JPS5829478B2 - gas flow counter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises: an anode wire is insulated and stretched in a metal container having a radiation entrance window; a counting gas is passed through the container;
The present invention relates to a gas flow counter in which a high voltage is applied between the container and an anode wire using the container as a cathode, and radiation incident on the container through an entrance window is counted.

In this type of conventional gas flow counter, the container is made of aluminum, and the anode wire is made of gold-plated tungsten wire, and a high voltage of 1000 to 2000 V is applied between the cathode and the anode wire, with the container as the cathode. A voltage is applied.

In that case, a counting gas is passed through the container, and the radiation that enters the container through the radiation entrance window is detected in the form of pulses by an anode beam.

As the counting gas, for example, PR gas (argon gas +
(methane gas), Q gas (helium gas + isobutane gas), propane gas, methane gas, etc. are used.

FIG. 1 is a longitudinal cross-sectional view of such a conventional gas flow counter, and FIG. 2 is a cross-sectional view thereof.

A plurality of anode wires 1 are insulated and stretched around the container 2.

This container 2 is made of aluminum and is used as a cathode.

At this time, this container 2 is grounded. On the other hand, the anode wire 1 is made of a gold-plated tungsten wire, and a high voltage H (V) is applied between the anode wire 1 and the container 2.

The container 2 is provided with a radiation entrance window 3 made of a thin film (for example, Mylar film).

4 and 41 are metal sleeves, and both ends of the anode wire 1 are connected to these metal sleeves 4 and 41 by solder bonding 10.

5 and 51 are insulators that insulate between the anode wire 1 and the container 2.

Reference numeral 6 denotes a fixing plate for fixing the entrance window 3 to the container 2, which is fixed to the container 2 by screws or the like (not shown).

7 is an O-ring.

In this way, the container 2 is configured as a closed container, into which counting gas is introduced from the gas port 8 and is led out via the gas outlet 9.

The radiation that has entered the container 2 through the entrance window 3 thus causes a discharge within the container 2 and is extracted from the anode wire 1 in the form of electrical pulses.

However, such conventional gas flow counters have the following drawbacks.

(1) Since the solder joint 10 and the insulators 5, 51 are exposed outside the container 2, they have the disadvantage that dew condensation occurs on their surfaces due to moisture in the external atmosphere, resulting in insulation deterioration.

If the number of 10 anode wires is 3, for example, there will be 6 adhesive portions 10 and insulators 5, 51, and therefore, as the number increases, the number of locations where insulation deterioration will occur also increases.

(2) If the anode wire 1 is disconnected for some reason, remove the radiation entrance window 3 and the fixing plate 6 from the container 2,
The broken anode wire 1 must be repaired or replaced.

However, even if the entrance window 3 is attached to the container 2 without bending when manufacturing a gas flow counter, once the entrance window 3 is removed in such a case, the thin film of the entrance window 3 will bend, and the gas This has the disadvantage of deteriorating the characteristics of the flow counter.

Furthermore, this also applies to the removal of the entrance window 3 when cleaning the inside of the container 2.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide a gas flow counter in which the above-mentioned drawbacks are eliminated.

According to the present invention, such a purpose is achieved by: a metal bottom plate, two insulating supports fixed to the bottom plate at a predetermined interval, and a plurality of metal pieces supported by these supports, respectively. a plurality of anode wires each having both ends joined to a sleeve made of plastic and stretched between the supports; an annular frame body removably attached to the bottom plate so as to surround the support body; and a bottom plate of the annular frame body. and a radiation entrance window attached to the opposite end of the window, and a lead wire connected to each of the anode wires, and a high voltage is applied to the lead wire, and the base plate, the frame body, and the radiation entrance window This is done by passing a counting gas through a closed container.

According to one preferred embodiment of the invention, the counting gas is passed into the closed container via gas inlets and gas outlets provided in the bottom plate.

According to another preferred embodiment of the invention, the application of the high voltage is carried out by means of a power supply line connected to the lead wire via an insulating bushing provided in the base plate.

The present invention will be described in detail below with reference to the drawings.

FIG. 3 is a longitudinal sectional view of an embodiment of the present invention, FIG. 4 is a cross-sectional view thereof, FIG. 5 is a plan view of an embodiment of the invention with the entrance window removed, and FIG. It is a detailed diagram of the main part.

In the present invention, the closed container 20 constituting the gas flow counter mainly includes a metal bottom plate 21.
A metal annular frame 22 is attached to the frame 22 by a plurality of screws, such as screws 281, 282, and 283, and a radiation entrance window 3 is fixed to the frame 22 by a fixing plate 6.

Note that the fixing plate 6 has a plurality of screws, for example, screws 291, 2.
It is attached to the frame body 22 by 92°293.

O-IJ grooves 24 and 25 are formed on the lower and upper surfaces of the frame body 22, respectively, and these O-ring grooves 24,
O-rings 26 and 27 are fitted into each of 25 and 25, respectively.

Further, screws 281 and 282 are provided on the lower and upper surfaces of the frame 22 on the outside of the 0-IJ song grooves 4 and 25, respectively.
, 283 and screw holes for screws 29L292, 293 are drilled.

As the screw holes, in FIG. 5, a plurality of screw holes 60 are shown on the upper surface of the frame 22.

Insulating supports 23.2 are mounted on the bottom plate 21 at predetermined intervals.
30 is fixed.

That is, the insulating support 23 has, for example, two screws (however, only the screw 300 is shown).

) are respectively cylindrical spacing pieces (however, only spacing piece 310 is shown).

) is fixed to the bottom plate 21 via.

Note that 320°323 is a nut.

On the other hand, the insulating support 230 has two screws 301, for example.
．． 320 are fixed to the bottom plate 21 via cylindrical spacing pieces 311 and 312, respectively.

Note that 32L322 is a nut.

A plurality of through holes are provided in each of the insulating supports 23 and 230, and as an example is shown in FIG. 6, a metal sleeve 4 is fitted into each of the through holes.

One end of each anode wire 1 is joined to the respective sleeve 4 by solder bonding 10 via a coil spring 37 and a nickel wire 40, and thereby an insulating support 2
3, and the other end is joined to each sleeve 4 by solder bonding 10 via a nickel wire 40, thereby being fixed to an insulating support 230.

By using the coil spring 3T, the tension of the anode wire 1 can be kept constant, thereby allowing the counter to operate stably.

Furthermore, each anode wire 1 is connected to a lead wire 36 on the insulating support 230 side, and this lead wire 36 is connected to a power supply line 34 via a resistor 35 and an insulating bushing 33.

In addition, the bottom plate 21 has a counting gas population 8 and a gas outlet 9.
This bottom plate 21 is grounded, and a high voltage is applied to each anode wire 1 via a power supply line 34.

Next, an example of assembling the above configuration will be described.

Two insulating supports 23, 230 are fixed to the bottom plate 21 with screws 300, 301, 302, etc.

Thereafter, the anode wires 1 are soldered to the metal sleeves 4 of the supports 23 and 230, respectively.

Thereafter, the IJ-domain wire 36 is similarly soldered to the anode wire 1 and connected to the power supply line 34 via the resistor 35 and the insulating bush 33.

On the other hand, the metal frame 22 has an O-'J groove 25.
-' Fit the J song 7, and then fix the radiation entrance window 3 without bending with the fixing plate 6 and screws 291, 292, 293, etc.

Thereafter, the 0-'J song 6 is fitted into the 0-'J song groove 4 of the frame 22, and the frame 22 is fixed to the bottom plate 21 with screws 281, 282, 283, etc.

In this way, a gas flow counter is constructed.

As described above, the gas flow counter according to the present invention includes a metal bottom plate 21, two insulating supports 23 and 230 fixed to the bottom plate at a predetermined distance,
A plurality of anode wires 1 are connected at both ends to a plurality of metal sleeves respectively supported by these supports and stretched between the supports, and are removably attached to the bottom plate so as to surround the supports. the attached annular frame 22;
A radiation entrance window 3 is attached to the end of the annular frame opposite to the bottom plate, and a lead wire 36 is connected to each of the anode wires.
The apparatus is characterized in that a high voltage is applied to the lead wire, and a counting gas is caused to flow through a closed container constituted by the bottom plate, the frame, and the radiation entrance window.

Therefore, according to the present invention, the following effects are achieved.

(1) The joint between the metal sleeve 4 and the anode wire 1 (in the illustrated embodiment, the solder joint 10) and the insulating supports 23 and 230 that support the metal sleeve 4 are connected to the bottom plate 21. Since it is placed in the closed container 20 constituted by the annular frame 22 and the radiation entrance window 3, it is always surrounded by dry counting gas and is not affected by the moisture in the external atmosphere.

Therefore, it is very preferable in terms of insulation performance.

Although the illustrated embodiment uses solder bonding 10 to connect the metal sleeve 4 and the anode wire 1, for example, the sleeve 4 and the anode wire 1 may be connected by caulking, spot welding, or screwing. It is also possible to use bonding means such as, and is not limited to solder bonding.

(2) If the anode wire 1 is disconnected for some reason, or if you want to clean the inside of the sealed container 20,
Since the annular frame 22 is removably attached to the bottom plate 21, the frame 22 and the bottom plate 21 are separated, and then the broken anode wire is repaired or replaced, or cleaned.

At this time, since the radiation entrance window 3 remains fixed to the frame 22, no bending occurs.

In addition, the mounting means for removably mounting the annular frame 22 on the bottom plate 21 are screws 281 and 28 in the illustrated embodiment.
Although the case where a No. 2,283 screw is used has been described, for example, a clamp or the like can also be used, and the screw is not limited to the screw.

[Brief explanation of drawings]

Fig. 1 is a schematic vertical cross-sectional view of a conventional gas flow counter, Fig. 2 is a schematic cross-sectional view thereof, Fig. 3 is a schematic vertical cross-sectional view of an embodiment of the present invention, and Fig. 4 is a schematic cross-sectional view thereof. , FIG. 5 is a plan view of the main part, and FIG. 6 is a sectional view of the main part. 1... Anode ray, 3... Radiation entrance window,
20... Airtight container, 21... Bottom plate, 2
2...Frame, 23°230...Support, 26,27...0-IJ song 281.28
2,283,291.292゜293.300,301
．． 302...Screw, 33...Insulating bushing 36...Lead wire.

Claims (1)

[Claims] 1. A metal bottom plate 21, two insulating supports 23, 230 fixed to the bottom plate at a predetermined interval, and a plurality of metal supports supported by these supports, respectively. A plurality of anode wires 1 each having both ends connected to a sleeve and stretched between the supports; an annular frame 22 removably attached to the bottom plate so as to surround the supports; It includes a radiation entrance window 3 attached to the end opposite to the bottom plate, and a lead wire 36 connected to each of the anode wires, and a high voltage is applied to the lead wire, and the bottom plate, the frame body and the radiation A gas flow counter characterized in that a counting gas is passed through a closed container formed by an entrance window. 2. In the counter according to claim 1, the counting gas is caused to flow through the closed container 20 through the gas port 8 and the gas outlet 9 provided in the bottom plate 21. counter. 3. In the counter according to claim 1 or 2, the application of high voltage is performed by a power supply line 34 connected to a lead wire 36 via an insulating bush 33 provided on the bottom plate 21. Gas flow counter with unique features.