JP2935362B1 - Radiation measurement device - Google Patents

Abstract

An object of the present invention is to perform high-sensitivity measurement with a simple configuration without leak current flowing between electrodes even when humidity is high. SOLUTION: The left and right conductive plates, which are vertically suspended in parallel at a certain distance from each other, are grounded via an ammeter and the right flat plate is grounded as it is. The left and right center plates are connected to the battery so that the left center plate serves as the anode, and are interposed in parallel with the left and right plates, respectively. The two left and right central flat plates are a radiation measurement device in which both batteries are floated in the air by magnetic levitation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation measuring apparatus capable of determining a radiation dose and a radioactivity concentration by directly measuring an ionization current with high sensitivity even in an atmosphere of high humidity.

[0002]

2. Description of the Related Art Conventionally, an ionization chamber has been known as a radiation measuring apparatus. Further, as a device which is improved to detect even weak radiation, for example, Japanese Patent Application Laid-Open No. H08-2111
There is an apparatus as disclosed in Japanese Patent Application Publication No. 57-57.

[0003]

In a conventional ionization chamber, if the humidity is high, a leak current flows between the electrodes, making measurement impossible. In the apparatus disclosed in Japanese Patent Application Laid-Open No. H8-212157,-ions ionized by radiation are adsorbed to a magnetically floating electrode charged to +, and a terminal is brought into contact with this electrode from the outside to reduce the charge. Therefore, there is a problem that the device is complicated and a leak current flows because the terminal is contacted from the outside.

An object of the present invention is to provide a radiation measuring apparatus in which a leak current does not flow between electrodes even when humidity is high, and which can perform highly sensitive measurement with a simple configuration.

[0005]

In order to achieve the above object, in the radiation measuring apparatus according to the first aspect of the present invention, the left and right conductive flat plates vertically suspended at a certain interval are provided on the left side. The flat plate is grounded via an ammeter, the right flat plate is grounded as it is, two conductive left and right central flat plates are connected between the left and right conductive flat plates, and the battery is connected so that the left central flat plate becomes the anode. A parallel plate type radiation measuring device in which the left and right central flat plates are interposed in parallel with the left and right conductive flat plates, and the two left and right center flat plates are both floated in the air by magnetic levitation.

According to a second aspect of the present invention, in the radiation measuring apparatus, the conductive outer cylindrical body is grounded via an ammeter, and the conductive inner cylindrical body is placed inside the conductive outer cylindrical body. The conductive rod is disposed so as to be coaxial with the conductive outer cylinder, and a conductive rod is disposed inside the conductive inner cylinder while being insulated from the conductive inner cylinder, and is disposed so as to be coaxial with the conductive inner cylinder. The conductive inner cylindrical body and the conductive rod body are a cylindrical radiation measuring apparatus in which both the batteries are floated in the air by magnetic levitation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for an understanding of the present invention.
FIG. 1 is a principle view of a parallel plate type radiation measuring apparatus according to a first embodiment of the present invention, in which left and right conductive flat plates 1 and 2 are vertically suspended in parallel at a certain interval. The left flat plate 1 is grounded via an ammeter 3, and the right flat plate 2 is grounded as it is. Under the condition that two conductive left and right central flat plates 4 and 5 are connected to the battery 6 such that the left central flat plate 4 functions as an anode between the left and right conductive flat plates 1 and 2, The left and right central flat plates 4, 5 and the battery 6 are all levitated in the air by magnetic levitation.

When the radiation is passed through the above-mentioned parallel plate type radiation measuring apparatus, the radiation ionizes the air, and the ionized ions are collected between the left flat plate 1 and the left central flat plate 4 and connected to the left flat plate 1. The ionization current can be measured by the measured ammeter 3. The potential between the plates of the left flat plate 1 serving as a collecting electrode and the left central flat plate 4 serving as a high-voltage electrode is generated by applying a voltage to the electrodes of the floating left and right center flat plates 4 and 5. That is, in the device using the magnetic levitation electrodes, a potential is indirectly generated between the left flat plate 1 and the left central flat plate 4 by electrostatic induction by applying a voltage to the electrodes floating in the air. With this potential, ions between the left flat plate 1 and the left flat plate 4 are collected, and an ionization current is collected. In this method, there is no leakage current that occurs in the insulator between the electrodes as occurs in a conventional electrode box that directly applies a voltage to the electrodes.
Even in an atmosphere of high humidity, it is possible to directly measure the ionization current with high sensitivity.

FIG. 2 is a principle diagram of a cylindrical radiation measuring apparatus according to a second embodiment of the present invention. A conductive outer cylindrical body 11 is grounded via an ammeter 12, and a conductive The conductive inner cylindrical body 13 is disposed so as to be coaxial with the conductive outer cylindrical body 11. Further, a conductive rod 14 is disposed further inside the conductive inner cylindrical body 13 so as to be coaxial with the conductive inner cylindrical body 13 while being electrically insulated from the conductive inner cylindrical body 13. Have been. The conductive inner cylindrical body 13 and the conductive rod body 14 are connected to a battery 15 such that the conductive inner cylindrical body 13 serves as an anode.
Moreover, the conductive inner cylinder 13 and the conductive rod 14
The batteries 15 are all levitated in the air by magnetic levitation.

When the radiation is passed through the cylindrical radiation measuring apparatus having the above-described configuration, the radiation ionizes the air, and the ionized ions are transferred to the conductive outer cylinder 11 and the conductive inner cylinder 1.
The ionization current can be measured by an ammeter 12 collected between 3 and connected to the conductive outer cylinder 11. Also in the case of the second embodiment, since a voltage is applied to the electrode floating in the air, there is no generation of a leak current as in the first embodiment.

[0011]

As described above, according to the present invention,
Since the battery and the electrode to which the voltage is applied are levitating in the air by magnetic levitation, the collector electrode for collecting the ionization current is separated from the high-voltage electrode, eliminating the leakage current flowing into the ammeter, and ensuring insulation. Extremely high. Therefore, there is an effect that stable measurement with high sensitivity can be realized even in a high humidity atmosphere that is critical for the ionization chamber.

[Brief description of the drawings]

FIG. 1 is a principle diagram of a first embodiment.

FIG. 2 is a principle diagram of a second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Left conductive plate 2 Right conductive plate 3 Ammeter 4 Left center plate 5 Right center plate 6 Battery 11 Conductive outer cylinder 12 Ammeter 13 Conductive inner cylinder 14 Conductive rod 15 Battery

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01J 47/00-47/26 G01T 1/185

Claims (2)

(57) [Claims] 1. The left and right conductive plates, which are vertically suspended in parallel at a certain interval, are grounded via an ammeter, and the right side plate is grounded as it is, between the left and right conductive plates. Two conductive left and right central flat plates are interposed in parallel with the left and right conductive flat plates, respectively, with the left central flat plate connected to the battery such that the left central flat plate serves as an anode. A radiation measuring device characterized by being levitated in the air by magnetic levitation. 2. A conductive outer cylinder is grounded via an ammeter, and a conductive inner cylinder is disposed inside the conductive outer cylinder so as to be coaxial with the conductive outer cylinder. Inside the conductive inner cylinder, a conductive rod is disposed insulated from the conductive inner cylinder so as to be coaxial with the conductive inner cylinder, and the conductive inner cylinder and the conductive The conductive rod is connected to the battery so that the conductive inner cylinder becomes an anode, and the conductive inner cylinder and the conductive rod are both floated in the air by magnetic levitation. apparatus.