular, when using SSPDs in image generation devices, the number of superconducting nanostrips must be more than 100. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-16543 [Patent Document 2] Patent No. 541922 Summary of the Invention [Problem to be solved by the invention]

[0005] The present embodiment provides a particle detection device capable of suppressing heat inflow and an image generation device using the particle detection device. [Means for solving the problem]

[0006] The particle detection device of this embodiment comprises a detector including a plurality of superconducting nanostrips for detecting particles from a particle generation source, a conversion mechanism having channels corresponding to the plurality of superconducting nanostrips and converting analog signals from the corresponding superconducting nanostrips into digital signals, a collection mechanism for collecting the output from the conversion mechanism, a first temperature maintenance unit for maintaining a first temperature below the superconducting transition temperature, a first cryogenic container for storing the first temperature maintenance unit, and a vacuum container for storing the conversion mechanism and the first cryogenic container and having an opening through which the particles from the particle generation source pass, wherein the detector is stored in the first cryogenic container and connected to the first temperature maintenance unit, the conversion mechanism is maintained at a temperature above the first temperature, and the collection mechanism is positioned outside the first cryogenic container. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view showing a particle detecting device according to a first embodiment. [Figure 2] FIG. 1 is a circuit diagram showing a particle detection device according to a first embodiment. [Figure 3] FIG. 2 is a perspective view illustrating the operating principle of the particle detection device. [Figure 4] FIG. 3 is a waveform diagram illustrating the operating principle of the particle detection device. [Figure 5] FIG. 4 is a waveform diagram showing the output of the particle detector. [Figure 6] FIG. 4 is a cross-sectional view showing a particle detecting device according to a first modified example of the first embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing a particle detecting device according to a second modified example of the first embodiment. [Figure 8] FIG. 10 is a cross-sectional view showing a particle detecting device according to a third modified example of the first embodiment. [Figure 9] FIG. 10 is a cross-sectional view showing a particle detecting device according to a fourth modified example of the first embodiment. [Figure 10] FIG. 10 is a cross-sectional view showing a particle detecting device according to a fifth modified example of the first embodiment. [Figure 11] FIG. 10 is a circuit diagram showing a particle detecting device according to a sixth modified example of the first embodiment. [Figure 12] FIG. 6 is a cross-sectional view showing a particle detecting device according to a second embodiment. [Figure 13] FIG. 10 is a circuit diagram showing a particle detection device according to a third embodiment. [Figure 14] FIG. 10 is a circuit diagram showing a particle detection device according to a fourth embodiment. [Figure 15] FIG. 10 is a cross-sectional view showing a particle detecting device according to a fifth embodiment. [Figure 16] FIG. 13 is a cross-sectional view showing a particle detecting device according to a modification of the fifth embodiment. [Figure 17] FIG. 13 is a cross-sectional view showing a particle detecting device according to another modified example of the fifth embodiment. [Figure 18] FIG. 10 is a block diagram showing an image generating apparatus according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc. are not necessarily the same as those in reality. Even when the same part is shown, the dimensions and ratios may be different depending on the drawing.

[0009] (First embodiment) The configuration of a particle detection device according to a first embodiment is shown in Fig. 1. The particle detection device 100 of the first embodiment includes a superconducting single photon detector (SSPD) 110, a constant current power supply 120, a conversion mechanism 130, a collection mechanism 140, a cooling mechanism 150, and a computer 160.

[0010] The cooling mechanism 150 includes a first cryogenic container 152, a second cryogenic container 154 that houses the first cryogenic container 152 inside, a vacuum container 156 that houses the second resistance container 154 inside, and a refrigerator 170.

[0011] The refrigerator 170 includes a first temperature maintaining unit 172 and a second temperature maintaining unit 174, and performs freezing in two stages. The first temperature maintaining unit 172 is housed in the first cryogenic container 152. The second temperature maintaining unit 174 is housed in the second cryogenic container 154. The SSPD 110 is connected to the first temperature maintaining unit 172, and is maintained at a temperature T1 that is equal to or lower than the superconducting transition temperature of the superconducting material that constitutes the SSPD 110.

[0012] The conversion mechanism 130 is connected to a second temperature maintaining unit 174 and maintained at a temperature T2 equal to or higher than the temperature T1. For example, when the superconducting material is niobium, the temperature T1 is in the range of 20% of the superconducting transition temperature to the superconducting transition temperature (1.84 to 9.2 K), and may be, for example, about 4 K. The temperature T2 is 100 K or lower, and may be, for example, about 65 K. The first cryogenic vessel 152 and the second cryogenic vessel 154 are provided with windows 152a and 154a, respectively, that allow particles to pass through but block heat. When the particles to be detected are hard X-ray photons, aluminum foil or the like is used for the windows. Similarly, the vacuum vessel 156 is provided with an opening 156a. The vacuum vessel 156 is also connected to a vacuum vessel 190 that houses a particle generation source 180. The vacuum degree of the vacuum vessel 156 is 1.0×10 -6 mbar or less is preferable.

[0013] 2, the SSPD 110 has N (N≧2) linear superconducting nanostrips 202 formed parallel to each other and at equal intervals on a substrate 201 such as a silicon wafer, where N is a natural number. The superconducting material that makes up the superconducting nanostrips 202 is, for example, niobium.

[0014] 2, the conversion mechanism 130 includes bias tees 204, amplifiers 205, and comparators 206 provided corresponding to the N superconducting nanostrips 202, respectively. The bias tees 204, amplifiers 205, and comparators 206 are arranged, for example, on a printed circuit board 203. The conversion mechanism 130 also includes a counter 207 that is arranged on the printed circuit board 203, has N channels provided corresponding to the N superconducting nanostrips 202, and is connected to the N comparators 206.

[0015] Each of the superconducting nanostrips 202 has one end grounded and the other end connected to the RF / DC terminal of a corresponding bias-tee 204. The DC terminal of the bias-tee 204 is connected to the constant current power supply 120. The RF terminal of the bias-tee 204 is connected to the input terminal of a corresponding amplifier 205. The output terminal of the amplifier 205 is connected to the input terminal of a corresponding comparator 206. The output terminal of the comparator 206 is connected to the input terminal of a counter 207.

[0016] The concentrator / distributor circuit 209 is provided on, for example, a printed circuit board 208. The concentrator / distributor circuit 209 receives an output signal from the counter 207 at an input terminal. The output terminal of the concentrator / distributor circuit 209 is connected to the computer 160. The counter 207 and the concentrator / distributor circuit 209 are semiconductor circuits, and are fabricated using, for example, an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). The concentrator / distributor circuit 209 is stored in a region outside the second cryogenic chamber 154 and inside the vacuum chamber 156. At this time, the concentrator / distributor circuit 209 is cooled by, for example, a Peltier element 210.

[0017] (Particle detection device operating principle) Next, the operating principle of the particle detection device 100 will be described with reference to FIGS. 3 and 4. As shown in FIG. 3, a particle 301, such as an X-ray photon, generated by a particle generation source 180 collides with a single superconducting nanostrip 202. A current not exceeding the critical current of superconductivity flows through the superconducting nanostrip 202 from the constant-current power supply 120 via a bias-tee 204, as indicated by arrow 302. The bias-tee 204 functions as a device for applying direct current without affecting the high-frequency signal. A region 303 that transitions from superconductivity to normal conductivity is formed near the point where the particle 301 collides with the superconducting nanostrip 202. Because region 303 is in a normal conductive state, it has resistance, and current 304 flows to bypass region 303. Then, region 305, where the current becomes dense due to this bypass, exceeds the critical current of superconductivity. As a result, region 305 transitions to normal conductivity, breaking the superconducting nanostrip 202, generating electrical resistance and temporarily increasing the voltage. After that, region 305 returns to the superconducting state due to cooling. This voltage change generates a pulse signal. The pulse signal is amplified by amplifier 205, and when the height of the amplified pulse signal 401 is equal to or greater than threshold value 402, comparator 206 outputs a square wave 404 with a pulse width 403 of, for example, about 100 nanoseconds.

[0018] The counter 207 has a section for recording the count value of each channel. When one square wave 404 reaches the counter 207, the count value of the corresponding channel is incremented by 1. In this way, the counter 207 records the count value of each of the N superconducting nanostrips.

[0019] When the concentrator / distributor circuit 209 receives a start command from the computer 160, it resets the count values of all channels recorded in the counter 207 to zero. After a predetermined time has elapsed, it reads the count values from the counter 207, transfers the count values of all channels to the computer 160, and resets the count values of all channels to zero again, repeating this operation.

[0020] The operation is terminated when a termination command is received from the computer 160. By plotting the count value against the position of the superconducting nanostrip corresponding to each channel, a one-dimensional position distribution of the number of particles that have reached the SSPD 110 is obtained, as shown in Figure 5 .

[0021] It is also possible to obtain a two-dimensional position distribution of the number of particles that have reached the SSPD 110 by obtaining a one-dimensional position distribution while moving the SSPD 110 relative to the particle source 180. This two-dimensional position distribution corresponds to an X-ray image if the particles are X-ray photons.

[0022] The pulse signal generated by the SSPD 110 is an analog signal with a half-width 405 shown in Figure 4 of, for example, about 2 nanoseconds (equivalent to a frequency of 500 MHz). For this reason, a high-speed transmission flexible board is used as the cable 211 connecting the SSPD 110 and the conversion mechanism 130, which has little high-frequency signal loss and allows for multiple wires to be arranged in a space-saving manner. The high-speed transmission flexible board is structured so that the ground wire surrounds the signal wire, similar to a coaxial cable. If the total cross-sectional area of the conductive part (signal wire and ground wire) is S, the length of the high-speed transmission flexible board is L, and the thermal conductivity of the material composing the conductive part is k, the amount of heat W propagating through the signal wire and ground wire is expressed by the following equation (1):

number

[0023] On the other hand, the signal used for communication between the aggregation mechanism 140 and the conversion mechanism 130 is a digital signal with a pulse width of about 5 microseconds (200 kHz). Generally, the higher the signal frequency, the smaller the cross-sectional area of the conductive part per signal line, and the longer the distance, the greater the signal energy loss. Furthermore, compared to analog signals, even if there is a certain amount of loss, the impact is less because the value is only "0" or "1." Therefore, for the cable 212 connecting the conversion mechanism 130 and the aggregation mechanism 140, a flexible board, flat cable, or twisted pair cable with a smaller cross-sectional area of the conductive part than a high-speed transmission flexible board is used, minimizing heat inflow.

[0024] Next, the effects of the first embodiment will be described. The cooling capacity of the second temperature maintaining unit 174 of the refrigerator 170 is approximately several tens of watts, which is extremely large compared to the cooling capacity of the first temperature maintaining unit 172, which is 1 W or less. In this embodiment, by connecting the conversion mechanism 130 to the second temperature maintaining unit 174, it is possible to sufficiently cool the conversion mechanism 130 even if it generates a large amount of heat. Furthermore, the length of the cable 211 connecting the SSPD 110 and the conversion mechanism 130 is shorter than when the conversion mechanism 130 is placed outside the vacuum vessel 156, and loss is sufficiently reduced even if the cross-sectional area of each signal line is small.

[0025] As described above, the total cross-sectional area of the conductive parts is determined by the cooling capacity of the first temperature maintenance unit 172, so if the cross-sectional area per signal line is reduced, it becomes possible to increase the number of signal lines, and as a result, it becomes possible to install an SSPD 110 with a large number of superconducting nanostrips 202.

[0026] Furthermore, by disposing the collecting mechanism 140 outside the second cryogenic container 154, it is possible to reduce the burden on the cooling capacity of the second temperature maintaining unit 174. By storing the collecting mechanism 140 inside the vacuum container 156, it becomes possible to cool it using the Peltier element 210 without condensation.

[0027] As described above, according to the first embodiment, it is possible to count the number of pulses of the SSPD 110 having a large number of superconducting nanostrips 202 by using the conversion mechanism 130 and the collection mechanism 140 made of semiconductor circuits that generate a large amount of heat, and it is possible to simultaneously obtain the one-dimensional position distribution of the number of particles over a wider range. In other words, it is possible to provide a particle detection device that can suppress heat inflow and that allows for a multi-line arrangement of superconducting nanostrips.

[0028] One possible method is to use a superconducting single flux quantum circuit as the counter and install it in an extremely low temperature environment, similar to the SSPD, to suppress heat inflow. However, unlike this embodiment, there is a problem in that there is no track record of creating large-scale superconducting single flux quantum circuit elements.

[0029] Next, a particle detecting device according to a modification of the first embodiment will be described. (First Modification) A particle detection device according to a first modified example is shown in Fig. 6. The particle detection device 100A of this first modified example has a configuration in which the conversion mechanism 130 is connected to a first temperature maintaining unit 172 and the collecting mechanism 140 is connected to a second temperature maintaining unit 174 in the particle detection device 100 of the first embodiment shown in Fig. 1.

[0030] (Second Modification) A particle detection device according to a second modification is shown in Fig. 7. The particle detection device 100B of this second modification has a configuration in which the collecting mechanism 140 in the particle detection device 100A of the first modification shown in Fig. 6 is arranged outside the second cryogenic container 154 and inside the vacuum container 156.

[0031] (Third Modification) A particle detection device according to a third modified example is shown in Fig. 8. The particle detection device 100C of this third modified example has a configuration in which the collecting mechanism 140 is arranged outside the vacuum vessel 156 in the particle detection device 100B of the second modified example shown in Fig. 7.

[0032] (Fourth Modification) A particle detection device according to a fourth modified example is shown in Fig. 9. The particle detection device 100D of this fourth modified example has a configuration in which the conversion mechanism 130 is connected to a second temperature maintaining unit 174 in the particle detection device 100A of the first modified example shown in Fig. 6.

[0033] (Fifth Modification) A particle detection device according to a fifth modified example is shown in Fig. 10. The particle detection device 100E of this fifth modified example has a configuration in which the collecting mechanism 140 is arranged outside the vacuum vessel 156 in the particle detection device 100D of the fourth modified example shown in Fig. 9.

[0034] The first to fifth modifications have the advantage that an optimum arrangement can be realized depending on the operating temperature range and heat generation amount of the conversion mechanism 130 and the collecting mechanism 140, and the cooling capacity of the first temperature maintaining unit 172 and the second temperature maintaining unit 174.

[0035] 8 or 10, when the concentrating mechanism 140 is arranged outside the vacuum vessel 156, a cooling fan and cooling water are used instead of the Peltier element 210 to cool the concentrator / distributor circuit 209. In this case, although the cooling temperature becomes higher, there are advantages in that the state of the concentrator / distributor circuit 209 can be visually confirmed and settings can be easily changed.

[0036] When the conversion mechanism 130 is connected to the first temperature maintaining unit 172 and the aggregation mechanism 140 is installed outside the second cryogenic container 154 and inside the vacuum container 156, as in the second modified example shown in Figure 7, or when the aggregation mechanism 140 is installed outside the vacuum container 156, as in the third modified example, the second temperature maintaining unit 174 and the second cryogenic container 154 are not necessarily required.

[0037] (Sixth Modification) When both the conversion mechanism 130 and the aggregation mechanism 140 are connected to the second temperature maintaining unit 174 as in the fourth modified example shown in Fig. 9, it is also possible to fabricate the conversion mechanism 130 and the aggregation mechanism 140 on a single substrate and fabricate the counter and the distribution circuit using a single FPGA or ASIC 601 as in the sixth modified example shown in Fig. 11. This has the effect of saving space.

[0038] (Second embodiment) A particle detection device according to a second embodiment will be described with reference to FIG. 12. A particle detection device 100F of this second embodiment uses a first refrigerator 702 and a second refrigerator 705 instead of the two-stage refrigerator 110 shown in FIG. 1. The first refrigerator 702 has a first temperature maintaining unit 701 that maintains a temperature at T1, and the first temperature maintaining unit 701 is housed in a first cryocontainer 703. The second refrigerator 705 has a second temperature maintaining unit 704 that maintains a temperature at T2. The second temperature maintaining unit 704 is housed in a second cryocontainer 706, and the first cryocontainer 703 and the second cryocontainer 706 are arranged side by side within a vacuum container. In this case, the cooling capacity of the second temperature maintaining unit 704 can be increased, and restrictions on the heat generation amount of the conversion mechanism 130 can be relaxed.

[0039] (Third embodiment) Next, a particle detecting device according to a third embodiment will be described with reference to Fig. 13. In the particle detecting device 100 of the first embodiment shown in Fig. 1 and Fig. 2, the conversion mechanism 130 has N bias tees 204, amplifiers 205, comparators 206, and one counter 207 arranged on one substrate 203.

[0040] In contrast to this, in the particle detection device of the third embodiment, the conversion mechanism 130 is divided into m boards. As shown in Fig. 13, the bias tees 204, amplifiers 205, and comparators 206 are arranged in n1, n2, ..., n on each of the m printed circuit boards 801. m n1, n2, . . ., n m Each counter 802 has N channels, where N=n1+n2+...+n m Each superconducting nanostrip 202 is connected to one bias tee 204, amplifier 205, and comparator 206, and is then connected to one channel of the counter 802. Each of the m counters 802 is connected to a concentrator / distributor circuit 803 on the concentrator 140. The functions and other configurations of each are the same as those explained in the first embodiment.

[0041] The particle detection device of the third embodiment can be applied even when the number N of superconducting nanostrips 202 exceeds the number of channels of the counter 802, and can obtain the same effect as in the first embodiment. This has the effect of further expanding the range of one-dimensional position distribution of the number of particles that can be obtained at one time.

[0042] (Fourth embodiment) Next, a particle detecting device according to a fourth embodiment will be described with reference to Fig. 14. In the first embodiment shown in Figs. 1 and 2, the converting mechanism 130 is made up of a bias tee 204, an amplifier 205, a comparator 206, and a counter 207.

[0043] In the fourth embodiment, as shown in Fig. 14, a conversion mechanism 901 includes N bias tees 204, amplifiers 205, and comparators 206. An aggregation mechanism 902 includes a counter 903 and a concentrator / distributor circuit 904. In this case, the counter 903 may be divided into m counters, or the counter 903 and the concentrator / distributor circuit 904 may be fabricated in a single FPGA or ASIC, as in a seventh modification shown in Fig. 12.

[0044] The signal generated from comparator 206 is a square wave with a pulse width of about 100 nanoseconds, and is binary data, i.e., a digital signal, indicating whether or not a pulse signal has been generated from SSPD 110. Since information is not lost even if there is some loss, a cable with a small cross-sectional area can be used for cable 905 connecting conversion mechanism 901 and collection mechanism 904. Furthermore, if amplifier 205 can amplify the pulse signal to an extent that sufficiently compensates for the loss in the cable connecting conversion mechanism 901 and collection mechanism 904, comparator 206 may be omitted or may be located in the collection mechanism rather than the conversion mechanism. The other configurations are the same as those in the first embodiment.

[0045] The fourth embodiment makes it possible to obtain the same effect as the first embodiment in a different form. In this case, there is an advantage that the comparator, counter, and concentrator / distributor circuit can be used with an operating temperature range close to room temperature.

[0046] (Fifth embodiment) Next, a particle detecting device according to a fifth embodiment will be described with reference to Fig. 15. In the first embodiment shown in Fig. 1, the converting mechanism 130 is connected to the second temperature maintaining unit 174.

[0047] In the particle detection device 100G of the fifth embodiment, a connector 1000 is provided at the midpoint between the SSPD 110 and the conversion mechanism 130, and the connector 1000 is connected to the second temperature maintaining unit 174 to maintain the temperature of the connector at T2. In this case, the connector 1000 may be omitted, but in order to maintain the temperature of the cable (conductive part) at T2 at the part connected to the second temperature maintaining unit 174, the surface connecting the cable and the second temperature maintaining unit 174 is made sufficiently large. The conversion mechanism 130 is disposed outside the second cryogenic container 154 and in the vacuum container 156, and is cooled by a Peltier element 1001 (see FIG. 15 ).

[0048] 16 or 17, the conversion mechanism 130 and the aggregation mechanism 140 may be arranged outside the vacuum vessel 156, in which case they are cooled by a cooling fan or cooling water. s The amount of heat propagating through the cable 1002 connecting the connector 1000 and the conversion mechanism 130 is W c Let's say. W c W s The length, cross-sectional area and material of the conductive part of cable 1002 and the attachment position of connector 1000 are determined so that the cooling capacity of second temperature maintaining unit 174 is larger than the cooling capacity of second temperature maintaining unit 174, and smaller than the cooling capacity of second temperature maintaining unit 174. Because the cooling capacity of the second temperature maintaining unit is sufficiently large, it becomes possible to make the cross-sectional area of the conductive part of cable 1002 sufficiently large, and it becomes possible to sufficiently suppress loss of signals transmitted through cable 1002.

[0049] The fifth embodiment and its modifications enable the conversion mechanism to be disposed outside the cryogenic container, which has the effect of easing restrictions on the operating temperature of the conversion mechanism.

[0050] (Sixth embodiment) An image generating apparatus according to a sixth embodiment will be described with reference to FIG. 18 . The image generating apparatus of the sixth embodiment includes a particle generating source 180 that generates, for example, X-rays, any of the particle detecting devices of the first to fifth embodiments and their modified examples (e.g., the particle detecting device 100 of the first embodiment), and a controller 1100 that moves the sample 10 and the SSPD 110 of the particle detecting device 100 relative to each other. The sample 10 is placed between the particle generating source 180 and the SSPD 110, X-rays are irradiated onto the sample 10 from the particle generating source 180, and the X-rays that have passed through the sample 10 are detected by the SSPD 110. At this time, an X-ray image of the sample 10 can be obtained by moving the sample 10 and the SSPD 110 relatively using the controller 1100. For example, if the length and width of a superconducting nanostrip are approximately the same and the relative movement is along the direction in which the superconducting nanostrip extends, a two-dimensional image of the sample 10 can be obtained. When the relative movement is a rotational movement about a center line connecting the center of the SSPD 110 and the center of the particle source 180, a two-dimensional image of the sample 10 can be obtained. This image is generated by the computer 160. Note that the image generation may also be performed by a computer (not shown) that is disposed outside the particle detection device 100.

[0051] This sixth embodiment of the image generating device uses any of the particle detecting devices of the first to fifth embodiments or their modified examples, and therefore it is possible to obtain an image generating device that can suppress heat inflow and that can arrange superconducting nanostrips in multiple lines.

[0052] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0053] 110: superconducting single photon detector, 120: constant current power supply, 130: conversion mechanism, 140: collection mechanism, 150: cooling mechanism, 152: first cryocontainer, 154: second cryocontainer, 156: vacuum vessel, 160: computer, 170: refrigerator, 172: first temperature maintaining unit, 174: second temperature maintaining unit, 152a: window, 154a: window, 156a: opening, 201: substrate, 202: superconducting nanostrip, 203: substrate, 204: bias tee, 205: amplifier, 206: comparator, 207: counter, 208: substrate, 209: collector / distributor, 210: Peltier element, 211: cable, 212: cable, 301: particle, 302 : Arrow, 303: Normal transition region, 304: Current, 305: Normal transition region, 401: Pulse signal, 402: Threshold value, 403: Pulse width, 404: Square wave, 405: Pulse width, 601: Counter / concentrator / distributor, 701: First temperature maintaining unit, 702: First refrigerator, 703: First cryocontainer, 704: Second temperature maintaining unit, 705: Second refrigerator, 706: Second cryocontainer, 801: Substrate, 802: Counter, 803: Concentrator / distributor, 901: Conversion mechanism, 902: Aggregation mechanism, 903: Counter, 904: Concentrator / distributor, 905: Cable, 1000: Connector, 1001: Peltier element, 1002: Cable, 1100: Controller

Claims

1. a detector for detecting particles from the particle source, the detector including a plurality of superconducting nanostrips; a conversion mechanism having channels provided corresponding to the plurality of superconducting nanostrips, for converting analog signals from the corresponding superconducting nanostrips into digital signals; an aggregation mechanism that aggregates outputs from the conversion mechanisms; a cable connecting the detector and the conversion mechanism; a first temperature maintaining unit that maintains the temperature at a first temperature that is equal to or lower than the superconducting transition temperature; a first cryogenic container that houses the first temperature maintaining unit; a second temperature maintaining unit that maintains the temperature at a second temperature equal to or higher than the first temperature; a second cryocontainer that houses the second temperature maintenance unit and the first cryocontainer; a vacuum vessel containing the second cryogenic vessel and having an opening through which the particles from the particle source pass; Equipped with the detector is housed in the first cryocontainer and connected to the first temperature maintenance unit; the cable includes a portion that is connected to the second temperature maintaining unit and is maintained at the second temperature; the conversion mechanism is maintained at or above the second temperature; The particle detection device wherein the collection mechanism is located outside the second cryocontainer.

2. a connector at an intermediate point of the cable connecting the detector and the conversion mechanism, the connector being connected to the second temperature maintaining unit to maintain the second temperature; The cable includes a first cable connecting the detector and the connector, and a second cable connecting the connector and the conversion mechanism. The particle detection device of claim 1 .

3. The first and second cables are flexible substrates, and the cross-sectional area of the conductive portion of the first cable and the cross-sectional area of the conductive portion of the second cable are different from each other.

3. The particle detection device according to claim 2.

4. 2. The particle detection device according to claim 1, further comprising a connector at an intermediate point of the cable connecting the detector and the conversion mechanism, the connector being connected to a second temperature maintaining unit and maintained at the second temperature, and a quantity of heat propagating through the cable connecting the detector and the connector being smaller than a quantity of heat propagating through the cable connecting the connector and the conversion mechanism.

5. The particle detection device according to claim 1 , wherein the collecting mechanism operates at a temperature close to room temperature.

6. The particle detection device according to claim 1 , wherein the conversion mechanism is disposed outside the second cryogenic container, and the collecting mechanism is housed inside the vacuum container.

7. 6. The particle detection device according to claim 1, wherein the conversion mechanism is disposed outside the second cryogenic container, and the collecting mechanism is disposed outside the vacuum container.

8. The particle detection device of claim 7 , wherein the conversion mechanism is disposed outside the vacuum vessel.

9. The particle detection device according to claim 1 , wherein the conversion mechanism is housed in the second cryogenic container and connected to the second temperature maintaining unit, and the collecting mechanism is disposed outside the vacuum container.

10. 2. The particle detection device according to claim 1, wherein the conversion mechanism is housed in the second cryogenic container and connected to the second temperature maintaining unit, and the collecting mechanism is housed in the vacuum container.

11. a detector for detecting particles from the particle source, the detector including a plurality of superconducting nanostrips; a conversion mechanism having channels provided corresponding to the plurality of superconducting nanostrips, for converting analog signals from the corresponding superconducting nanostrips into digital signals; an aggregation mechanism that aggregates outputs from the conversion mechanisms; a cable connecting the detector and the conversion mechanism; a first temperature maintaining unit that maintains the temperature at a first temperature that is equal to or lower than the superconducting transition temperature; a first cryogenic container that houses the first temperature maintaining unit; a second temperature maintaining unit that maintains the temperature at a second temperature equal to or higher than the first temperature; a vacuum vessel containing the first cryogenic vessel and the second temperature maintaining unit, the vacuum vessel having an opening through which the particles from the particle generation source pass; Equipped with the detector is housed in the first cryocontainer and connected to the first temperature maintenance unit; the cable includes a portion that is connected to the second temperature maintaining unit and is maintained at the second temperature; the conversion mechanism is maintained at or above the second temperature; The particle detection device, wherein the collecting mechanism is disposed outside the first cryogenic container and operates at a temperature close to room temperature.

12. 12. The particle detection device according to claim 1, wherein the cable connected to the detector has a cross-sectional area of the conductive portion of the cable, a temperature difference between both ends of the cable, and a thermal conductivity of the conductive portion, the product of which is divided by the length of the cable, such that the product is 1 / 10 or less of the cooling capacity of the first temperature maintaining unit.

13. 13. The particle detecting device according to claim 1, wherein the digital signal output from the conversion mechanism has a pulse width of 50 nsec or more.

14. The plurality of superconducting nanostrips are divided into a plurality of groups, and the conversion mechanism is divided corresponding to the groups and arranged in parallel; 14. The particle detection device according to claim 1, wherein analog signals generated from the superconducting nanostrips belonging to each group are input to a conversion mechanism corresponding to each group.

15. 15. The particle detection device according to claim 1, wherein a cable connecting the detector and the conversion mechanism is a flexible substrate.

16. The particle detection device described in any one of claims 1 to 15, wherein the conversion mechanism is provided corresponding to the plurality of superconducting nanostrips, and comprises a bias tee that outputs a signal from the corresponding superconducting nanostrip and applies direct current to the corresponding superconducting nanostrip, an amplifier that amplifies the output of the bias tee, a comparator that compares whether the output of the amplifier is above a threshold value and outputs a digital signal when the output is above the threshold value, and a counter that counts the output from the comparator.

17. A detector for detecting particles from a particle source, the detector comprising a plurality of superconducting nanostrips; a conversion mechanism having channels provided corresponding to the plurality of superconducting nanostrips, for converting analog signals from the corresponding superconducting nanostrips into digital signals; an aggregation mechanism that aggregates outputs from the conversion mechanisms; a cable connecting the detector and the conversion mechanism; a first temperature maintaining unit that maintains the temperature at a first temperature that is equal to or lower than the superconducting transition temperature; a first cryogenic container that houses the first temperature maintaining unit; a second temperature maintaining unit that maintains the temperature at a second temperature equal to or higher than the first temperature; a second cryocontainer that houses the second temperature maintenance unit and the first cryocontainer; a vacuum vessel containing the second cryogenic vessel and having an opening through which the particles from the particle source pass; Equipped with the detector is housed in the first cryocontainer and connected to the first temperature maintenance unit; the cable includes a portion maintained at the second temperature; the conversion mechanism is maintained at or above the second temperature; the collecting mechanism is disposed outside the second cryocontainer; The particle detection device, wherein the conversion mechanism is disposed outside the second cryogenic container, and the collection mechanism is housed within the vacuum container.

18. 18. An image generating device comprising: the particle detection device according to any one of claims 1 to 17; the particle generation source; a controller that moves the detector of the particle detection device and a sample relatively; and an image generating unit that generates an image of the sample based on an output of the collecting mechanism.

Images