JPS60205271A - Thermoelectric cooling type radiation detector - Google Patents

Abstract

PURPOSE:To dispense with liquid nitrogen while making noise components hard to overlap a signal from a radiation detection element by employing a thermoelectric coolor utilizing the Peltier effect of a semiconductor to cool a radiation detector. CONSTITUTION:Thermoelectric coolors 15a are connected in multiple stages at the bottom of a radiation element 1 to reduce the detection element 1 to a low temperature level. Then, the undersurface of the detection element 1 is cooled with the coolor 15a. Heat deprived of by the detection element 1 is absorbed by a coolor 15b via an internal cylinder 17 and transmitted to a lower flange 18. Then, the heat is transmitted to a fin 19 and dissipated by aircooling. On the other hand, the external cylinder 20 is made vacuum inside to prevent the transfer of heat depending on convection. The internal cylinder 17 is arranged to prevent radiant heat to the detection element 1 from the external cylinder 20. In addition, the use of O rings 23 and 24 generates a pressure between the undersurface of the cylinder 17 and the top surface of the coolor 15b and the undersurface of the coolor 15b and the top surface of a lower flange thereby improving the cooling efficiency with a better thermal contact.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention relates to a BAVi electronically cooled radiation detector, particularly as a method for cooling the electronically cooled radiation detector.

The present invention relates to a radiation detector that can be cooled simply by supplying direct current by using an electronic cooling element instead of the conventional method using liquid nitrogen.

[Technical background of the invention and its problems] Conventionally, liquid IIji elements have been used to cool radiation detectors. FIG. 1 is a vertical IOT view showing an example of a conventional cooling method for a radiation detection element. 1 is a radiation detection element, 2 is a radiation measuring section, and 3 is a signal line. The liquid nitrogen 6 stored in the liquid nitrogen container 7 is used to cool the radiation detection element 1. That is, the cooling rod 4 is inserted into the liquid stream 6. Since the cooling rod 4 is usually made of a metal with good thermal conductivity such as copper, the radiation detection element 1 is cooled to almost the same level as liquid nitrogen. The vacuum container 5 prevents heat transfer due to convection near the cooling rod. 08 is a liquid nitrogen supply port.

In the conventional example described above, a large liquid nitrogen container is required to cool the radiation detection element, so a large space is required for installation. In addition, it was necessary to constantly supply liquid nutrient, which required a great deal of maintenance effort.

[Object of the Invention] This invention has been made to solve the above-mentioned drawbacks, and has a structure in which the supply of liquid nitrogen is unpleasant and it is difficult to mix noise components with the noise component from the radiation detection element. The present invention provides a small and lightweight electronically cooled radiation detector.

[Summary of the Invention] According to the present invention, a radiation detector is cooled by an electronic cooler that utilizes the Bertier effect of a semiconductor, so that there is no need to supply liquid lyron. Furthermore, since the weak No. 46 generated by the radiation detection element is amplified in an electrically shielded container, the noise component is 1+>1. do not have. (The difference between this invention and Utility Model Application No. 56-119534 is that it uses a 1% electronic cooler multi-layered structure to lower the minimum attainable m degrees, and that it has a built-in amplifier to improve the % of No. 46. .) [Embodiments of the Invention] The present invention will be described in detail below with reference to the drawings.

FIG. 2 is a diagram showing the principle of the Beltier effect. When the n-type semiconductor 9 and the p-type semiconductor 10 are connected with gold Jill, and a current is passed from the DC power supply 14 through the metal 12.13,
The metal II surface absorbs heat, and the gold JIt12 and 13 generate heat. Therefore, if a radiation detector is installed on the endothermic side, cooling can be achieved simply by supplying electricity. 1.5
Vi electronic cooler is shown.

FIG. 3 is a longitudinal sectional view showing one embodiment of the electronically cooled radiation detector according to the present invention. First, the configuration will be explained. Below the radiation detection element 1, electronic coolers 15a are arranged in a multi-stage connection. The reason for using multiple stages is to increase the heat drop and lower the temperature of the radiation detection element. A fixing jig 16 is placed around the radiation detection element. The fixing jig 16 and the electronic cooler 15M are housed within the inner cylinder 17. An electronic cooler 15b is arranged at the bottom of the inner cylinder 17, and a lower flange 18 and fins 1 are arranged at the bottom of the electronic cooler 15b.
Place 9. Further, the inner space of the lower flange 18 is
It is evacuated from the exhaust port 22 to create a vacuum. 23 and 24 are O-rings for maintaining airtightness. It is a 25Vi amplifier. 26
This is an airtight connector used for transmitting amplifier signals and direct current supplied to electronic coolers.

Next, the effect will be explained. The lower surface of the radiation detection element is cooled by a single electronic cooler 15M.

Since the electronic coolers 15a are thermally connected in series,
The heat removed by the radiation detection element 1 is transferred to the inner cylinder 17. The heat transferred to the inner cylinder 17 is transferred to the electronic cooler 15
b absorbs heat, and the heat is transferred to the lower flange 18. Furthermore, the heat of the lower flange is transferred to the fins 19, and the heat is dissipated from the fins by air cooling. As described above, the heat of the radiation detection element is transferred to the fins by the electronic cooler, so the fins may be cooled by forced air cooling or natural air cooling.

On the other hand, the inside of the outer cylinder 20 is lined to prevent heat transfer due to convection. The interior of the inner cylinder and the upper space of the fixing jig are also vacuumed. The inner cylinder 17 is for preventing radiant heat from the outer cylinder 20 to the radiation detection element 1, and the inner cylinder 17 is used to prevent the outer cylinder 2 from being radiated by the operation of the electronic cooler 15b.
The temperature is several tens of degrees C lower than that of U, and the amount of heat input to the radiation detection element 1 is reduced. The O-ring 23 is used for airtight sealing to create a vacuum inside the outer cylinder side, and the O-ring 23 is used for pressurization to improve the heat transfer performance of the electronic cooler 15b.By using this, Since pressure is applied between the lower surface of the inner cylinder 17 and the upper surface of the electronic cooler 15b, and between the lower surface of the electronic cooler 15b and the upper surface of the lower flange, thermal contact is improved and cooling efficiency is improved. It is also possible to fasten the space between the inner cylinder and the lower flange with screws, but in this case, the heat from the lower flange on the high temperature side flows into the inner cylinder through the screws, increasing the temperature of the inner cylinder and reducing cooling efficiency. The electronic circuit 25 is for amplifying the weak signal generated by the radiation detection element 1.
By housing it inside the outer cylinder 20, the weak 1g signal is amplified while being shielded from external electric fields, so a good signal with a high percentage can be extracted from the airtight connector. In addition to the above, the airtight connector 26 is used for transmitting current from the DC power supply 14 to the electronic cooler 15.
It is also used to supply power to the electronic circuit 5. 27 is a window for detecting radiation.

Figure m4 is a sectional view taken along the line A-A' in Figure 3, and shows only the electronic circuit 5 and the inner cylinder 17. As shown in the figure, by forming the electronic circuit board into a horseshoe shape, it becomes possible to install it between the inner cylinder 17 and the outer cylinder 20.

[Advantageous Effects] The following effects are expected by using the present invention described above.

1) Since the supply of liquid nitrogen is no longer necessary, long-term operation without maintenance is possible.

2) Since the supply of liquid nitrogen is no longer required, the shovel can be made smaller and
Since it is a light vehicle, there are fewer restrictions regarding the location of the installation.

3) Installation port can be installed even under radiation conditions that cannot be easily accessed by people.
become capable.

4) Since the a-weak signal is amplified in an electric field-shielded atmosphere, the "/N" of No. 48 is improved and radiation detection sensitivity is increased.

[Modifications] 1) In the present invention, the heat transferred to the lower flange is air-cooled using fins, but it is not limited to this method and cooling water may be used for cooling.02) In the present invention, the heat transferred to the lower flange is cooled by air. Although a fixing jig was used to fix the detection element, it may also be fixed to the electronic cooler with adhesive.

[Brief explanation of drawings]

Fig. 1 is a longitudinal cross-sectional view showing an example of a conventional cooling method, Fig. 2 is an explanatory diagram of the principle of the Peltier effect, and Fig. tJ43 is a longitudinal cross-sectional view showing an electronically cooled radiation detector which is an embodiment of the present invention. FIG. 4 is a cross-sectional view of the shape of the t-shaped circuit board and the inner cylinder. 1... Radiation detection element 2... Radiation measurement section 3...
・Signal m 4...Cooling rod 5...Vacuum container 6...Liquid 9I element 7...Liquid nitrogen container 8...Supply port 9...N-type semiconductor 10...
・pa! ! Semiconductor II, 12.13...Metal 1
4...DC power supply 15...Electronic cooler 16...Identification jig 17...Inner cylinder 18...Lower flange 1
9...Fin 20...Outer cylinder 21...Upper flange 22...Exhaust port 2: (, 24...0 ring 25...Electronic 1pj path; Shiro...Air kidney connector
27... Radiation #i! Detection Window Agent Patent Attorney Noriyuki Chika (1 person) Figure 1 Figure 2 Figure 3 Figure t! 5m t'/ Figure 4

Claims (2)

[Claims] (1) A radiation detection Yonago, a first multi-stage electronic cooler that cools it using the Bertier effect, an inner cylinder installed around the radiation detection element, and a second cooler that cools the inner cylinder. an electronic cooler, an outer container written on the outside of the inner cylinder, flanges installed above and below the outer cylinder, a pair of airtight means installed between the outer cylinder and the upper and lower flanges; PI+1: an airtight connector having an outer cylinder, an electronic circuit for the radiation detection element connected to a space between the inner cylinder and the outer cylinder, and a direct current and power source for the electronic cooler. Noodles and child cooling type radiation gland detector. (2) An electronically cooled radiation detector according to claim 1, characterized in that the outer cylinder and the flange have an airtight welded structure.