JPH0635983U - Gas flow type proportional counter - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a gas flow type proportional counter having no gas leakage used in, for example, internal conversion electron Mossbauer spectroscopy. A main body 1A having an anode support base 3 for supporting an anode 4, a gas inlet, a gas outlet, and a window 5 for passing an incident γ-ray, and a main body 1A which is detachably attached to the main body 1A An outer lid 14 having an inner lid 16 that supports a sample table 17 on which S is placed, and a seal member 21 that is interposed between the main body 1A and the outer lid 14 to maintain airtightness. By configuring, it becomes possible to realize a counter tube without gas leakage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a gas flow type proportional counter.

[0002]

[Prior art]

 As is well known, the proportional counter is a detector that is widely used for measuring electromagnetic waves, and when detecting α-rays or electron beams with a small energy and therefore a short flight distance, place an anode near the sample. It is known that a gas flow type proportional counter, in which a sample is placed in the counter and a gas is allowed to flow from the outside, is suitable because it enables efficient counting when provided.

Such a gas flow type proportional counter (hereinafter, simply referred to as a counter tube) is composed of a casing-shaped main body 1 and a flat plate-shaped lid 2 as shown in FIG. Inside, an anode support base 3 made of an insulating material and an anode 4 stretched on the anode support base 3 and made of, for example, a stainless steel core wire with a diameter of 1.0 × 10 ⁻³ inch are housed. A window 5 is provided on the bottom surface 1a.

A cable 6 for applying a high voltage to the anode 4 and grounding the sample wall to be described later and the instrument wall 1b is connected to one wall (the instrument wall) 1b of the main body 1 via a high voltage connector 6a. A gas inlet 7 is provided, and a gas outlet 8 is provided on the other wall 1c. Further, the lid 2 is provided with a window 9 for passing incident γ rays, which is covered with a thin aluminum foil, for example, in a hole having a diameter of 0.5 inch.

In the conventional counter tube 10 thus configured, a sample (not shown) used for measurement is fixed to the window 5 with an adhesive tape or the like so that gas does not leak from the lower side of the window 5. It The sample is grounded together with the main body 1 through the cable 6 to form a cathode. In this state, the gas introduced from the gas inlet 7 fills the inside of the main body 1 and is then discharged from the gas outlet 8. A high voltage of about 1000 V is applied to the anode 4. In this case, α-rays and electron rays have a low transmittance in a substance, and therefore it is said that there must be no obstacle between the cathode 4 and the sample for their detection.

FIG. 10 shows an example in which the counter tube 10 is applied to internal conversion electron Mossbauer spectroscopy. That is, a wave height analyzer 11 and a counting device 12 are connected to a counter tube 10 to which a sample S is fixed, and is movably supported by a driving device such as a transducer through a window 9 of the counter tube 10. The sample S is irradiated with γ-rays from the radiation source 13. Then, the electrons emitted from the sample S according to their properties collide with the gas molecules to be amplified, detected as a pulse current by the wave height analyzer 11, and counted by the counter 12.

[0007]

[Problems to be solved by the device]

 However, the conventional counter tube 10 as described above has a simple structure, but in the method of using the adhesive tape to fix the sample S, the resistance to the pressure of the gas filled inside is weak in practice. However, there is a drawback that the adhesive tape is peeled off from the main body 1 and a gas leak is likely to occur from there, which causes a problem that the gas flow rate in the main body 1 is fluctuated or the gas outflow route is easily changed, which lowers the detection efficiency.

Therefore, as one of means for improving such a drawback, there is a counter tube in which the sample S is adhered to the inner wall of the main body 1 without the window 5 and the lid 2 is opened and closed every time the sample is exchanged. However, since such a counter tube has a structure in which a seal member such as an O-ring is sandwiched between the lid 2 and the main body 1 and the periphery is tightened with a screw or the like, the seal member is a seal member. Depending on the condition and the way of tightening the screws, a gap is created between the lid 2 and the main body 1 and gas leaks more easily, so it cannot be a drastic measure.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is possible to completely and easily prevent gas leakage from other than the gas outlet, and to optimize the inside of the main body. It is an object of the present invention to provide a gas flow type proportional counter capable of maintaining a high gas flow rate and outflow route and maximizing detection efficiency.

[0010]

[Means for Solving the Problems]

 The present invention includes a main body having an anode support base for supporting an anode, gas inflow / exhaust means, and a window for passing an incident γ ray, and an inside of a main body which is detachably attached to the main body and which supports an internal sample base. A gas flow type proportional counter comprising: an outer lid having a lid and a sealing member interposed between the main body and the outer lid to maintain airtightness.

The outer lid may be made of a flexible material, or a cylindrical lid is used instead of the inner lid, and the lid and the main body are sealed with each other. You may make it couple | bond detachably via.

[0012]

[Work]

 According to the present invention, since the main body of the counter tube and the outer lid or the lid can be detachably and airtightly connected, gas leakage can be easily and completely prevented. Further, if the outer lid is made of a flexible material, the sealing performance can be improved more easily.

[0013]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Embodiment 1] FIG. 1 is a perspective view showing an embodiment of the present invention, and FIG. 2 is a sectional view taken along the line AA. In these drawings, the same members as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted.

In the figure, 14 is a cylindrical outer lid having a bottom portion 14a, and an internal thread 15 is engraved in a predetermined range on the upper portion of the inner peripheral surface thereof. Reference numeral 16 denotes a disc-shaped inner lid provided on the bottom portion 14a of the outer lid 14. Reference numeral 17 is a disk-shaped sample table on which the sample S is placed. Reference numeral 18 denotes a circular collar provided in the lower portion of the main body 1A having a cylindrical shape, and an external thread 19 which is screwed with the female screw 15 of the outer lid 14 is engraved on the outer peripheral surface thereof.

Reference numeral 20 denotes a sealing groove provided on the lower surface of the collar 18, and a seal member 21 such as an O-ring is embedded so that a part thereof protrudes. The anode support 3 is fixed on the inner surface of the main body 1A to extend a plurality of anodes 4, and the outer surface thereof is provided with a window 5, a cable 6, a gas inlet 7, and a gas outlet 8 as in the conventional case. To be By configuring the counter tube 10A in this way, if the sample S is placed on the sample table 17 and then the male screw 19 of the main body 1A is screwed into the female screw 15 of the outer lid 14, it is as if it were a normal one. The sealing member 21 can be pressed and deformed by pressing the lower surface of the collar 18 against the upper surface of the inner lid 16 without the need for skill such as capping the bottle. As a result, the main body 1A is sealed by the inner lid 16, so that the gas introduced from the gas inlet 7 does not leak from any place other than the gas outlet 8 and is entirely discharged from the predetermined gas outlet 8. Can be made.

In the above embodiment, the outer lid 14 and the main body 1A have been described as being connected by screwing the female screw 15 and the male screw 19, but as shown in FIGS. 3 (a) and 3 (b), for example, as shown in FIG. For example, an L-shaped groove 22 may be formed in the brim 18 of the body 1A, and a protrusion 23 may be provided on the inner surface of the outer lid 14 for fitting. Further, the shape of the outer lid 14 is not limited to the above-mentioned embodiment, but the bottom center 14b may be hollowed out as shown in FIG. 5, for example.

Further, as the sealing member 21, other than the O-ring, for example, a highly ductile metal wire, oil, resin, or the like may be used. Second Embodiment FIG. 5 is a side sectional view showing a second embodiment. The outer lid 14A of the counter tube 10B is made of, for example, elastic rubber or a flexible material having a spring property, and the contracting force is used to bring the inner lid 16 and the brim 18 of the main body 1A into close contact with each other. . As a result, the gas in the main body 1A does not leak. Example 3 FIG. 6 is a side sectional view showing a third example. The lid 24 of the counter tube 10C is formed by forming the inner lid 16 of the first embodiment into a cylindrical shape and engraving a male screw 25 on the upper portion of the outer peripheral surface thereof. On the other hand, the main body 1B is not provided with the collar 18, and the female screw 26 is directly engraved on the upper portion of the wall thereof. As a result, the main body 1B and the lid 24 can be reliably coupled to each other via the seal member 21, so that the size is further reduced as compared with the first embodiment.

Instead of the male screw 25 and the female screw 26, as shown in FIGS. 7A and 7B, for example, an L-shaped groove 27 is bored in the instrument wall of the main body 1A, and the one lid 24 It is also possible to provide a protrusion 28 on the inner surface of and to fit them. Table 1 shows the experimental results of measuring the degree of gas leakage when the counter tube 10A of the first embodiment described above was applied to the internal conversion electron Mossbauer spectroscopy (see FIG. 10 above). For comparison, the measurement results of the conventional example with the highest degree of sealing are also shown in the same table. The gas used was a mixed gas of 96% He and 4% CH ₄ , and the energy of the irradiated γ rays was 14.4 kV.

[0019]

[Table 1]

As is clear from this table, the ratio of the amount of gas discharged from the gas outlet 8 to the amount of gas discharged from the gas inlet 7 was 90% in the case of the conventional example, but the present invention example Is 100%, which means that there is no leakage at all. In this experiment, the transition of the signal / time fluctuation situation when the sample S was repeatedly taken in and out of the counter tube is shown in FIG. 8 together with the conventional example. As is clear from this figure, the signal / time transition of the conventional example has large fluctuations, and it is impossible to detect when it is significant. You can see that you can get it.

Therefore, according to the present invention, it is obvious that gas leakage can be completely prevented without requiring skill, and as a result, the detection efficiency can always be maximized.

[0022]

[Effect of device]

 As described above, according to the present invention, since the main body of the counter tube and the lid can be airtightly coupled, it is possible to easily and completely prevent gas leakage, which results in detection efficiency. Can always be kept at the maximum, which contributes to the improvement of the accuracy of the counter tube.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 (a) is a partial side sectional view and FIG. 3 (b) is a BB arrow view showing another example of the connecting portion between the main body and the outer lid in the first embodiment of the present invention.

FIG. 4 is a side sectional view showing another example of the outer lid according to the first embodiment of the present invention.

FIG. 5 is a side sectional view showing a second embodiment of the present invention.

FIG. 6 is a side sectional view showing a third embodiment of the present invention.

7 (a) is a partial side sectional view and FIG. 7 (b) is a view taken in the direction of arrows CC, showing another example of the connecting portion between the main body and the outer lid in the second embodiment of the present invention.

FIG. 8 is a characteristic diagram showing the relationship between the number of times the counter tube is opened and closed and the signal / time.

FIG. 9 is a perspective view showing a conventional example of a counter tube.

FIG. 10 is a schematic diagram showing an application example of a gas flow type counter tube to internal conversion electron Mossbauer spectroscopy.

[Explanation of symbols]

 1 main body 3 anode support 4 anode 5 window 6 cable 8 gas outlet 9 gas inlet 10 counter 11 wave height analyzer 12 counter 13 gamma ray source 14 outer lid 15, 26 female screw 16 inner lid 17 sample stand 18 collar 19 , 25 Male screw 20 Sealing groove 21 Sealing member 22, 27 Groove 23, 28 Projection 24 Lid S Sample

Claims (3)

[Scope of utility model registration request] 1. A main body comprising an anode support for supporting an anode, a gas inflow / exhaust means, and a window for passing incident γ-rays, and a body detachably attached to the main body for supporting an internal sample base. A gas flow proportional counter comprising: an outer lid having a lid and a seal member interposed between the main body and the outer lid to maintain airtightness. 2. The gas flow proportional counter according to claim 1, wherein the outer lid is made of a flexible material. 3. The gas according to claim 1, wherein a lid formed in a cylindrical shape is used instead of the inner lid, and the lid and the main body are detachably coupled via a seal member. Flow type proportional counter.