JPS6241377B2 - - Google Patents
Info
- Publication number
- JPS6241377B2 JPS6241377B2 JP55004230A JP423080A JPS6241377B2 JP S6241377 B2 JPS6241377 B2 JP S6241377B2 JP 55004230 A JP55004230 A JP 55004230A JP 423080 A JP423080 A JP 423080A JP S6241377 B2 JPS6241377 B2 JP S6241377B2
- Authority
- JP
- Japan
- Prior art keywords
- detection signal
- detection
- gate
- amplifier
- dynodes
- 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.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
- G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
- G01T1/16—Measuring radiation intensity
- G01T1/20—Measuring radiation intensity with scintillation detectors
- G01T1/208—Circuits specially adapted for scintillation detectors, e.g. for the photo-multiplier section
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Physics & Mathematics (AREA)
- High Energy & Nuclear Physics (AREA)
- Molecular Biology (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Measurement Of Radiation (AREA)
- Electron Tubes For Measurement (AREA)
- Analysing Materials By The Use Of Radiation (AREA)
Description
【発明の詳細な説明】
本発明は質量分析装置、イオンマイクロアナラ
イザ等の検出系の様に２次電子増倍管を備えた検
出装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detection device equipped with a secondary electron multiplier, such as a detection system such as a mass spectrometer or an ion microanalyzer.
従来２次電子増倍管を備えた検出装置は例えば
第１図に示す様な構成を有している。同図におい
てD1〜Ｄoはダイノードであり、各ダイノードに
は高圧電源１からの負電圧を抵抗２によつて分圧
して供給している。３は電子コレクタ、４は該コ
レクタ３に流入する電流を電圧信号として取り出
す電流検出増巾器である。 A conventional detection device equipped with a secondary electron multiplier has a configuration as shown in FIG. 1, for example. In the figure, D 1 to D o are dynodes, and a negative voltage from a high voltage power supply 1 is divided by a resistor 2 and supplied to each dynode. 3 is an electronic collector, and 4 is a current detection amplifier that extracts the current flowing into the collector 3 as a voltage signal.
この様な従来装置では得られる検出信号ａのダ
イナミツクレンジは増巾器４のノイズレベルに依
存するので限界があり、その限界を超えてダイナ
ミツクレンジを拡大するために(1)高圧電源１の出
力電圧を切換えて増倍管の利得を変えるか、又は
(2)増巾器４の帰還抵抗を切換えて利得を変えるこ
とが行なわれていた。 In such a conventional device, the dynamic range of the detection signal a obtained is limited because it depends on the noise level of the amplifier 4. In order to expand the dynamic range beyond that limit, (1) the high voltage power supply 1 Change the gain of the multiplier tube by switching the output voltage of the
(2) The gain was changed by switching the feedback resistor of the amplifier 4.
ところが(1)、(2)とも切換えてから安定状態にな
るまでの切換時間が数10ミリsec以上になるた
め、検出信号が１ミリsec以下の早い変動を含む
質量分析装置の場合は測定中の切換はできず、測
定する前にオペレータが予め切換操作を行う必要
があり面倒であつた。 However, in both (1) and (2), the switching time from switching to stabilization is several tens of milliseconds or more, so in the case of a mass spectrometer where the detection signal includes rapid fluctuations of less than 1 millisecond, it may be difficult to obtain a stable state during measurement. It was not possible to switch between the two, and the operator had to perform a switching operation before making a measurement, which was troublesome.
本発明はこの様な従来の問題点に鑑みてなされ
たものであり、２次電子増倍管の１つ又はそれ以
上の中間段ダイノードに流入する個々の電流を検
出する電流検出増巾器を付加し、各々の増巾器か
らの検出信号及び電子コレクタから得られる本来
の検出信号のうち飽和しないで最もレベルの大き
いものを選択的に取出すための選択手段を設ける
ことによりダイナミツクレンジの切換を瞬時に行
うことのできる検出装置を提供することを目的と
するものである。以下図面を用いて本発明を詳述
する。 The present invention has been made in view of these conventional problems, and provides a current detection amplifier for detecting individual currents flowing into one or more intermediate stage dynodes of a secondary electron multiplier. In addition, dynamic range switching is achieved by providing a selection means for selectively extracting the highest level signal without saturation among the detection signals from each amplifier and the original detection signal obtained from the electronic collector. The object of the present invention is to provide a detection device that can instantaneously perform the following steps. The present invention will be explained in detail below using the drawings.
第２図は本発明の一実施例の構成を示す図であ
り、第１図に示された従来例に加えて所定の中間
段ダイノードＤaに流入する電子流を検出するた
めの電流検出増巾器５が設けられている。該増巾
器５から得られた検出信号ｂは直流高電圧に重畳
しているため、光半導体素子等を用いて入出力間
を直流的に絶縁した絶縁型直流増巾器６を介して
取り出される。７は該検出信号ｂ又は電流検出増
巾器４からの検出信号ａのいずれか一方を取り出
すためのFETゲートであり、該FETゲートは選
択回路８によつて切換えられる。 FIG. 2 is a diagram showing the configuration of an embodiment of the present invention, in which, in addition to the conventional example shown in FIG. A drawer 5 is provided. Since the detection signal b obtained from the amplifier 5 is superimposed on a high DC voltage, it is taken out via an isolated DC amplifier 6 in which the input and output are DC-insulated using an optical semiconductor element or the like. It can be done. Reference numeral 7 denotes a FET gate for taking out either the detection signal b or the detection signal a from the current detection amplifier 4, and the FET gate is switched by the selection circuit 8.
この様な構成において検出信号ｂは中間段ダイ
ノードＤaから取出されているため、検出信号ａ
よりもレベルが小さい。説明を簡単にするため、
その比が例えば１／10になるようにダイノードＤ
aが選択されており、検出信号ａ，ｂのダイナミ
ツクレンジが0V〜10Vであつたとする。ここで選
択回路８は基準レベルとして1Vと10Vが設定され
ており、ゲート７の出力が10Vになると検出信号
ｂを取り出し、ゲート７の出力が1Vを下回ると
検出信号ａを取り出すようにFETを制御する。 In such a configuration, since the detection signal b is taken out from the intermediate stage dynode D a , the detection signal a
The level is smaller than. To simplify the explanation,
Dynode D so that the ratio is, for example, 1/10.
Suppose that a is selected and the dynamic range of the detection signals a and b is 0V to 10V. Here, the selection circuit 8 is set to 1V and 10V as reference levels, and the FET is configured so that when the output of the gate 7 reaches 10V, the detection signal b is taken out, and when the output of the gate 7 falls below 1V, the detection signal a is taken out. Control.
そのため、検出信号ａが選択されていて、その
検出信号ａが増大して10Vに達して飽和してしま
つた場合、選択回路８はゲート７の出力が10Vに
達したことを検出して瞬時にゲート７を切換える
ため、ゲート７からは飽和していない検出信号ｂ
が得られる。その後取り出された検出信号ｂが減
少し1Vを下回つた場合、選択回路８はゲート７
の出力が1Vを下回つたことを検出して瞬時にゲ
ート７を切換えるため、ゲートからはレベルが大
きい検出信号ａが得られる。従つて第１図の例に
比べダイナミツクレンジが10倍に拡大されたこと
になる。しかも検出信号ａ，ｂは常に得られてお
り、それをゲートで切換えるので切換時間は極め
て短かく、１回の測定中に検出信号レベルに応じ
た切換を多数繰返しても影響がない。 Therefore, if the detection signal a is selected and the detection signal a increases and reaches 10V and becomes saturated, the selection circuit 8 detects that the output of the gate 7 reaches 10V and instantly Since gate 7 is switched, an unsaturated detection signal b is output from gate 7.
is obtained. When the detection signal b extracted after that decreases and falls below 1V, the selection circuit 8 selects the gate 7.
Since the gate 7 is switched instantaneously upon detecting that the output has fallen below 1V, a detection signal a with a high level is obtained from the gate. Therefore, the dynamic range is expanded 10 times compared to the example shown in FIG. Moreover, since the detection signals a and b are always obtained and are switched by the gate, the switching time is extremely short, and there is no effect even if the switching is repeated many times according to the detection signal level during one measurement.
尚上述した実施例では１つの中間段ダイノード
Ｄaにのみ電流検出増巾器を設けたが、それに限
らず２つあるいはそれ以上の中間段ダイノードに
電流検出増巾器を設け、各々の増巾器から得られ
る検出信号のうち飽和しないで最もレベルの大き
いものを選択するようにすれば良い。 In the embodiment described above, only one intermediate stage dynode D a is provided with a current detection amplifier, but the current detection amplifier is not limited to this, but two or more intermediate stage dynodes are provided with current detection amplifiers, and each amplifier Of the detection signals obtained from the detector, the one with the highest level without saturation may be selected.
又上述した実施例では選択回路８はゲート７の
出力レベルを判定するようにしたが、これに限ら
ずゲート７の前の段階で検出信号レベルを判定す
るようにしてもよい。ただしその場合は各検出信
号についてレベルを判定しなければならない。そ
の点第２図の実施例ではゲート７の出力レベルの
みを判定するだけでよい。 Further, in the above-described embodiment, the selection circuit 8 determines the output level of the gate 7, but the present invention is not limited to this, and the detection signal level may be determined at a stage before the gate 7. However, in that case, the level must be determined for each detection signal. In this respect, in the embodiment shown in FIG. 2, it is only necessary to determine the output level of the gate 7.
更に上述した実施例におけるゲート７及び選択
回路からなる選択手段はコンピユータに置きかえ
ることが可能である。 Furthermore, the selection means consisting of the gate 7 and the selection circuit in the above-described embodiment can be replaced with a computer.
第１図は従来例の構成図、第２図は本発明の一
実施例の構成図である。
D1〜Ｄo：ダイノード、４，５：電流検出増巾
器、６：絶縁型直流増巾器、７：FETゲート、
８：選択回路。
FIG. 1 is a block diagram of a conventional example, and FIG. 2 is a block diagram of an embodiment of the present invention. D 1 to D o : dynode, 4, 5: current detection amplifier, 6: isolated DC amplifier, 7: FET gate,
8: Selection circuit.
Claims (1)
増倍された２次電子流を集める電子コレクタとを
有する２次電子増倍管と、上記ダイノードのうち
１つ又はそれ以上の個々のダイノードに流入する
電流を検出する手段と、該検出手段から得られる
１つ又はそれ以上の検出信号と前記電子コレクタ
から得られる検出信号を選択的に取り出す手段と
からなることを特徴とする２次電子増倍管を備え
た検出装置。1. A secondary electron multiplier having a plurality of stages of dynodes and an electron collector that collects the secondary electron flow multiplied by the dynodes, and flowing into one or more individual dynodes of the dynodes. A secondary electron multiplier tube comprising means for detecting current, and means for selectively extracting one or more detection signals obtained from the detection means and the detection signal obtained from the electron collector. A detection device equipped with
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP423080A JPS56101581A (en) | 1980-01-18 | 1980-01-18 | Detection device provided with secondary electron multiplier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP423080A JPS56101581A (en) | 1980-01-18 | 1980-01-18 | Detection device provided with secondary electron multiplier |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56101581A JPS56101581A (en) | 1981-08-14 |
| JPS6241377B2 true JPS6241377B2 (en) | 1987-09-02 |
Family
ID=11578762
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP423080A Granted JPS56101581A (en) | 1980-01-18 | 1980-01-18 | Detection device provided with secondary electron multiplier |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56101581A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60187450U (en) * | 1984-05-22 | 1985-12-12 | 日本電子株式会社 | Secondary electron detection device for scanning electron microscope |
| US4631410A (en) * | 1984-10-03 | 1986-12-23 | Wisconsin Alumni Research Foundation | Method and apparatus for measurement of radioactivity over an extended range |
| JP2014119282A (en) * | 2012-12-13 | 2014-06-30 | Fuji Electric Co Ltd | Linearity-compensating bleeder circuit and radiation detector |
| JP6417139B2 (en) * | 2014-07-18 | 2018-10-31 | 浜松ホトニクス株式会社 | Output circuit for electron multiplier |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5343068U (en) * | 1976-09-18 | 1978-04-13 |
-
1980
- 1980-01-18 JP JP423080A patent/JPS56101581A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56101581A (en) | 1981-08-14 |
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