JPH02129582A - Exo-electron dosimeter reader - Google Patents

Abstract

PURPOSE:To prevent the surface of the exo-electron dosimeter from wearing and to obtain reproducibility by providing a multi-core gas proportional counter tube consisting of a 1st anode core group parallel to a sample surface and a 2nd anode core group parallel to the anode core group. CONSTITUTION:Information on radiation and absorbed-beam dosages stored in the exo-electron dosimeter appears as the emission of exo-electrons in counted gas 5 by a halogen lamp 1. A proper potential gradient is generated between the dosimeter 2 and 1st anode cores 3 to form the drift space of the exo- electrons. Exo-electrons passed through this drift space are accelerated by an electric field produced by the 1st and 2nd anode cores 3 and 4 to cause an electron avalanche. Ions generated in a gas amplification area where the electron avalanche is caused are acquired by the cores 3. Therefore, there is no ion shock to the surface of the dosimeter 2 to reduce the wear of the surface of the dosimeter 2, and no positive potential is generated on the surface, so the reproducibility is excellent.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an exoelectron detection section of an exoelectron dosimeter reading device.

[Conventional technology]

FIG. 3 is a conceptual diagram showing the conventional exoelectron dosimeter reading device Ut described in "Applied Physics" Vol. 55, No. 5, page 443. In the figure, 111 is a halogen lamp, 12
( is the exo electron dose needle, +41 is the anode core wire, (8) is the anode core wire (high voltage power supply for 41, +9) is the anode ° core wire 141
．． It is a preamplifier that amplifies the output of a proportional counter consisting of a counting gas, 51, @ pole tlol.

61 is a gas introduction hole.

Next, the operation will be explained. The surface of the exoelectron dosimeter 12) is coated with an exoelectron emitting material such as BeO. When radiation such as lζx@, r m eβ rays is incident on this surface, information on the absorbed dose is stored.

Exo electron dosimeter 12) that has information on this absorption 4iAt
is placed as shown in FIG. 3 and heated by a halogen lamp III K, so that exoelectrons are emitted into the proportional counter tube. These exoelectrons are amplified and polarized by applying a high voltage to the anode core wire 141, and are further amplified by the preamplifier (9). and measure.

[Problem to be solved by the invention]

Since the conventional exoelectron dosimeter reading device was configured as described above, the counting gas undergoes ionization and the ions generated hit the exoelectron dosimeter surface, causing wear and tear on the exoelectron 1tAll meter surface and positive potential. There was a problem in that the measurement value fluctuated due to the formation of .

This invention was made to solve the above-mentioned problems, and aims to prevent the surface of an exoelectron dosimeter from being worn out and to provide an exoelectron dosimeter reading device with reproducibility.

[Means for solving problems]

The exo-electron dose needle reading device according to the present invention has a plurality of anode core lines of '4IJ1 arranged in parallel on the surface of an exo-electron dosimeter, and a large number of eleventh anode cores 1i arranged in parallel on the first anode core line surface. Exo electrons are detected using a core gas proportional counter tube.

[Effect]

The exoelectron dosimeter reading device in this invention is the first
By providing a multi-core gas proportional counter composed of a third anode core wire and a third anode core wire, the surface of the exoelectron dosimeter can be protected and its reproducibility can be improved.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 111 is a halogen lamp, a 21-digit exoelectron dosimeter, and 31 and 141 are the @1 and second anode core wires parallel to the surface of the exoelectron dosimeter.

(61 is a cathode (gas inlet provided in one item of 101,
+61 is the counting gas introduced from the gas inlet (6).

FIG. 3 is an explanatory diagram showing the fet right arrangement and the measurement circuit when viewed from the gas inlet (6) side of FIG. 1. 171 and 1g+
The high-voltage power supply for the first and fourth anodes (9) is the front cover amplifier 4 connected to the 8th anode core II 141.

Next, the operation will be explained. The radiation/absorption radiation sensitivity information stored in the exoelectron dosimeter 121 appears as exoelectron emission in the counting gas tlsl by the halogen lamp tl+.

By creating an appropriate potential gradient between the exoelectron dosimeter 121 and the first anode core wire 131, an exoelectron drift space is formed (gas amplification does not occur in this space). The exoelectrons that have passed through the entire drift space are accelerated by the electric fields created by the first and eighth anode core wires 131141, causing an electron avalanche.

On the other hand, ions generated in the gas amplification region where the tt avalanche occurs are captured by the first anode core wire. Therefore, there is no ion bombardment on the surface of the dosimeter, and there is less wear on the surface of the exoelectron dosimeter. Furthermore, since no positive potential is formed on the surface, reproducibility is improved.

Exo electrons amplified in the gas amplification region are further preamplified! It is amplified by +91.

In the above embodiment, a case is shown in which a large number of core wires are used as the anode core wire (3) of i@1, but the same effect can be obtained even if this is replaced with a mesh.

〔Effect of the invention〕

As described above, according to the VC of the present invention, a multi-core wire gas proportional counter tube equipped with the first and second anode core collars is used in the exoelectron detection section of the exoelectron at meter reading device, so that the surface of the exoelectron dosimeter is It has the advantage of being able to provide an exoelectron dosimeter reading device that does not wear out and has good reproducibility in detecting exoelectrons.

[Brief explanation of drawings]

Figure 1 is a front view of the installation of an exoelectron dosimeter reading device according to part N III of this invention, Figure 8 is an explanatory diagram showing the electrode part and circuit configuration of Figure @1, and Figure 3 is a conventional exoelectron dosimeter reading device. It is an installation front view of a meter reading device. In the figure, 131 is the first anode core wire, (4I is the eighth anode core l!
shows. In addition, in the figures, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] An exoelectron dose characterized by using a multicore gas proportional counter tube configured of a first anode core wire group parallel to the sample surface and a second anode core wire group parallel to the first anode core wire group. Meter reading device.