JP2002014171A - HIGH-PERFORMANCE He-3 COUNTER FOR NEUTRON - Google Patents
HIGH-PERFORMANCE He-3 COUNTER FOR NEUTRONInfo
- Publication number
- JP2002014171A JP2002014171A JP2000237735A JP2000237735A JP2002014171A JP 2002014171 A JP2002014171 A JP 2002014171A JP 2000237735 A JP2000237735 A JP 2000237735A JP 2000237735 A JP2000237735 A JP 2000237735A JP 2002014171 A JP2002014171 A JP 2002014171A
- Authority
- JP
- Japan
- Prior art keywords
- neutron
- counter
- electrodes
- anode
- cations
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Abstract
Description
【０００１】[0001]
【発明が属する技術分野】本発明は、放射線計測技術に
おいて、中性子線を効率よく計測するためにＨｅ−３中
性子計数管の構造を改善した装置に関する技術分野であ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technical field of radiation measurement technology in which the structure of a He-3 neutron counter is improved in order to efficiently measure neutron rays.
【０００２】[0002]
【従来の技術】従来のＨｅ−３中性子計数管は、円筒形
の中心に陽極電極を、外壁を陰極とし、これに高純度、
高圧のＨｅ−３ガス注入した構造である。電極には、数
千ボルトの電圧を印加し、比例計数領域で利用する。2. Description of the Related Art A conventional He-3 neutron counter has an anode electrode at the center of a cylindrical shape and a cathode at an outer wall.
This is a structure in which high-pressure He-3 gas is injected. A voltage of several thousand volts is applied to the electrodes and used in the proportional counting region.
【０００３】Ｈｅ−３中性子計数管は、比例領域で使用
するため、ガス増幅に約１０６Ｖ／ｍの高電場が必要で
ある。中性子の計数効率を高めるため、検出容積を大き
くすると、電極間距離が離れることになる。このため、
ガス増幅に必要な高電場の確保には、高電圧を供給する
ことが必要となり、回路設計上問題となる。Since the He-3 neutron counter is used in the proportional region, a high electric field of about 10 6 V / m is required for gas amplification. If the detection volume is increased in order to increase the neutron counting efficiency, the distance between the electrodes will increase. For this reason,
In order to secure a high electric field required for gas amplification, it is necessary to supply a high voltage, which is a problem in circuit design.
【０００４】幾何学的計数効率を高めるため、平面に密
着する長方形とすると、計数管にかかる電場が不均一に
なる部分が生じ、計数効率を悪くすることになる。If a rectangular shape is used in order to increase the geometrical counting efficiency, a portion where the electric field applied to the counter tube becomes non-uniform occurs, and the counting efficiency is deteriorated.
【０００５】ガス増幅に必要な高電場を得るために、単
に複数の陽極電極を計数管内に設置すると、中性子の核
反応により生成した陽子が内部のＨｅ−３ガスをイオン
化し、このうち陽イオンが電極の中間付近に空間電荷層
として残留する。このため、計数効率を低下する原因と
なる。When a plurality of anode electrodes are simply placed in a counter tube to obtain a high electric field required for gas amplification, protons generated by a neutron nuclear reaction ionize the internal He-3 gas. Remains as a space charge layer near the center of the electrode. This causes a reduction in counting efficiency.
【０００６】[0006]
【発明が解決しようとする課題】本発明が解決しようと
する課題は、物質内部の水分量（含水素量）および欠陥
等を被測定物の外部から検知するため、散乱、あるいは
透過した中性子線を効率良く計測しうるＨｅ−３中性子
計数装置を作成することにある。The object of the present invention is to detect the water content (hydrogen content) and defects inside a substance from the outside of an object to be measured, so that a scattered or transmitted neutron beam is detected. Is to create a He-3 neutron counter capable of efficiently measuring neutrons.
【０００７】[0007]
【課題を解決するための手段】本発明は、被測定物内に
おける散乱、透過した中性子線を効率良く計測するた
め、計数管内に高純度のＨｅ−３ガスと添加物を注入
し、これに複数の陽極電極およびメッシュ状のグリット
電極を配置した高性能Ｈｅ−３中性子計数装置であるこ
とを特徴とするものである。According to the present invention, a high-purity He-3 gas and an additive are injected into a counter tube in order to efficiently measure scattered and transmitted neutron rays in an object to be measured. It is a high-performance He-3 neutron counter in which a plurality of anode electrodes and mesh-like grit electrodes are arranged.
【０００８】[0008]
【発明の実施の形態】上記のような構造のＨｅ−３中性
子計数管において、Ｈｅ−３ガスのイオン化により生成
されたイオンを効率良く電極に集めるためには、計数部
分のガス増幅に必要な高電場が均一にかかることが必要
となる。このためには、複数の陽極電極を設置し、陽極
電極間の中間付近にメッシュ状のグリッド電極を配置す
る。この作用は、Ｈｅ−３がイオン化されて生成した、
電子と陽イオンがそれぞれ陽極と陰極に移動する。この
際に、電子は易動度が高いので、容易に陰極に到達する
が、陽イオンは易動度が低いため、陽極間に滞留し、電
子の移動を妨げることになる。この現象を緩和するた
め、陽極と陽極の中間付近に陰極としてメッシュ状のグ
リッド電極を配置する。以下に具体的に記述する。DESCRIPTION OF THE PREFERRED EMBODIMENTS In a He-3 neutron counter having the above-mentioned structure, in order to efficiently collect ions generated by ionization of He-3 gas at an electrode, it is necessary to amplify gas in a counting portion. It is necessary to apply a high electric field uniformly. To this end, a plurality of anode electrodes are provided, and a mesh grid electrode is arranged near the middle between the anode electrodes. This action is produced by the ionization of He-3,
Electrons and cations move to the anode and cathode, respectively. At this time, the electrons easily reach the cathode because of their high mobility, but the cations stay between the anodes because of their low mobility and hinder the movement of the electrons. To alleviate this phenomenon, a mesh grid electrode is arranged as a cathode near the middle between the anodes. The details are described below.
【０００９】陽極電極は、均一な細線とし、できるだけ
高電場を得るため、４０μｍ以下のタングステン線ある
いいは白金線等を使用する。For the anode electrode, a tungsten wire or a platinum wire of 40 μm or less is used in order to form a uniform thin wire and obtain an electric field as high as possible.
【００１０】Ｈｅ−３中性子計数管は比例計数領域で使
用するため、ガス増幅に必要な最低の電場を超える電圧
を外部から供給する。このとき、陽極、陰極電極間にか
ける電圧は回路設計上できるだけ低くする必要がある。
このため、複数の陽極電極を配置し、電極間距離を短く
することにより高電場を確保する。Since the He-3 neutron counter is used in the proportional counting region, a voltage exceeding the minimum electric field required for gas amplification is externally supplied. At this time, the voltage applied between the anode and the cathode needs to be as low as possible in circuit design.
For this reason, a high electric field is secured by arranging a plurality of anode electrodes and shortening the distance between the electrodes.
【００１１】上記陽極電極において、長方形の形状を有
する計数管は、外側を陰極とし、内側の電極を陽極とし
たとき高電場が均一にかかりにくい。このため、中性子
線がＨｅ−３ガスと反応して生成したイオンの収集効率
が悪くなる。そこで、図１に示すようなＨｅ−３計数管
内に複数の陽極電極を設置し、生成イオンの収集効率を
高める構造とする。In the above-mentioned anode electrode, the counter tube having a rectangular shape is not easily applied with a high electric field uniformly when the outside is a cathode and the inside electrode is an anode. For this reason, the collection efficiency of ions generated by the reaction of the neutron beam with the He-3 gas deteriorates. Therefore, a plurality of anode electrodes are provided in a He-3 counter tube as shown in FIG. 1 to increase the collection efficiency of generated ions.
【００１２】上記陽極電極において、円筒形の形状を有
する計数管は、円筒形の中心と外側を陰極とし、図２に
示すように複数の陽極電極を配置した構造とする。In the above anode electrode, the counter tube having a cylindrical shape has a structure in which the center and the outside of the cylindrical shape are used as cathodes and a plurality of anode electrodes are arranged as shown in FIG.
【００１３】Ｈｅ−３計数管内に複数の陽極電極を配置
することにより、電極の中間付近に空間電荷層ができ、
生成イオンの移動を阻害することになる。このため、図
１，図２に示すように陽極電極の中間付近にメッシュ状
のグリッド電極を置き、陽イオンを除去することにより
電子の収集効率を高める構造とする。By arranging a plurality of anode electrodes in the He-3 counter tube, a space charge layer is formed near the center of the electrodes,
This will hinder the transfer of generated ions. For this reason, as shown in FIGS. 1 and 2, a mesh-shaped grid electrode is placed near the center of the anode electrode, and a structure is provided in which cations are removed to increase electron collection efficiency.
【００１４】[0014]
【発明の効果】本発明は、中性子線により物質内部の水
分量（含水素量）および欠陥等を被測定物の外部から検
知するため、Ｈｅ−３計数管の形状を被測定物に密着す
ることのできる形状とし、計数管内で中性子線により生
成された電荷の収集効率を高めるため複数の陽極電極と
電極間にグリッド電極を配置した構造とする。このこと
により、物質中で散乱、透過した中性子線を効率良く計
測し、被測定物中の水分量および欠陥等を高精度で検知
することができる。According to the present invention, the shape of the He-3 counter tube is brought into close contact with the object to be measured, since the water content (hydrogen content), defects, and the like inside the substance are detected from the outside of the object by the neutron beam. And a grid electrode arranged between a plurality of anode electrodes and between the electrodes in order to increase the collection efficiency of the charge generated by the neutron beam in the counter tube. This makes it possible to efficiently measure the neutron beam scattered and transmitted through the substance, and to detect the moisture content, defects, and the like in the measured object with high accuracy.
【図１】長方形高性能Ｈｅ−３中性子計数装置の立体図FIG. 1 is a three-dimensional view of a rectangular high-performance He-3 neutron counter.
【図２】円筒形高性能Ｈｅ−３中性子計数装置の立体図FIG. 2 is a three-dimensional view of a cylindrical high-performance He-3 neutron counter.
【符号の説明】 グリッド電極 陽極 陰極 絶縁物 Ｈｅ−３ガス封入 高電圧コネクター[Description of Symbols] Grid electrode Anode Cathode Insulator He-3 gas filled High voltage connector
Claims (2)
線とＨｅ−３ガスが核反応をし、陽子線を発生する。こ
の陽子線がＨｅ−３ガスをイオン化するが、高電圧をか
けて生成イオンを収集するとき、計数管の形状および検
出容積により高電圧が均一にかかりにくい。そこで、陽
極電極を複数配置することにより、比例計数領域の検出
器特性（プラトー特性、エネルギー分解能、検出効率）
を改善したＨｅ−３中性子計数管とする。In a He-3 neutron counter, a neutron beam and a He-3 gas undergo a nuclear reaction to generate a proton beam. The proton beam ionizes the He-3 gas, but when a high voltage is applied to collect generated ions, it is difficult to apply a high voltage uniformly due to the shape and detection volume of the counter tube. Therefore, by arranging a plurality of anode electrodes, detector characteristics (plateau characteristics, energy resolution, detection efficiency) in the proportional counting area
And a He-3 neutron counter with improved characteristics.
数管において、計数管内に生成した電子および陽イオン
のうち、陽イオンは電極の中間付近に空間電荷層を形成
し、生成電子の電極への移動を阻害する。この陽イオン
による空間電荷層を排除するため、陽極電極の中間付近
にメッシュ状のグリッド電極を陰極として配置したＨｅ
−３中性子計数管とする。2. In a He-3 neutron counter in which a plurality of electrodes are arranged, of the electrons and cations generated in the counter, the cations form a space charge layer near the middle of the electrodes, and the generated electrons Inhibit migration to In order to eliminate the space charge layer due to the cations, a He grid in which a mesh grid electrode is arranged as a cathode near the center of the anode electrode.
-3 Neutron counter.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000237735A JP2002014171A (en) | 2000-06-30 | 2000-06-30 | HIGH-PERFORMANCE He-3 COUNTER FOR NEUTRON |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000237735A JP2002014171A (en) | 2000-06-30 | 2000-06-30 | HIGH-PERFORMANCE He-3 COUNTER FOR NEUTRON |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2002014171A true JP2002014171A (en) | 2002-01-18 |
Family
ID=18729541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000237735A Pending JP2002014171A (en) | 2000-06-30 | 2000-06-30 | HIGH-PERFORMANCE He-3 COUNTER FOR NEUTRON |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2002014171A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008180647A (en) * | 2007-01-25 | 2008-08-07 | Kobe Univ | Gas radiation detector by pixel-type electrode using micro mesh |
| WO2013132554A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation detection device |
| WO2013132556A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation detection device |
| WO2013132553A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation-detecting device |
| WO2013132555A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation detection device |
-
2000
- 2000-06-30 JP JP2000237735A patent/JP2002014171A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008180647A (en) * | 2007-01-25 | 2008-08-07 | Kobe Univ | Gas radiation detector by pixel-type electrode using micro mesh |
| WO2013132554A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation detection device |
| WO2013132556A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation detection device |
| WO2013132553A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation-detecting device |
| WO2013132555A1 (en) * | 2012-03-07 | 2013-09-12 | パナソニック株式会社 | Radiation detection device |
| JP5559934B2 (en) * | 2012-03-07 | 2014-07-23 | パナソニック株式会社 | Radiation detector |
| US8835863B2 (en) | 2012-03-07 | 2014-09-16 | Panasonic Corporation | Radiation detector |
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