JP2006113010A - Discriminational measuring method of prompt and disintegration gamma rays by time list measurement - Google Patents

Discriminational measuring method of prompt and disintegration gamma rays by time list measurement Download PDF

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JP2006113010A
JP2006113010A JP2004302928A JP2004302928A JP2006113010A JP 2006113010 A JP2006113010 A JP 2006113010A JP 2004302928 A JP2004302928 A JP 2004302928A JP 2004302928 A JP2004302928 A JP 2004302928A JP 2006113010 A JP2006113010 A JP 2006113010A
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gamma ray
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Hideaki Matsue
秀明 松江
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Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for enhancing the probability of an analysis by clearly discriminating prompt gamma rays and disintegration gamma rays to measure them. <P>SOLUTION: A pulse neutron beam is utilized to set a neutron pulse generating signal as a start signal, and the time data from the start signal and a gamma ray detecting phase are preserved in a list made and analyzed to measure the spectra of time-resolved prompt and disintegration gamma rays. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

この発明は、即発ガンマ線及び壊変ガンマ線スペクトルを分別して測定する技術に関する。   The present invention relates to a technique for separately measuring prompt gamma rays and decay gamma rays.

中性子ビームを測定試料に照射すると直ちに測定試料から即発ガンマ線が放射される。この即発ガンマ線を測定し、ガンマ線エネルギーから元素の同定、ガンマ線強度から元素量の定量を行う分析法が即発ガンマ線分析法である。この際、中性子捕獲反応により生成する短半減期の放射性核種からの壊変ガンマ線も同時に測定される。   As soon as the measurement sample is irradiated with the neutron beam, prompt gamma rays are emitted from the measurement sample. Prompt gamma ray analysis is an analysis method that measures prompt gamma rays, identifies elements from gamma ray energy, and quantifies element amounts from gamma ray intensity. At this time, decay gamma rays from short-lived radionuclides generated by the neutron capture reaction are also measured.

しかしながら、以上の技術によれば、即発ガンマ線と壊変ガンマ線は同一ガンマ線スペクトル中に記録され、お互いを明白に分離することは困難であった。そのため、１）壊変ガンマ線ピークが分析対象の即発ガンマ線ピークの妨害ピークとなる、２）壊変ガンマ線が即発ガンマ線スペクトルのバックグラウンド増加の一因となる、３）壊変ガンマ線を分析に用いることは即発ガンマ線のバックグラウンドにより困難である、などの問題があった。   However, according to the above technique, prompt gamma rays and decay gamma rays are recorded in the same gamma ray spectrum, and it is difficult to clearly separate them from each other. Therefore, 1) the decay gamma ray peak becomes an interference peak of the prompt gamma ray peak to be analyzed, 2) the decay gamma ray contributes to the background increase of the prompt gamma ray spectrum, and 3) the use of the decay gamma ray for analysis is a prompt gamma ray. There were problems such as being difficult due to background.

さらに、パルス中性子を利用する即発ガンマ線測定では、中性子の有無によってパルス周期内のガンマ線強度の変化が生じる。その変化に対応したガンマ線検出系の不感時間補正の必要性の有無の確認及び補正法の確立が課題となる。   Furthermore, in prompt gamma ray measurement using pulsed neutrons, the gamma ray intensity changes within the pulse period depending on the presence or absence of neutrons. Confirmation of the necessity of dead time correction of the gamma ray detection system corresponding to the change and establishment of a correction method are problems.

本発明は、即発ガンマ線と壊変ガンマ線を明白に分別して測定することで分析の確度を向上させる技術を提供することを課題とする。   An object of the present invention is to provide a technique for improving the accuracy of analysis by clearly distinguishing and measuring prompt gamma rays and decay gamma rays.

以上の課題を解決するために、第一発明は、中性子ビームとして、パルス中性子ビームを利用し、中性子パルス発生信号をスタート信号として、スタート信号からの経過時間情報とガンマ線検出事象情報をリストモードで記録し、ガンマ線スペクトルに経過時間情報を加え、時間分解即発ガンマ線及び壊変ガンマ線スペクトルの測定を行うことを特徴とする測定技術である。   In order to solve the above problems, the first invention uses a pulsed neutron beam as a neutron beam, a neutron pulse generation signal as a start signal, and elapsed time information from the start signal and gamma ray detection event information in a list mode. It is a measurement technique characterized by recording, adding elapsed time information to a gamma ray spectrum, and measuring time-resolved prompt gamma rays and decay gamma ray spectra.

第二発明は中性子照射時の即発ガンマ線スペクトルから中性子未照射時の壊変ガンマ線スペクトルを差し引くことで、即発ガンマ線スペクトルから壊変ガンマ線スペクトル成分を差し引くものであり、即発ガンマ線スペクトルのバックグラウンド抑制に効果的な測定技術である。   The second invention subtracts the decay gamma ray spectrum when no neutrons are irradiated from the prompt gamma ray spectrum at the time of neutron irradiation, and subtracts the decay gamma ray spectrum component from the prompt gamma ray spectrum, which is effective for suppressing the background of the prompt gamma ray spectrum. Measurement technology.

第三発明は、パルス中性子ビームを利用した即発ガンマ線測定では中性子ビームの在る無しに対応して測定試料からのガンマ線強度の大きな変化が予想される。従って、中性子の在る無しに伴うガンマ線検出器の不感時間の補正が必要となる。この不感時間の補正のために、中性子照射時に生成する中性子パルスビーム周期に対して長半減期の放射性核種からの壊変ガンマ線強度を用いて、中性子ビームの在る無しに対応した測定系全体の不感時間の補正を簡便に行うものである。
上記不感時間とは、測定システムがパルスの処理に利用できない時間のことであり、一般的に高計数率の測定では不感時間が多くなり計数率が減少する。本発明におけるように、測定中に大きな計数率の変化が予想される系では、不感時間の評価が重要になる。
即ち、本発明は、中性子パルスビームを測定試料に照射し、中性子照射時のみ即発ガンマ線を放射させ、中性子照射による生成核種の半減期に応じて壊変ガンマ線を放射させ、その即発ガンマ線と壊変ガンマ線をガンマ線検出器で検出し、検出ガンマ線をガンマ線測定回路でガンマ線信号に整形してリストモード対応多重波高分析器に入力し、ガンマ線発生毎にそのエネルギー情報と時間情報を逐次リストファイルに保存し、保存されたエネルギー情報と時間情報を有するリストデータからガンマ線エネルギーと経過時間に対する計数値をプロットして時間分解即発ガンマ線スペクトル及び壊変ガンマ線スペクトルを得、これらのスペクトルを解析することにより、即発ガンマ線及び壊変ガンマ線を分別して測定する方法である。
又、本発明は、上記即発ガンマ線及び壊変ガンマ線を分別して測定する方法において、中性子照射時の即発ガンマ線スペクトル成分から中性子未照射時の壊変ガンマ線スペクトル成分を差し引くことにより、即発ガンマ線スペクトルに対する壊変ガンマ線スペクトルによる影響を抑制して即発ガンマ線と壊変ガンマ線を明白に分別して測定することで分析の確度を向上させるものである。
更に又、本発明は、上記即発ガンマ線及び壊変ガンマ線を分別して測定する方法において、生成放射性核種の半減期が、中性子照射周期に対して長い場合、即ち、測定系の中性子パルスビームの照射周期を大きく越える場合には、その生成放射性核種からの壊変ガンマ線ピークが経過時間に関係なくほぼ一定の強度を保つので、中性子パルスビーム周期に対して長半減期の生成放射性核種からの壊変ガンマ線ピーク強度を用いて、中性子ビームの在る無しにかかわらず測定系全体の即発ガンマ線の補正を行うことができるものである。これは、生成放射性核種の壊変による減衰を無視できるほど早く次の中性子パルスが来ると壊変を無視できることを意味している。 In the third invention, in the prompt gamma ray measurement using a pulsed neutron beam, a large change in the gamma ray intensity from the measurement sample is expected corresponding to the presence or absence of the neutron beam. Therefore, it is necessary to correct the dead time of the gamma ray detector due to the presence or absence of neutrons. In order to correct this dead time, the entire measurement system was insensitive to the presence or absence of the neutron beam using decay gamma ray intensity from radionuclides with a long half-life with respect to the period of the neutron pulse beam generated during neutron irradiation. Time correction is easily performed.
The dead time is a time that the measurement system cannot use for processing the pulse. Generally, in the measurement with a high count rate, the dead time increases and the count rate decreases. As in the present invention, in a system in which a large change in the count rate is expected during measurement, evaluation of dead time becomes important.
That is, the present invention irradiates a measurement sample with a neutron pulse beam, emits prompt gamma rays only at the time of neutron irradiation, emits decay gamma rays according to the half-life of the nuclides produced by neutron irradiation, and emits the prompt gamma rays and decay gamma rays. Detected by a gamma ray detector, shaped the detected gamma ray into a gamma ray signal by a gamma ray measurement circuit, input it to the list mode compatible multi-wave height analyzer, and saves the energy information and time information in a list file each time a gamma ray is generated. Time-resolved prompt gamma-ray spectra and decayed gamma-ray spectra by plotting gamma-ray energy and counts against elapsed time from the list data having the energy information and time information obtained, and analyzing these spectra, prompt gamma rays and decayed gamma rays This is a method of measuring by separating.
Further, the present invention relates to the method for separately measuring prompt gamma rays and decay gamma rays, and subtracting the decay gamma ray spectrum component when no neutrons are irradiated from the prompt gamma ray spectrum component when neutrons are irradiated, thereby obtaining a decay gamma ray spectrum with respect to the prompt gamma ray spectrum. The accuracy of the analysis is improved by suppressing the influence of, and promptly separating and measuring prompt gamma rays and destructive gamma rays.
Furthermore, the present invention provides a method for separately measuring prompt gamma rays and decayed gamma rays in the case where the half-life of the generated radionuclide is longer than the neutron irradiation period, that is, the irradiation period of the neutron pulse beam of the measurement system. If it greatly exceeds, the decay gamma-ray peak from the generated radionuclide maintains an almost constant intensity regardless of the elapsed time, so the decay gamma-ray peak intensity from the produced radionuclide having a long half-life with respect to the neutron pulse beam period is reduced. It is possible to correct prompt gamma rays in the entire measurement system regardless of the presence or absence of a neutron beam. This means that the decay can be ignored when the next neutron pulse comes so early that the decay due to decay of the produced radionuclide is negligible.

第一発明によれば、パルス中性子ビームとその中性子パルス・スタート信号からの経過時間情報を利用することで、時間軸に対してガンマ線スペクトルが得られる。得られた時間分解ガンマ線スペクトル中のガンマ線ピーク強度の時間依存性から明白に即発ガンマ線と壊変ガンマ線の識別が容易に可能であり、さらに任意の時間領域で時間軸に対してそれぞれのガンマ線スペクトルを積算することで特定の時間領域におけるガンマ線スペクトルを再構成することができる。従って、時間領域を指定すれば即発ガンマ線及び壊変ガンマ線スペクトルを識別して取得可能となる。   According to the first invention, a gamma ray spectrum can be obtained with respect to the time axis by using the pulsed neutron beam and the elapsed time information from the neutron pulse start signal. From the time dependence of the gamma-ray peak intensity in the obtained time-resolved gamma-ray spectrum, it is clear that prompt gamma rays and decayed gamma rays can be easily distinguished, and each gamma-ray spectrum is integrated with respect to the time axis in any time domain. By doing so, a gamma ray spectrum in a specific time domain can be reconstructed. Therefore, if a time domain is designated, prompt gamma rays and decay gamma ray spectra can be identified and acquired.

第二発明によれば、第一発明により取得した即発ガンマ線スペクトルから壊変ガンマ線スペクトルを差分することによりパルス中性子周期に対して長半減の壊変核種からのガンマ線成分を抑制し、即発ガンマ線スペクトルのバックグランド抑制及びピーク計数―バックグランド計数比の向上を行うことができる。
ピーク計数―バックグランド計数比とは、本発明では、ピーク計数率が減少することなくピークの底辺にあるバックグランド係数が減少することを指し、このことにより、１）バックグランドに埋もれて見えなかったピークが認識できるようになる、２）ピークの統計誤差が小さくなる、などの利点が生じる。 According to the second invention, the gamma ray component from the decayed nuclide that is halved to the pulse neutron period is suppressed by subtracting the decayed gamma ray spectrum from the prompt gamma ray spectrum acquired by the first invention, and the background of the prompt gamma ray spectrum is obtained. Suppression and peak count-background count ratio can be improved.
In the present invention, the peak count-background count ratio means that the background coefficient at the bottom of the peak decreases without decreasing the peak count rate. This makes it possible to recognize the peak and 2) the statistical error of the peak is reduced.

第三発明によれば、中性子パルス周期に対して長半減期核種の壊変ガンマ線強度は時間依存性がなく、該当壊変ガンマ線強度の変化は不感時間の影響によるものである。従って、不感時間補正の必要性の有無は、該当壊変ガンマ線強度の変化を確認することで確認でき、補正が必要となる場合でも該当壊変ガンマ線強度変化から容易に補正が可能となる。   According to the third invention, the decay gamma ray intensity of the long half-life nuclide is not time-dependent with respect to the neutron pulse period, and the change in the decay gamma ray intensity is due to the dead time. Therefore, whether or not the dead time needs to be corrected can be confirmed by confirming the change in the corresponding decay gamma ray intensity, and even when correction is necessary, it can be easily corrected from the change in the corresponding decay gamma ray intensity.

この発明の一実施形態を、図１に示す。中性子ビーム１は、中性子ディスクチョッパー２によりパルス化され中性子パルスビームとなる。中性子パルスビームは測定試料３に照射され、中性子照射時のみ即発ガンマ線４が放射され、壊変ガンマ線５はその半減期に応じて照射中にその強度が増加し、未照射時に減衰しながら放射される。即発ガンマ線４と壊変ガンマ線５はガンマ線検出器６で検出され、ガンマ線測定回路７でガンマ線信号８に整形されリストモード対応多重波高分析器９に入力される。
一方、中性子をチョップする中性子ディスクチョッパー２の中性子窓１０の開閉情報はスタート信号１１としてリストモード対応多重波高分析器９に入力される。リストモード対応多重波高分析器９は、ガンマ線信号を受け取ると中性子窓からの経過時間とエネルギーをハードディスク等にリストファイル１２として逐次保存していく。保存された時間情報とエネルギー情報を有するリストデータからガンマ線エネルギーと経過時間に対し計数値をプロットし時間分解即発及び壊変ガンマ線スペクトル１３が得られる。時間分解即発及び壊変ガンマ線スペクトル１３中で、即発ガンマ線ピーク１４は中性子ビームが測定試料に到着後直ちに立上り、ビームが無くなると直ちに立下り台形型のピーク形状をしている。壊変ガンマ線ピーク１５は、生成核種の半減期が中牲子照射時間に対して短いと中性予照射中に半減期に伴って強度が増加し、中性子未照射時に減衰するようなピーク形状をとり、半減期が中性子照射時間に対して長いと、測定系の不感時間の影響が無視できる場合には経過時間に関係なく一定の強度を保つ。 One embodiment of the present invention is shown in FIG. The neutron beam 1 is pulsed by a neutron disk chopper 2 to become a neutron pulse beam. The measurement sample 3 is irradiated with the neutron pulse beam, and prompt gamma rays 4 are emitted only at the time of neutron irradiation, and decay gamma rays 5 increase in intensity during irradiation according to their half-life and are emitted while decaying when not irradiated. . The prompt gamma ray 4 and the decayed gamma ray 5 are detected by a gamma ray detector 6, shaped into a gamma ray signal 8 by a gamma ray measurement circuit 7, and input to a list mode compatible multi-wave height analyzer 9.
On the other hand, the opening / closing information of the neutron window 10 of the neutron disk chopper 2 for chopping neutrons is input as a start signal 11 to the list mode compatible multi-wave height analyzer 9. When receiving the gamma ray signal, the list mode compatible multi-wave height analyzer 9 sequentially stores the elapsed time and energy from the neutron window as a list file 12 on a hard disk or the like. A count value is plotted with respect to gamma ray energy and elapsed time from the stored list data having time information and energy information, and a time-resolved prompt and decayed gamma ray spectrum 13 is obtained. In the time-resolved prompt and decay gamma-ray spectrum 13, the prompt gamma-ray peak 14 rises immediately after the neutron beam arrives at the measurement sample, and has a falling trapezoidal peak shape as soon as the beam disappears. The decay gamma-ray peak 15 takes a peak shape in which the intensity increases with the half-life during neutral pre-irradiation when the half-life of the produced nuclide is shorter than the neutron irradiation time, and decays when the neutron is not irradiated. When the half-life is long with respect to the neutron irradiation time, a constant intensity is maintained regardless of the elapsed time when the influence of the dead time of the measurement system can be ignored.

（実施形態の効果）
この実施形態によれば、スタート信号１１から時間情報とガンマ線検出事象をリストファイルに保存し、時間分解即発及び壊変ガンマ線スペクトル１３を取得することで即発ガンマ線と壊変ガンマ線を明白に分別して測定可能となる。時間分解即発及び壊変ガンマ線スペクトル１３データの任意の時間領域のスペクトルを時間軸で積算することで、特定の時間領域のガンマ線スペクトルを得ることができる。 (Effect of embodiment)
According to this embodiment, the time information and the gamma ray detection event are stored in the list file from the start signal 11 and the time-resolved prompt and decay gamma ray spectrum 13 is acquired, so that the prompt gamma ray and the decay gamma ray can be clearly separated and measured. Become. By integrating the time domain spectrum of the time-resolved prompt and decay gamma ray spectrum 13 data on the time axis, a gamma ray spectrum in a specific time domain can be obtained.

（他の実施形態）
図１の実施形態では、定常的な中性子ビームを中性子ディスクチョッパーによりパルス化しているが、他の実施形態では、中牲子パルスビームのスタート信号を利用すれば、加速器中性子源の様に元々中性子パルスビームを発生するものでも良い。 (Other embodiments)
In the embodiment of FIG. 1, a stationary neutron beam is pulsed by a neutron disk chopper. In other embodiments, if a start signal of a neutron pulse beam is used, the neutron beam is originally neutron like an accelerator neutron source. It may be one that generates a pulse beam.

時間分解即発及び壊変ガンマ線スペクトルの測定
Ｎａ2ＣＯ3 ０．３グラムを測定試料として時間分解即発及び壊変ガンマ線スペクトルを測定した。試料中のＮａは中性子捕獲反応の際に９２ｋｅＶをはじめ複数の即発ガンマ線を放射し、また２０ミリ秒という極短半減期を有する放射性同位元素24mＮａを生成する。24mＮａは４７２ｋｅＶの壊変ガンマ線を放射する。測定は原研東海研究所ＪＲＲ−３研究用原子炉の即発ガンマ線分析装置内に中牲子ディスクチョッパーを設置し、図１に示した測定スキームで行った。測定結果を図２に示す。図２における測定条件を以下に示す。測定時間３０００ｓｅｃ、時間分解能１ｍｓｅｃ、中性子パルス幅９４ｍｓｅｃ、パルス間隔；１８８ｍｓｅｃである。Ｎａの９２ｋｅＶ即発γ線は中性子パルス照射後直ちに立ち上がり、照射終了後に立ち下がっているのに対し、極短寿命核種である24mＮａ（半滅期２０ｍｓｅｃ）の４７２ｋｅＶ壊変γ線では照射中にγ線強度の成長曲線が見られ、照射終了後放射壊変に伴ってγ線強度が減衰する様子が認められる。このように本発明により即発ガンマ線と壊変ガンマ線を明確に分別して測定可能となった。 Measurement of time-resolved prompt and decay gamma-ray spectra Time-resolved prompt and decay gamma-ray spectra were measured using 0.3 g of Na 2 CO 3 as a measurement sample. Na in the sample emits a plurality of prompt gamma rays including 92 keV in the neutron capture reaction, and also generates a radioisotope 24m Na having an extremely short half-life of 20 milliseconds. 24 m Na emits 472 keV decay gamma rays. The measurement was carried out by the measurement scheme shown in FIG. 1 by installing a neutral disk chopper in the prompt gamma ray analyzer of the JAERI Tokai Research Laboratory JRR-3 research reactor. The measurement results are shown in FIG. The measurement conditions in FIG. 2 are shown below. The measurement time is 3000 sec, the time resolution is 1 msec, the neutron pulse width is 94 msec, and the pulse interval is 188 msec. The 92 keV prompt γ-ray of Na rises immediately after neutron pulse irradiation and falls after the end of irradiation, whereas the 472 keV decaying γ-ray of 24 m Na (half-life 20 msec) which is an extremely short-lived nuclide γ-rays during irradiation A growth curve of intensity is seen, and it can be seen that the intensity of γ-rays is attenuated with radiation decay after the end of irradiation. As described above, according to the present invention, prompt gamma rays and destructive gamma rays can be clearly separated and measured.

この発明の一実施形態を示す模式図である。It is a schematic diagram which shows one Embodiment of this invention. この発明の実施例である時間分解即発及び壊変ガンマ線スペクトル。2 is a time-resolved prompt and decay gamma-ray spectrum that is an embodiment of the present invention.

符号の説明Explanation of symbols

１ 中性子ビーム ２ 中性子ディスクチョッパー
３ 測定試料 ４ 即発ガンマ線
５ 壊変ガンマ線 ６ ガンマ線検出器
７ ガンマ線測定回路 ８ ガンマ線信号
９ ガンマ線信号 １０ 中性子窓
１１ スタート信号 １２ リストモードファイル
１３ 時間分解即発及び壊変ガンマ線スペクトル
１４ 即発ガンマ線ピーク １５ 壊変ガンマ線ピーク
１６ 壊変ガンマ線
１７ 即発ガンマ線
1 neutron beam 2 neutron disc chopper 3 measurement sample 4 prompt gamma ray 5 decay gamma ray 6 gamma ray detector 7 gamma ray measurement circuit 8 gamma ray signal 9 gamma ray signal 10 neutron window 11 start signal 12 list mode file 13 time-resolved prompt and decay gamma ray spectrum 14 prompt launch Gamma ray peak 15 decayed gamma ray peak 16 decayed gamma ray
17 Prompt gamma rays

Claims (3)

パルス中性子ビームを利用し，中性子パルス発生信号をスタート信号として、スタート信号からの経過時間情報とガンマ線検出事象情報をリストモードで記録し、これを解析して時間分解即発ガンマ線及び壊変ガンマ線スペクトルの測定を行う測定法。   Using pulsed neutron beam, neutron pulse generation signal as start signal, elapsed time information from start signal and gamma ray detection event information are recorded in list mode and analyzed to measure time-resolved prompt gamma ray and decay gamma ray spectrum Measuring method. 中性子照射時の即発ガンマ線スペクトルから中性子未照射時の壊変ガンマ線スペクトルを差し引くことで、即発ガンマ線スペクトルから壊変ガンマ線スペクトル成分を差し引き、即発ガンマ線スペクトルのバックグラウンドを抑制する測走法。   A measurement method that subtracts the decay gamma ray spectrum component from the prompt gamma ray spectrum by subtracting the decay gamma ray spectrum when the neutron is not irradiated from the prompt gamma ray spectrum at the time of neutron irradiation, thereby suppressing the background of the prompt gamma ray spectrum. 中性子パルスビーム周期に対して長半減期の中性子照射中に生成する放射性核種からの壊変ガンマ線ピーク強度を用いて、中性子ビームの在る無しに対応した測定系全体の不感時間の補正を行うガンマ線検出系の不感時間の補正法。








Gamma ray detection that corrects the dead time of the entire measurement system corresponding to the presence or absence of a neutron beam by using the decay gamma ray peak intensity from radionuclides generated during neutron irradiation with a long half-life with respect to the neutron pulse beam period System dead time correction method.








JP2004302928A 2004-10-18 2004-10-18 Discriminational measuring method of prompt and disintegration gamma rays by time list measurement Pending JP2006113010A (en)

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JP2007198749A (en) * 2006-01-23 2007-08-09 Jeol Ltd Measuring data control method, measuring data structure, spectrum regenerating method and surface analyzer
JP2008128808A (en) * 2006-11-21 2008-06-05 Jeol Ltd Data processor

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JPH07301610A (en) * 1992-10-08 1995-11-14 Westinghouse Electric Corp <We> Method and device for obtaining depth profile of concentration of posinous element in soil
JP2000258538A (en) * 1999-03-08 2000-09-22 Natl Inst Of Radiological Sciences Radiation measuring device and method
JP2004125639A (en) * 2002-10-03 2004-04-22 Japan Atom Energy Res Inst Method for correcting dead time of detector in new microanalysis method having integrated multiple gamma ray detection method and radioactivation analysis
JP2004138471A (en) * 2002-10-17 2004-05-13 Japan Atom Energy Res Inst Method for quickly and easily measuring concentration of cadmium contained in minute amount in food by using prompt gamma-ray analysis
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Publication number Priority date Publication date Assignee Title
JPH07301610A (en) * 1992-10-08 1995-11-14 Westinghouse Electric Corp <We> Method and device for obtaining depth profile of concentration of posinous element in soil
JP2000258538A (en) * 1999-03-08 2000-09-22 Natl Inst Of Radiological Sciences Radiation measuring device and method
JP2004125639A (en) * 2002-10-03 2004-04-22 Japan Atom Energy Res Inst Method for correcting dead time of detector in new microanalysis method having integrated multiple gamma ray detection method and radioactivation analysis
JP2004138471A (en) * 2002-10-17 2004-05-13 Japan Atom Energy Res Inst Method for quickly and easily measuring concentration of cadmium contained in minute amount in food by using prompt gamma-ray analysis
JP2004219187A (en) * 2003-01-14 2004-08-05 Japan Atom Energy Res Inst Isotope analysis method in high precision, high s/n, and high efficiency by nuclear isomer generation using laser inverse compton gamma ray

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007198749A (en) * 2006-01-23 2007-08-09 Jeol Ltd Measuring data control method, measuring data structure, spectrum regenerating method and surface analyzer
JP2008128808A (en) * 2006-11-21 2008-06-05 Jeol Ltd Data processor

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