JP5082684B2 - Peltier cooling type semiconductor X-ray detector - Google Patents

Description

  The present invention relates to a Peltier-cooled semiconductor X-ray detector, and more particularly, in a Peltier-cooled semiconductor X-ray detector equipped with an ion pump, even if the pressure in the vacuum vessel rises above the ion pump starting pressure. The present invention relates to a Peltier-cooled semiconductor X-ray detector capable of easily starting an ion pump.

Conventionally, a semiconductor X-ray detection sensor for X-ray detection, a Peltier element for electronically cooling the semiconductor X-ray detection sensor, a vacuum container for housing the semiconductor X-ray detection sensor and the Peltier element, An X-ray detector including a vacuum pump for making a vacuum is known (for example, see Patent Document 1).
JP 2005-308632 A

In a Peltier-cooled semiconductor X-ray detector that cools a semiconductor X-ray detection sensor with a Peltier element, when the degree of vacuum in the vacuum vessel decreases, the cooling capacity of the Peltier element decreases and the temperature of the semiconductor X-ray detection sensor rises. Detection performance decreases. Therefore, the conventional X-ray detector includes a vacuum pump to maintain a high vacuum.
As this vacuum pump, it is preferable to use an ion pump because it is free from vibration and is compact.
However, if the Peltier-cooled semiconductor X-ray detector is not used for a long period of time, the gas is released inside the vacuum vessel or enters from the outside. ), The ion pump cannot be started, and as a result, the Peltier-cooled semiconductor X-ray detector cannot be used.
Therefore, an object of the present invention is to make it possible to easily start the ion pump even if the pressure in the vacuum vessel is higher than the starting pressure of the ion pump in the Peltier cooled semiconductor X-ray detector provided with the ion pump. The object is to provide a Peltier cooled semiconductor X-ray detector.

In a first aspect, the present invention provides a semiconductor X-ray detection sensor for X-ray detection, a Peltier element for electronically cooling the semiconductor X-ray detection sensor, the semiconductor X-ray detection sensor, and the Peltier element. A Peltier device comprising: a vacuum container to be housed; an ion pump for making the inside of the vacuum container a high vacuum; and a means for cooling the inside of the vacuum container to make the inside of the vacuum container not more than an ion pump starting pressure. A cooled semiconductor X-ray detector is provided.
In the Peltier-cooled semiconductor X-ray detector using the Peltier-cooled semiconductor X-ray detector according to the first aspect, the vacuum vessel cooling means is operated even if the pressure in the vacuum vessel rises above the ion pump starting pressure. By doing so, the gas in the vacuum vessel can be cold trapped, and the pressure in the vacuum vessel can be made lower than the ion pump starting pressure. Accordingly, the ion pump can be started, and the pressure in the vacuum vessel can be set to a necessary high vacuum.
Since the vacuum container cooling means only needs to be used when the pressure in the vacuum container is lower than the ion pump starting pressure, the use of the vacuum container cooling means is limited to an emergency and the running cost can be suppressed.

In a second aspect, the present invention provides the Peltier-cooled semiconductor X-ray detector according to the first aspect, wherein the vacuum vessel cooling means is a liquid nitrogen trap.
In the Peltier-cooled semiconductor X-ray detector according to the second aspect, even if the pressure in the vacuum vessel rises above the ion pump starting pressure, the gas in the vacuum vessel is changed by putting liquid nitrogen into the liquid nitrogen trap. It is possible to trap the pressure inside the vacuum vessel to be lower than the ion pump starting pressure. Accordingly, the ion pump can be started, and the pressure in the vacuum vessel can be set to a necessary high vacuum.
In addition, since it is sufficient to use a liquid nitrogen trap only when the pressure in the vacuum vessel is lowered below the ion pump starting pressure, the use of liquid nitrogen is limited to an emergency, and the amount used can be reduced, and the running cost can be suppressed. .

In a third aspect, the present invention provides the Peltier-cooled semiconductor X-ray detector according to the first aspect, wherein the vacuum container cooling means is a refrigerator connecting means.
In the Peltier-cooled semiconductor X-ray detector according to the third aspect, when the pressure in the vacuum vessel rises above the ion pump starting pressure and the ion pump cannot be started, it can be cooled to the liquid nitrogen temperature. By connecting the refrigerator from the outside and cooling the refrigerator connection port in the vacuum vessel, the gas in the vacuum vessel can be cold trapped, and the pressure in the vacuum vessel can be made lower than the ion pump starting pressure. Accordingly, the ion pump can be started, and the pressure in the vacuum vessel can be set to a necessary high vacuum.

In a fourth aspect, the present invention relates to a Peltier cooling characterized in that, in the Peltier cooling type semiconductor X-ray detector according to the third aspect, an adsorbent is attached to a part of a refrigerator connection port in the vacuum vessel. A type semiconductor X-ray detector is provided.
In the Peltier-cooled semiconductor X-ray detector according to the fourth aspect, since the adsorbent adsorbs the gas in the vacuum vessel, the pressure increase in the vacuum vessel can be suppressed. Further, when the liquid nitrogen trap is operated, the adsorbent is cooled by the liquid nitrogen trap and adsorbs the gas with high efficiency.

  According to the Peltier-cooled semiconductor X-ray detector of the present invention, an ion pump can be used as a vacuum pump, and even if the pressure in the vacuum vessel rises higher than the ion pump starting pressure, the ion pump can be easily It can be started.

  Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited thereby.

FIG. 1 is a schematic cross-sectional view illustrating a configuration of a Peltier-cooled semiconductor X-ray detector 100 according to the first embodiment.
The Peltier-cooled semiconductor X-ray detector 100 includes a semiconductor X-ray detection sensor 2 for detecting X-rays incident from the window 1, an FET 3 for amplifying the output signal of the semiconductor X-ray detection sensor 2, and a semiconductor X-ray. Heat transfer member 4 and multistage Peltier element module 5 for cooling detection sensor 2 and FET 3, heat sink 6 for exhausting heat from multistage Peltier element module 5, semiconductor X-ray detection sensor 2, multistage Peltier element module 5 and the like A vacuum vessel 7 for storing the vacuum vessel, an ion pump 8 for maintaining the degree of vacuum of the vacuum vessel 7 at a high vacuum, a liquid nitrogen trap 9 for reducing the inside of the vacuum vessel 7 to an ion pump starting pressure or lower, and a liquid nitrogen trap 9 and an adsorbent 10 attached to a portion in the vacuum vessel 7. The liquid nitrogen trap 9 corresponds to the vacuum container cooling means in the present invention.

The semiconductor X-ray detection sensor 2 is a Si (Li) element. A PIN diode, an SDD (Silicon Drift Detector) , a high purity silicon element, or a high purity germanium element may be used.

  The adsorbent 10 is activated carbon. Other adsorbents such as carbon, silica, and alumina may be used. In addition, the material and structure of the adsorbent can be variously changed as long as it has a function of capturing the substance remaining in the vacuum vessel.

  When the Peltier-cooled semiconductor X-ray detector 100 is assembled, the parts that have been previously baked are assembled and then evacuated while being baked, and sealed at a predetermined degree of vacuum.

According to the Peltier cooling type semiconductor X-ray detector 100 of the first embodiment, the following effects can be obtained.
(1) A small ion pump without vibration can be used.
(2) Even if gas is released inside the vacuum vessel 7 or gas enters from the outside, it is adsorbed by the adsorbent 10 contained in the vacuum vessel 7, thereby slowing down the degree of vacuum over time. I can do it.
(3) Even if the pressure in the vacuum vessel 7 rises above the ion pump starting pressure, the ion pump 8 can be easily started by putting liquid nitrogen N in the liquid nitrogen trap 9 to be equal to or lower than the ion pump starting pressure. it can.
(4) When the liquid nitrogen trap 9 is operated, the adsorbent 10 is cooled by the liquid nitrogen trap 9 and adsorbs the gas with high efficiency. Therefore, the pressure in the vacuum vessel 7 is lowered to the ion pump starting pressure or lower. Increases nature.

FIG. 2 is a schematic cross-sectional view illustrating a configuration of a Peltier-cooled semiconductor X-ray detector 200 according to the second embodiment.
The Peltier cooled semiconductor X-ray detector 200 includes a semiconductor X-ray detection sensor 2 for detecting X-rays incident from the window 1, an FET 3 for amplifying an output signal of the semiconductor X-ray detection sensor 2, and a semiconductor X-ray. Heat transfer member 4 and multistage Peltier element module 5 for cooling detection sensor 2 and FET 3, heat sink 6 for exhausting heat from multistage Peltier element module 5, semiconductor X-ray detection sensor 2, multistage Peltier element module 5 and the like A vacuum vessel 7 for storing the vacuum vessel, an ion pump 8 for maintaining the vacuum degree of the vacuum vessel 7 at a high vacuum, a refrigerator connection port 20 for making the inside of the vacuum vessel 7 equal to or lower than the ion pump starting pressure, and a refrigerator And an adsorbent 21 attached to a portion of the connection port 20 in the vacuum vessel 7. The refrigerator connection port 20 corresponds to the vacuum container cooling means in the present invention.

  The semiconductor X-ray detection sensor 2 is a Si (Li) element. A PIN diode, an SDD (Silicon Drift Detector), a high-purity silicon element, or a high-purity germanium element may be used.

  The adsorbent 21 is activated carbon. Other adsorbents such as carbon, silica, and alumina may be used. In addition, the material and structure of the adsorbent can be variously changed as long as it has a function of capturing the substance remaining in the vacuum vessel.

  When assembling the Peltier-cooled semiconductor X-ray detector 200, after assembling parts that have been baked in advance, the parts are evacuated while being baked and sealed at a predetermined degree of vacuum.

According to the Peltier-cooled semiconductor X-ray detector 200 of the second embodiment, the following effects can be obtained.
(1) A small ion pump without vibration can be used.
(2) Even if gas is released inside the vacuum vessel 7 or gas enters from the outside, it is adsorbed by the adsorbent 21 contained in the vacuum vessel 7, thereby slowing down the degree of vacuum over time. I can do it.
(3) Even if the pressure in the vacuum vessel 7 rises above the ion pump starting pressure, the refrigerator 23 that can be cooled to the liquid nitrogen temperature is connected from the outside, and the refrigerator connection port 20 in the vacuum vessel is cooled. Thus, the ion pump 8 can be easily started by trapping the gas in the vacuum vessel and setting the ion pump starting pressure or lower.
(4) When a refrigerator that can be cooled to liquid nitrogen temperature is connected from the outside and the refrigerator connection port 20 in the vacuum vessel is cooled, the adsorbent 21 is cooled, and gas is adsorbed with high efficiency. The reliability of lowering the pressure in the vacuum vessel 7 to be lower than the ion pump starting pressure is increased.

  Although Embodiments 1 and 2 of the present invention have been described above, other known cooling means are appropriately used as the cooling means in the vacuum container according to the present invention as long as it has a function of setting the inside of the vacuum container to the ion pump starting pressure or lower. It can be adopted.

  The Peltier-cooled semiconductor X-ray detector of the present invention can be used as a detector for an energy dispersive X-ray analyzer.

1 is a schematic cross-sectional view showing a Peltier-cooled semiconductor X-ray detector according to Example 1. FIG. 6 is a schematic cross-sectional view showing a Peltier-cooled semiconductor X-ray detector according to Embodiment 2. FIG. 6 is a schematic cross-sectional view showing a Peltier-cooled semiconductor X-ray detector according to Embodiment 2. FIG.

Explanation of symbols

1 Window 2 Semiconductor X-ray detection sensor 3 FET
4 Heat transfer member 5 Multi-stage Peltier element module 6 Heat sink 7 Vacuum vessel 8 Ion pump 9 Liquid nitrogen trap 10 Adsorbent 20 Refrigerator connection port 23 Refrigerator 100, 200 Peltier cooled semiconductor X-ray detector

Claims (3)

A semiconductor X-ray detection sensor for X-ray detection, a Peltier element for electronically cooling the semiconductor X-ray detection sensor, a vacuum container for housing the semiconductor X-ray detection sensor and the Peltier element, and the inside of the vacuum container A Peltier-cooled semiconductor X-ray detector comprising: an ion pump for making a high vacuum in the vacuum vessel; and a vacuum vessel cooling means for setting the inside of the vacuum vessel to an ion pump starting pressure or lower , The Peltier cooling type semiconductor X-ray detector, wherein the cooling means is a liquid nitrogen trap. A semiconductor X-ray detection sensor for X-ray detection, a Peltier element for electronically cooling the semiconductor X-ray detection sensor, a vacuum container for housing the semiconductor X-ray detection sensor and the Peltier element, and the inside of the vacuum container A Peltier-cooled semiconductor X-ray detector comprising: an ion pump for making a high vacuum in the vacuum vessel; and a vacuum vessel cooling means for setting the inside of the vacuum vessel to an ion pump starting pressure or lower, The Peltier cooling type semiconductor X-ray detector, wherein the cooling means is a refrigerator connecting means. 3. The Peltier cooling type semiconductor X-ray detector according to claim 1, wherein an adsorbent is attached to a portion in the vacuum vessel of the vacuum vessel cooling means. 4. Semiconductor X-ray detector.

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