JP3018055B2 - Peltier cooled semiconductor detector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a Peltier cooled semiconductor detector for detecting radiation.

[0002]

2. Description of the Related Art The main components of a conventional Peltier cooled semiconductor detector are shown in FIGS. In FIG. 2, a semiconductor detector 1 for detecting radiation is connected via a cooling shaft 6 to a Peltier element 2 for cooling the semiconductor detector 1. The Peltier device 2 is connected to a heat sink 3 for heat dissipation of the Peltier device 2. The above-described apparatus is provided inside the cryostat 5 and provided with an ion pump 4 for keeping the inside of the cryostat 5 at a high vacuum. The cooling shaft 6 is for cooling the semiconductor detector 1 located away from the Peltier element 2, and is usually made of copper having good heat conductivity.

In FIG. 3, a heat shield 7 has a pipe-like structure surrounding the cooling shaft 6 and the semiconductor detector 1, and is usually connected to a lower stage than the uppermost stage of the Peltier device 2 and cooled. It is used as a shield for radiant heat.

[0004]

In the conventional Peltier-cooled semiconductor detector, the cooling efficiency of the detector 1 is poor due to the inflow of radiant heat from the cryostat 5 and the like, and there is a detector provided with a heat shield 7 for the purpose of improving the cooling efficiency. However, in addition to cooling the semiconductor detector with one Peltier element 2, it is necessary to cool down to the heat shield 7, and the cooling efficiency is lost accordingly.

Therefore, the cooling temperature of the semiconductor detector 1 becomes higher than the temperature of the uppermost stage of the Peltier element 2, and there is a problem that the performance of the detector 1 is limited. Furthermore, although the vacuum is kept high by the ion pump 4,
The cooling part by the Peltier element 2 serves as a trap for the residual gas. If the residual gas is trapped on the surface of the detector 1 or the FET, the detector may be disturbed by incident X-rays or an increase in the surface leakage current of the detector or the FET. There is a problem that the performance as No. 1 is deteriorated.

[0006]

In order to solve the above-mentioned problems, the present invention uses a pipe cooled by a Peltier element other than a Peltier element for cooling a semiconductor detector as a heat shield. The cooling efficiency of the semiconductor detector is improved, and the cooling temperature of the semiconductor detector is made as close as possible to the temperature of the uppermost stage of the Peltier element, thereby improving the performance as the detector.

[0007]

In the Peltier-cooled semiconductor detector configured as described above, the heat shield is cooled by a Peltier element other than the Peltier element for cooling the semiconductor detector, so that the cooling efficiency of the semiconductor detector is reduced. Is improved. Further, since the heat shield also functions as a cooling trap for the residual gas, the adsorption of the residual gas to the semiconductor detector and the FET can be considerably prevented. In addition, when the semiconductor detector is started, cooling of the heat shield is performed first, and cooling of the detector is performed later, so that adsorption of residual gas to the detector and the FET can also be prevented. Further, when the semiconductor detector is turned off, the same effect can be obtained by lowering the temperature of the detector first and then lowering the temperature of the heat shield.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, 1 is a semiconductor detector for detecting radiation, 2 is a first Peltier element for cooling the semiconductor detector 1, 3 is a heat sink for heat radiation of the first Peltier element 2, 4 is This is an ion pump for keeping the inside of the cryostat 5 at a high vacuum. Cryostat 5
Beryllium or polymer film (not shown)
Are attached as entrance windows. Reference numeral 6 denotes a cooling shaft for cooling the semiconductor detector 1 located at a position away from the first Peltier element 2. Reference numeral 7 denotes a heat shield, which is cooled by a plurality of Peltier elements 8 other than the first Peltier element 2 that cools the semiconductor detector 1.

This heat shield cooling Peltier element 8
A Peltier element having a lower number of stages than the first Peltier element 2 may be used. The heat shield 7 also serves as a cooling trap for the residual gas. Therefore, when the semiconductor detector is started, cooling of the heat shield 7 is performed first, and cooling of the detector 1 is performed later, so that adsorption of residual gas to the detector 1 and the FET can be further prevented. When the semiconductor detector is shut down,
A similar effect can be obtained by lowering the temperature of the detector first and then lowering the temperature of the heat shield.

Another embodiment of the present invention will be described with reference to FIG. In this case, the heat shield 7 is cooled by one heat shield cooling Peltier element 8 attached to the oblique heat sink 3. The reason for making the heat sink 3 slanted is to make the whole shape compact. The heat shield 7 and the heat shield cooling Peltier element 8 are connected by a copper thin plate or a copper stranded wire 10,
The heat shield 7 is fixed to the inner wall of the cryostat 5 by a plurality of support rings 9. The support ring 9 is made of silicon rubber or fluorine-based rubber and has a shape as shown in FIG.
Since only three protrusions are in contact with the inner wall of the cryostat 5, heat conduction is deteriorated, so that the heat shield can be sufficiently cooled.

Further, in the Peltier-cooled semiconductor detector having the above-described structure, when the semiconductor detector is started, it is possible to cool the heat shield first and then cool the detector. Further, in the Peltier-cooled semiconductor detector having the above-described structure, when the semiconductor detector is turned off, the temperature of the detector can be raised first, and the temperature of the heat shield can be raised later.

[0012]

As described above, according to the present invention, the cooling efficiency of the semiconductor detector is improved because the heat shield is cooled by the Peltier element other than the Peltier element for cooling the semiconductor detector. You. Further, since the heat shield also functions as a cooling trap for the residual gas, the adsorption of the residual gas to the semiconductor detector and the FET can be considerably prevented.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a main structure of a Peltier cooled semiconductor detector according to the present invention.

FIG. 2 is a cross-sectional view of a conventional Peltier cooled semiconductor detector.

FIG. 3 is a cross-sectional view of another conventional Peltier-cooled semiconductor detector.

FIG. 4 is a sectional view showing another embodiment of the present invention.

FIG. 5 is a plan view of a support ring.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor detector 2 1st Peltier element 3 Heat sink 4 Ion pump 5 Cryostat 6 Cooling shaft 7 Heat shield 8 Heat shield cooling Peltier element 9 Support ring 10 Copper thin plate or copper strand

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01T 1/24 H01L 35/28 H05G 1/26

Claims (1)

(57) [Claims] A semiconductor detector for detecting radiation;
Peltier element for cooling the semiconductor detector, heat sink for radiating the Peltier element, ion pump for keeping the inside of the cryostat at a high vacuum, cooling for cooling the semiconductor detector located away from the Peltier element A semiconductor detector having a shaft, wherein a heat shield surrounding a periphery of the semiconductor detector and the cooling shaft is cooled using a Peltier element other than a Peltier element for cooling the semiconductor detector. vessel.