JP2004093383A

JP2004093383A - Waveform discriminating apparatus

Info

Publication number: JP2004093383A
Application number: JP2002255534A
Authority: JP
Inventors: Hirotaka Sakai; 酒井　宏隆; Koichi Yamada; 山田　公一; Akira Yunoki; 柚木　彰
Original assignee: Toshiba Corp
Current assignee: Toshiba Corp
Priority date: 2002-08-30
Filing date: 2002-08-30
Publication date: 2004-03-25
Anticipated expiration: 2022-08-30
Also published as: JP3980451B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waveform discriminating apparatus for discriminating waveform based on a peak value for every different elapsed-time of an input signal. <P>SOLUTION: The waveform discriminating apparatus is provided with a pulse input section 1; a start signal generation section 2 for generating a start signal by pulse input from the pulse input section 1; a plurality of data acquisition signal generation sections 4, 5, 6 for generating a data acquisition signal s4 at different timing by a delay circuit section 3 each by receiving a signal from the start signal generation section 2; a plurality of peak conversion sections 7, 8, 9; a pattern identification section 10; and an output section 11. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は放射線等の粒子線の測定用装置に係り、特に信号波形を処理する波形弁別装置に関する。
【０００２】
【従来の技術】
放射線検出器などの出力波形信号は入射粒子の線種、エネルギ、位置、方向等によってその最大振幅だけでなく、立ち上がり時間、減衰時間等といった値が異なる。これらを弁別するため、従来では複雑なアナログ的な回路を用いてアナログ的な波形処理により注目する立ち上がり時間や、減衰時間等に相当する信号を振幅に変換して取得していた（例えば特開２０００−６５９３６号公報）。
【０００３】
しかしながら、ノイズの混入防止やタイミング特性の保持など、実際に機器に使用する際には高度なアナログ回路の設計が不可欠であり、その適用先も限られたものであった。
【０００４】
【発明が解決しようとする課題】
上述したように、従来ではアナログ的な回路を用いた波形処理により、立ち上がり時間や減衰時間等に相当する信号を振幅に変換して取得していたため、ノイズの混入防止やタイミング特性の保持など、実際に機器に使用する際には高度なアナログ回路の設計が不可欠であり、その適用先も限られたものであった。
【０００５】
本発明はこのような事情に鑑みてなされたもので、予め定めた複数の時間経過時の波形が有する振幅、すなわち波高をＡ／Ｄ変換し、その波高の組合せを基に波形弁別を行うことで、アナログ的な処理によらない簡便な波形弁別装置を提供することを目的とする。
【０００６】
【課題を解決するための手段】
上述した目的を達成するため、請求項１に係る発明では、パルス入力部と、このパルス入力部からのパルス入力によりスタート信号を発生するスタート信号発生部と、このスタート信号発生部からの信号を受け、それぞれ異なるタイミングでデータ取得信号を生成する複数のデータ取得信号発生部と、これらのデータ取得信号発生部からの信号を受け、波形の各タイミングでの波高の数値への変換を行う複数の波高変換部と、それら変換された数値の組合せをもって波形パターンを識別し、パターンごとの対応した出力部に出力を行うパターン識別部とを備えたことを特徴とする波形弁別装置を提供する。
【０００７】
請求項２に係る発明では、パルス入力部と、このパルス入力部からのパルス入力によりスタート信号を発生するスタート信号発生部と、このスタート信号発生部からの信号を受け波高のデジタル変換の開始信号を予め定められたタイミングにおいて複数回数発生させるデータ取得信号発生部と、このデータ取得信号発生部からの信号を受ける毎に波形の各タイミングでの波高の数値への変換を行う波高変換部と、それら変換された数値の組合せをもって波形パターンを識別し、パターンごとの対応した出力部に出力を行うパターン識別部とを備えたことを特徴とする波形弁別装置を提供する。
【０００８】
請求項３に係る発明では、請求項１または請求項２記載の波形弁別装置において、パターン変換部にて得られた測定タイミングの異なる複数の波高値のうち、ひとつを基準とし、残りの値をその基準値で除し、その値を基に予め定められた値の範囲に応じて対応する出力部に出力を行うことを特徴とする波形弁別装置を提供する。
【０００９】
請求項４に係る発明では、請求項１または請求項２記載の波形弁別装置において、波形弁別装置のパターン変換部にて得られた複数の波高値の組合せを配列として取扱い、その配列と、予め定められている固有の１個または複数の配列との比較等のパターン弁別に従い出力部に出力を行うことを特徴とする波形弁別装置を提供する。
【００１０】
請求項５に係る発明では、請求項１から４までのいずれかに記載の波形弁別装置において、入射した粒子線の種類によって取得する各測定タイミングでの波高値が異なる波形を生じる粒子線検出器を接続することで粒子線の種類ごとの出力を求める手段を備えたことを特徴とする波形弁別装置を提供する。
【００１１】
なお、請求項１〜４に係る発明においては、入射した粒子線の位置によって取得する各測定タイミングでの波高値の組合せが異なる波形を生じる粒子線検出器を接続することで粒子線の入射位置毎に弁別された出力を求めることが望ましい。
【００１２】
また、請求項１〜４に係る発明においては、入射した粒子線の入射方向によって取得する各測定タイミングでの波高値の組合せが異なる波形を生じる粒子線検出器を接続することで粒子線の入射方向毎に弁別された出力を求めることが望ましい。
【００１３】
また、請求項１〜４に係る発明においては、波形弁別装置につながる信号線に、それぞれ取得する各測定タイミングでの波高値の組合せが異なる波形を生じる検出器複数台を同時につなぎ、その波形を弁別することで１本の信号線で複数台の検出器の出力を伝送するこが望ましい。
【００１４】
また、請求項１〜４に係る発明においては、検出器からの信号線をつなぎ、検出器由来の信号と信号線からの雑音など検出器以外の要素による信号とを弁別し、検出器由来の信号のみを計数することが望ましい。
【００１５】
請求項６に係る発明では、請求項３記載の波形弁別部において、二つの波高値を取得する構成とし、先に波形を取得するタイミングを、立ち上がりの早い波形が最大値を取るタイミングとし、次の波形を取得するタイミングを立ち上がりの早い波形がすでに減衰に転じているようなタイミングとなるようにし、この時、先に取得した波高値を後に取得した波高値で除算した値が、立ち上がり時間が二つの波高の取得間隔の時間よりも十分に長ければ除算した値が予め定められた値を超え、立ち上がり時間が二つの波高の取得間隔の時間時間以下であれば予め定められた値以下となることを利用して、立ち上がりの早い信号波形と遅い信号波形とを弁別する手段を備えたことを特徴とする波形弁別装置を提供する。
【００１６】
【発明の実施の形態】
以下、本発明に係る波形弁別装置の実施形態について、図面を参照して具体的に説明する。
【００１７】
第１実施形態（図１）
本実施形態では、異なる経過時間毎の入力信号の波高値をもとに波形弁別を行う波形弁別装置について説明する。
【００１８】
図１に示すように、この波形弁別装置では、パルス入力部１と、このパルス入力部１からのパルス入力ｓ１によりスタート信号ｓ２を発生するスタート信号発生部２と、このスタート信号発生部２からの信号ｓ２を受け、それぞれ遅延回路部３により異なるタイミングでデータ取得信号ｓ３を生成する複数のデータ取得信号発生部（１〜ｎ）４，５，６とを備える。また、複数の波高変換部（１〜ｎ）７，８，９と、パターン識別部１０と、出力部１１とを備える。
【００１９】
そして、データ取得信号発生部４，５，６からの信号ｓ３を受け、複数の波高変換部（１〜ｎ）７，８，９により波形の各タイミングでの波高の数値への変換を行い、それら変換された信号ｓ４による数値の組合せをもってパターン識別部１０により波形パターンを識別し、パターン（例えばパターンＡ，Ｂ，Ｃ）ごとの対応した出力部１１に出力Ｐａ（パターンＡ），Ｐｂ（パターンＢ），Ｐｃ（パターンＣ）が行われる。
【００２０】
このように構成した波形弁別装置によれば、入力信号の異なる経過時間ごとの波高値をもとに、波形の弁別を行うことができる。
【００２１】
第２実施形態（図２）
本実施形態では、予め定められた時間経過後の波高値の組合せを取得することができる波形弁別装置について説明する。
【００２２】
図２に示すように、本実施形態の波形弁別装置は、パルス入力部１と、スタート信号発生部２と、スタート信号発生部２からの信号ｓ２を受けて波高のデジタル変換の開始信号を予め定められた回数ごとに任意の時間間隔にて発生させるデータ取得信号発生部４とを備える。また、データ取得信号発生部４からの信号ｓ４を受ける毎に波高値変換タイミング調整のための遅延回路部３を通った後の波形の各タイミングで波高の数値への変換を行う波高変換部７を備える。
【００２３】
これにより、スタート時間から予め定められた時間経過後の波高値の組合せを取得することができる。それら数値の組合せをもって入射パターンを識別し、パターンごとの対応した端子に出力を行うパターン識別部で構成した波形弁別装置により、波形の弁別を行うことができる。
【００２４】
第３実施形態（図１、図２）
本実施形態では、経過時間の異なる２つ以上の波高値の割合をもとに波形弁別を行う波形弁別装置について説明する。
【００２５】
すなわち、パターン変換部７にて得られた測定タイミングの異なる複数の波高値のうち、ひとつを基準とし、残りの値をその基準値で除し、その値を基に予め定められた値の範囲（実験等を先にしておき、蓄積したデータを使用する）に応じて対応する出力部に出力を行う。
【００２６】
例えば第１実施形態および第２実施形態の波形弁別装置のパターン変換部７において得られた複数の波高値のうち、ｔ_１秒経過後の波高値をＨ_１、ｔ_２経過後の波高値をＨ_２とする。この２つの値より、弁別パラメータＳを以下のように求める。
【００２７】
【数１】
Ｓ＝Ｈ_１／Ｈ_２
このＳの値により、予め各出力端子毎に定められた値の範囲に応じて対応する出力端子に出力を行うことで波形弁別を行う。
【００２８】
第４実施形態
本実施形態では、第１実施形態および第２実施形態の波形弁別装置のパターン変換部において、得られた複数の波高値のうち、ｔ_１，ｔ_２，ｔ_３，…ｔ_ｎ秒経過後の値をそれぞれ、Ｈ_１，Ｈ_２，Ｈ_３，…Ｈ_ｎという値とする。この値を、配列Ｐ＝（Ｈ_１，Ｈ_２，Ｈ_３，…Ｈ_ｎ）という形で取扱う。
【００２９】
また、予め比較配列として、Ｃ_ａ＝（Ｃ_ａ１，Ｃ_ａ２，Ｃ_ａ３，…Ｃ_ａｎ），Ｃ_ｂ＝（Ｃ_ｂ１，Ｃ_ｂ２，Ｃ_ｂ３，…Ｃ_ｂｎ），Ｃ_ｃ＝（Ｃ_ｃ１，Ｃ_ｃ２，Ｃ_ｃ３，…Ｃ_ｃｎ）…Ｃ_ｘ＝（Ｃ_ｘ１，Ｃ_ｘ２，Ｃ_ｘ３，…Ｃ_ｘｎ）といった配列を用意しておく。この比較配列はそれぞれ特定の出力ｃｈと対応がつけられている。
【００３０】
そして、パターンＰと比較配列Ｃ_ｋとの間での距離Ｄ_ｋという値を
【数２】

という形で定義し、このＤ_ｋがもっとも小さくなる比較配列に対応する出力チャンネルに出力を行うことで波形弁別を行う。
【００３１】
本実施形態によれば、経過時間の異なる２つの波高値の割合を基に波形弁別を行う波形弁別装置を求めることができる。
【００３２】
第５実施形態
本実施形態では、第１実施形態の波形弁別装置のパターン変換部において、得られた複数の波高値のうち、ｔ_１，ｔ_２，ｔ_３，…ｔ_ｎ秒経過後の値をそれぞれ、Ｈ_１，Ｈ_２，Ｈ_３，…Ｈ_ｎという値とする。この値を、配列Ｐ＝（Ｈ_１，Ｈ_２，Ｈ_３，…Ｈ_ｎ）という形で取扱う。
【００３３】
また、予め比較配列として、Ｃ＝（Ｃ_１，Ｃ_２，Ｃ_３，…Ｃ_ｎ）という配列を用意しておく。そして、パターンＰと比較配列Ｃとの間の内積Ｍを
【数３】

という形で定義する。このＭの値により、予め各出力端子毎に定められた値の範囲に応じて対応する出力端子に出力を行うことで波形弁別を行う。
【００３４】
本実施形態によれば、経過時間の異なる２つの波高値の割合を基に波形弁別を行う波形弁別装置を求めることができる。
【００３５】
第６実施形態
本実施形態では、経過時間の異なる複数の波高値の組合せと予め定められている値との比較によって、波形弁別を行う波形弁別装置について説明する。
【００３６】
第１実施形態および第２実施形態の波形弁別装置のパターン変換部において、得られた複数の波高値のうち、ｔ_１，ｔ_２，ｔ_３，…ｔ_ｎ秒経過後の値をそれぞれ、Ｈ_１，Ｈ_２，Ｈ_３，…Ｈ_ｎという値とする。この値を、配列Ｐ＝（Ｈ_１，Ｈ_２，Ｈ_３，…Ｈ_ｎ）という形で取扱う。
【００３７】
このパターンＰを予めパターンに応じて出力ｃｈを決定するように最適化された階層型ニューラルネットワーク等のパターン識別アルゴリズムへと入力しその応答に従い定められた出力ｃｈに出力を行う。
【００３８】
本実施形態によれば、経過時間の異なる複数の波高値の組合せと予め定められている値との比較・演算によって、パターン弁別を行うことができる。
【００３９】
第７実施形態
本実施形態では、請求項１〜３の波形弁別装置に、入射した粒子線の種類によって波形の異なる粒子線検出器を接続することで粒子線の種類毎に弁別された出力を行う粒子線検出装置について説明する。
【００４０】
第１〜第６実施形態の波形弁別装置に、入射した粒子線の種類によってそれぞれ取得する各測定タイミングでの波高値の組合せが異なるような粒子線検出器を接続することで粒子線の種類毎に弁別された出力を求める。入射した粒子の種類により波形の異なる粒子線検出器としては、ＺｎＳ（Ａｇ）の薄い層と、プラスチックシンチレータの厚い層を重ね合わせ、ひとつの光センサにて検出する形の粒子線検出器等が挙げられる。
【００４１】
本実施形態によれば、波形弁別装置に入射した粒子線の種類によって波形の異なる粒子線検出器を接続することで，粒子線の種類毎のカウントを出力することができる。
【００４２】
第８実施形態
本実施形態では、第１実施形態〜第３実施形態の波形弁別装置に、入射した粒子線の位置によって波形の異なる粒子線検出器を接続することで粒子線の入射位置毎に弁別された出力を行う粒子線検出装置について説明する。
【００４３】
第１〜第６実施形態の波形弁別装置に、入射した粒子線の位置によってそれぞれ取得する各測定タイミングでの波高値の組合せが異なるような粒子線検出器を接続することで粒子線の位置毎に弁別された出力を求める。粒子線の入射位置により波形の異なる粒子線検出器としては、抵抗性の芯線を用い、片側をコンデンサを介して接地させ、もう一端から信号を読み出す片側読出し位置検出型比例計数管などが挙げられる。
【００４４】
本実施形態によれば、波形弁別装置に入射した粒子線の位置によって波形の異なる粒子線検出器を接続することで、粒子線の入射位置毎に弁別された出力を行うことができる。
【００４５】
第９実施形態
本実施形態では、第１実施形態〜第３実施形態の波形弁別装置に、入射した粒子線の入射方向によって波形の異なる粒子線検出器を接続することで粒子線の入射方向毎に弁別された出力を行う粒子線検出装置について説明する。
【００４６】
第１〜第６実施形態の波形弁別装置に、入射した粒子線の入射方向によってそれぞれ取得する各測定タイミングでの波高値の組合せが異なるような粒子線検出器を接続することで粒子線の入射方向毎に弁別された出力を求める。粒子線の入射方向により波形の異なる粒子線検出器としては同軸型の電極配置をした半導体検出器などが挙げられる。
【００４７】
本実施形態によれば、入射した粒子線の入射方向によって波形の異なる粒子線検出器を接続することで、粒子線の入射方向毎に弁別された出力を行うことができる。
【００４８】
第１０実施形態
本実施形態では、第１実施形態〜第６実施形態の波形弁別装置に接続される信号線に、それぞれ出力波形の異なる検出器複数台を同時に接続し、その波形を弁別することで１本の信号線で複数台の検出器の出力を伝送する信号計数装置について説明する。
【００４９】
すなわち、第１〜第６実施形態の波形弁別装置につながる信号線に、それぞれ取得する各測定タイミングでの波高値の組合せが異なるような検出器複数台を同時に接続し、その波形を弁別することで、１本の信号線で複数台の検出器の出力を伝送することができる。
【００５０】
本実施形態によれば、波形弁別装置につながる信号線に、それぞれ出力波形の異なる検出器複数台を同時に接続し、その波形を弁別することで１本の信号線で複数台の検出器の出力を伝送することができる。
【００５１】
第１１実施形態
本実施形態では、第１実施形態〜第６実施形態の波形弁別装置に検出器からの信号線をつなぎ、検出器由来の信号と、信号線からの雑音など検出器以外の要素による信号とを弁別し、検出器由来の信号のみを計数する信号計数装置について説明する。
【００５２】
すなわち、雑音等のノイズ対応パターンは予め知ることができるので、このノイズパターンを予め蓄積しておき、このノイズパターンと検出器のパターンとを比較する。
【００５３】
このように、第１〜第６実施形態の波形弁別装置により、接続された検出器から出力される信号波形のパターンのみを弁別し、計数することで、接続された検出器によらない雑音等の影響を除去することができる。
【００５４】
本実施形態によれば、検出器由来の信号と、信号線からの雑音など検出器以外の要素による信号とを弁別し、検出器由来の信号のみを計数することができる。
【００５５】
第１２実施形態（図３）
本実施形態では、予め設定した時間より、立ち上がり時間が早い波形と遅い波形を弁別する波形弁別装置について説明する。図３は、縦軸に波高値、横軸に時間を表した２種類の入力信号波形を示したものであり、上段の曲線は立ち上がりの早い波形Ａ、下段の曲線は立ち上がりの遅い波形Ｂを表している。
【００５６】
図３に示すように、本実施形態では、立ち上がりの早い波形Ａと遅い波形Ｂとを弁別するために、第３実施形態における二つの波高値を取得する構成とし、先に波形を取得するタイミングを立ち上がりの早い波形Ａが最大値を取るタイミングＴ１とし、次の波形Ｂを取得するタイミングを立ち上がりの早い波形Ａがすでに減衰に転じているようなタイミングＴ２となるようにする。
【００５７】
この時、先に取得した波高値Ｈ１ａ、Ｈ１ｂを後に取得した波高値Ｈ２ａ，Ｈ２ｂで除算した値が、立ち上がり時間が短ければ除算した値が予め定められた値を超え、立ち上がり時間長ければ予め定められた値以下となることを利用して、立ち上がりの早い信号波形と遅い信号波形を弁別することができる。
【００５８】
例えば、一般的な有機シンチレータの出力信号の立ち上がり時間が数十ナノ秒であり、一般的な無機シンチレータの出力信号の立ち上がり時間が数マイクロ秒程度であることから、薄い無機シンチレータ層の下に厚い有機シンチレータ層を張り合わせ、両者からの出力を単一の光センサで電気信号に変換する構成とした場合、１回目のデータ取得を信号が立ち上がり始めてから数十ナノ秒程度経過したタイミングとし、２回目のデータ取得をそれから１マイクロ秒程度以上後のタイミングとして上記の考え方で弁別することで、無機シンチレータ層で主にエネルギが吸収され立ち上がりの遅い信号を発生させるアルファ線と、有機シンチレータ層で主にエネルギが吸収され、立ち上がりの早い信号を発生させる電子線との弁別を行うことができる。
【００５９】
本実施形態によれば、予め設定した時間より、立ち上がり時間が早い波形と遅い波形を弁別する波形弁別装置を求めることができる。
【００６０】
【発明の効果】
以上説明したように、本発明によれば、予め定めた複数の時間経過時の波高をＡ／Ｄ変換し、その波高の組合せを基に波形弁別を行うことで、アナログ的な処理によらない簡便な波形弁別装置を提供することができる。
【図面の簡単な説明】
【図１】本発明の第１実施形態を示す処理ブロックの概略図。
【図２】本発明の第２実施形態を示す処理ブロックの概略図。
【図３】本発明の第１２実施形態を示す処理方法についての線図。
【符号の説明】
１…パルス入力部、２…スタート信号発生部、３…遅延回路部、４，５，６…データ取得信号発生部、７，８，９…波高変換部、１０…パターン識別部、１１…出力部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an apparatus for measuring particle beams such as radiation, and more particularly to a waveform discriminating apparatus for processing a signal waveform.
[0002]
[Prior art]
The output waveform signal of the radiation detector or the like differs not only in the maximum amplitude but also in the value such as the rise time and the decay time depending on the line type, energy, position, direction, and the like of the incident particle. In order to discriminate these, conventionally, a signal corresponding to a rising time, a decay time, or the like, which is of interest by analog waveform processing using a complex analog circuit, is converted into an amplitude and acquired (for example, 2000-65936).
[0003]
However, in actual use in equipment, such as prevention of noise contamination and retention of timing characteristics, advanced analog circuit design is indispensable, and its application is limited.
[0004]
[Problems to be solved by the invention]
As described above, conventionally, signals corresponding to the rise time, the decay time, and the like are converted into amplitudes and acquired by waveform processing using an analog circuit, so that noise mixing is prevented and timing characteristics are retained. In actual use in equipment, advanced analog circuit design is indispensable, and its application has been limited.
[0005]
The present invention has been made in view of such circumstances, and performs A / D conversion of an amplitude of a predetermined plurality of elapsed time waveforms, that is, a wave height, and performs waveform discrimination based on a combination of the wave heights. Therefore, an object of the present invention is to provide a simple waveform discriminating apparatus that does not rely on analog processing.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, in the invention according to claim 1, a pulse input unit, a start signal generation unit that generates a start signal by pulse input from the pulse input unit, and a signal from the start signal generation unit And a plurality of data acquisition signal generators that generate data acquisition signals at different timings, and a plurality of data acquisition signal generators that receive signals from these data acquisition signal generators and convert waveforms into numerical values of wave height at each timing. A waveform discriminating apparatus comprising: a wave height converting unit; and a pattern identifying unit that identifies a waveform pattern based on a combination of the converted values and outputs the waveform pattern to a corresponding output unit for each pattern.
[0007]
In the invention according to claim 2, a pulse input unit, a start signal generation unit that generates a start signal by a pulse input from the pulse input unit, and a start signal for receiving a signal from the start signal generation unit and converting a wave height into a digital signal A data acquisition signal generating unit that generates a plurality of times at a predetermined timing, and a wave height converting unit that converts a waveform into a numerical value of a wave height at each timing each time a signal is received from the data obtaining signal generating unit, There is provided a waveform discriminating apparatus comprising: a pattern identification unit that identifies a waveform pattern based on a combination of the converted numerical values and outputs the waveform pattern to an output unit corresponding to each pattern.
[0008]
According to a third aspect of the present invention, in the waveform discriminating apparatus according to the first or second aspect, one of a plurality of peak values having different measurement timings obtained by the pattern conversion unit is used as a reference, and the remaining values are set to the remaining values. A waveform discriminating device is provided which divides by a reference value and outputs to a corresponding output unit in accordance with a predetermined value range based on the value.
[0009]
In the invention according to claim 4, in the waveform discriminating apparatus according to

claim

1 or 2, a combination of a plurality of peak values obtained by the pattern conversion unit of the waveform discriminating apparatus is handled as an array, Provided is a waveform discriminating device which outputs to an output unit in accordance with pattern discrimination such as comparison with one or a plurality of predetermined unique arrays.
[0010]
According to a fifth aspect of the present invention, in the waveform discriminating apparatus according to any one of the first to fourth aspects, a particle detector that generates a waveform having different peak values at each measurement timing acquired according to the type of the incident particle beam. And a means for obtaining an output for each type of particle beam by connecting the waveform discriminator.
[0011]
In the invention according to claims 1 to 4, the particle beam incident position is connected by connecting a particle beam detector that generates a waveform in which the combination of peak values at each measurement timing obtained according to the position of the incident particle beam produces a different waveform. It is desirable to obtain an output that is discriminated every time.
[0012]
Further, in the inventions according to claims 1 to 4, the particle beam incidence is achieved by connecting a particle beam detector which generates a waveform in which the combination of peak values at each measurement timing obtained according to the incident direction of the incident particle beam produces a different waveform. It is desirable to obtain an output that is discriminated for each direction.
[0013]
Further, in the invention according to claims 1 to 4, a plurality of detectors that generate waveforms having different combinations of peak values at each measurement timing to be obtained are simultaneously connected to a signal line connected to the waveform discriminator, and the waveform is connected. It is desirable to transmit the outputs of a plurality of detectors by one signal line by performing discrimination.
[0014]
In the invention according to claims 1 to 4, the signal line from the detector is connected to discriminate the signal derived from the detector from the signal derived from elements other than the detector such as noise from the detector and the noise from the signal line. It is desirable to count only the signals.
[0015]
In the invention according to claim 6, in the waveform discriminating unit according to claim 3, the configuration is such that two peak values are acquired, the timing at which the waveform is acquired first is the timing at which the waveform with the fast rise takes the maximum value, The waveform acquisition timing is set so that the waveform with the fastest rise has already turned into attenuation.At this time, the value obtained by dividing the previously acquired peak value by the later acquired peak value is the rise time. If the time is sufficiently longer than the time between the acquisitions of the two wave heights, the divided value exceeds the predetermined value, and if the rise time is equal to or less than the time of the time between the acquisitions of the two wave heights, it becomes equal to or less than the predetermined value. The present invention provides a waveform discriminating apparatus characterized by comprising means for discriminating between a signal waveform having an early rise and a signal waveform having a late rise.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of a waveform discrimination device according to the present invention will be specifically described with reference to the drawings.
[0017]
First embodiment (FIG. 1)
In the present embodiment, a waveform discrimination device that performs waveform discrimination based on peak values of an input signal at different elapsed times will be described.
[0018]
As shown in FIG. 1, in this waveform discriminating apparatus, a pulse input unit 1, a start signal generation unit 2 for generating a start signal s2 by a pulse input s1 from the pulse input unit 1, and a start signal generation unit 2 And a plurality of data acquisition signal generators (1 to n) 4, 5, and 6, which respectively generate the data acquisition signal s3 at different timings by the delay circuit unit 3. Further, it includes a plurality of wave height conversion units (1 to n) 7, 8, and 9, a pattern identification unit 10, and an output unit 11.
[0019]
Then, upon receiving the signal s3 from the data

acquisition signal generators

4, 5, and 6, the plurality of wave height converters (1 to n) 7, 8, and 9 convert the wave height to a numerical value at each timing of the waveform, A waveform pattern is identified by the pattern identification unit 10 based on a combination of numerical values based on the converted signal s4, and outputs Pa (pattern A) and Pb (pattern) are output to the corresponding output unit 11 for each pattern (for example, patterns A, B, and C). B) and Pc (pattern C) are performed.
[0020]
According to the waveform discrimination device configured as described above, it is possible to discriminate the waveform based on the peak values of the input signal at different elapsed times.
[0021]
Second embodiment (FIG. 2)
In the present embodiment, a waveform discriminating apparatus capable of acquiring a combination of peak values after a predetermined time has elapsed will be described.
[0022]
As shown in FIG. 2, the waveform discriminating apparatus according to the present embodiment receives a pulse input unit 1, a start signal generating unit 2, and a signal s2 from the start signal generating unit 2 to generate a start signal of a digital conversion of a wave height in advance. A data acquisition signal generator 4 that generates the data at an arbitrary time interval at a predetermined number of times. Also, every time the signal s4 is received from the data acquisition signal generator 4, the wave height converter 7 converts the wave height after passing through the delay circuit unit 3 for adjusting the wave height conversion timing into a numerical value of the wave height at each timing. Is provided.
[0023]
This makes it possible to acquire a combination of peak values after a lapse of a predetermined time from the start time. Waveform discrimination can be performed by a waveform discriminating device constituted by a pattern discriminating unit that discriminates an incident pattern based on a combination of these numerical values and outputs the pattern to a corresponding terminal for each pattern.
[0024]
Third embodiment (FIGS. 1 and 2)
In the present embodiment, a waveform discrimination device that performs waveform discrimination based on the ratio of two or more peak values having different elapsed times will be described.
[0025]
That is, one of a plurality of peak values having different measurement timings obtained by the pattern conversion unit 7 is set as a reference, the remaining value is divided by the reference value, and a range of a value predetermined based on the value is obtained. The output is performed to the corresponding output unit according to (experiment or the like is used first, and the accumulated data is used).
[0026]
For example among the plurality of peak values obtained in the conversion part 7 of the waveform discriminator of the first embodiment and the second embodiment, the peak value after a lapse of t ₁ seconds the peak value of H _1, t ₂ after and H _2. From these two values, the discrimination parameter S is obtained as follows.
[0027]
(Equation 1)

S

₌ _H 1 / H ₂
Waveform discrimination is performed by outputting to the corresponding output terminal according to the value range determined in advance for each output terminal based on the value of S.
[0028]
Fourth embodiment In the present embodiment, of the plurality of peak values obtained in the pattern conversion unit of the waveform discriminating apparatus of the first embodiment and the second embodiment, t ₁ , t ₂ , t _3. , ... respectively the value after lapse of _{t n} _{_{_{s, H 1, H 2, H}}} 3, ... and a value of _{H n.} This value sequence _{_{_{P = (H 1, H 2}}} , H 3, ... H n) handled in the form of.
[0029]
In addition, C _a = (C _a1 , C _a2 , C _a3 ,... C _an ), C _b = (C _b1 , C _b2 , C _b3 ,... C _bn ), C _c = (C _c1 , C a) _{_{_{_{C c2, C c3, ... C}}}} cn) ... C x = (C x1, C x2, C x3, are prepared to ... _{C xn)} such as array. Each of the comparison arrays is associated with a specific output channel.
[0030]
Then, the value of the distance D _k between the pattern P and the comparison array C _k is given by:

The waveform discrimination is performed by outputting to the output channel corresponding to the comparison array in which _Dk becomes the smallest.
[0031]
According to the present embodiment, a waveform discrimination device that performs waveform discrimination based on the ratio of two peak values having different elapsed times can be obtained.
[0032]
In the fifth embodiment <br/> present embodiment, the pattern conversion section of the waveform discrimination apparatus of the first embodiment, among the plurality of pulse height values _{obtained, t 1, t 2, t} 3, ... t n seconds each value after elapse _{_{_{of, H 1, H 2, H}}} 3, ... and a value of _{H n.} This value sequence _{_{_{P = (H 1, H 2}}} , H 3, ... H n) handled in the form of.
[0033]
Also, an array C = (C ₁ , C ₂ , C ₃ ,... C _n ) is prepared in advance as a comparison array. Then, the inner product M between the pattern P and the comparison array C is expressed as

Is defined in the form Waveform discrimination is performed by outputting to the corresponding output terminal in accordance with the value range determined in advance for each output terminal based on the value of M.
[0034]
According to the present embodiment, a waveform discrimination device that performs waveform discrimination based on the ratio of two peak values having different elapsed times can be obtained.
[0035]
Sixth Embodiment In the present embodiment, a waveform discrimination device that performs waveform discrimination by comparing a combination of a plurality of peak values having different elapsed times with a predetermined value will be described.
[0036]
In the pattern conversion section of the waveform discriminator of the first embodiment and the second embodiment, among the plurality of pulse height values _{obtained, t 1, t 2, t} 3, ... t n seconds after the lapse of values, respectively, H _{_{_{1, H 2, H 3,}}} ... and a value of _{H n.} This value sequence _{_{_{P = (H 1, H 2}}} , H 3, ... H n) handled in the form of.
[0037]
The pattern P is input to a pattern identification algorithm such as a hierarchical neural network optimized in advance so as to determine an output channel according to the pattern, and output to a predetermined output channel according to a response.
[0038]
According to the present embodiment, pattern discrimination can be performed by comparing and calculating a combination of a plurality of peak values having different elapsed times and a predetermined value.
[0039]
Seventh embodiment In this embodiment, a particle beam detector having a different waveform depending on the type of the incident particle beam is connected to the waveform discriminating device according to any one of claims 1 to 3, thereby discriminating each type of the particle beam. A particle beam detection device that outputs the output will be described.
[0040]
By connecting the particle discriminator having different combinations of peak values at each measurement timing to be obtained depending on the type of the incident particle beam to the waveform discriminating apparatus of the first to sixth embodiments, the type of the particle beam is different. The output discriminated by As a particle beam detector having a different waveform depending on the type of incident particles, there is a particle beam detector in which a thin layer of ZnS (Ag) and a thick layer of a plastic scintillator are overlapped and detected by one optical sensor. No.
[0041]
According to the present embodiment, by connecting particle beam detectors having different waveforms depending on the type of particle beam incident on the waveform discriminating apparatus, it is possible to output a count for each type of particle beam.
[0042]
Eighth Embodiment In this embodiment, a particle beam detector having a different waveform depending on the position of an incident particle beam is connected to the waveform discriminating apparatus of the first to third embodiments. A particle beam detection device that performs an output that is discriminated for each incident position will be described.
[0043]
By connecting the particle discriminator having different combinations of peak values at each measurement timing to be obtained depending on the position of the incident particle beam to the waveform discriminating apparatus of the first to sixth embodiments, the position of the particle beam can be changed. The output discriminated by Examples of the particle beam detector having a different waveform depending on the incident position of the particle beam include a one-side reading position detection type proportional counter using a resistive core wire, grounding one side via a capacitor, and reading a signal from the other side. .
[0044]
According to the present embodiment, by connecting a particle beam detector having a different waveform depending on the position of the particle beam incident on the waveform discriminating apparatus, it is possible to perform an output discriminated for each particle beam incident position.
[0045]
Ninth embodiment In the ninth embodiment, a particle beam detector having a different waveform depending on the incident direction of an incident particle beam is connected to the waveform discriminating apparatus according to the first to third embodiments. A particle beam detector that performs an output that is discriminated for each incident direction will be described.
[0046]
Particle beam incidence is performed by connecting the particle discriminator having different combinations of peak values at each measurement timing to be obtained depending on the incident direction of the incident particle beam to the waveform discriminating apparatuses of the first to sixth embodiments. The output discriminated for each direction is obtained. Examples of the particle beam detector having a different waveform depending on the incident direction of the particle beam include a semiconductor detector having a coaxial electrode arrangement.
[0047]
According to the present embodiment, by connecting a particle beam detector having a different waveform depending on the incident direction of the incident particle beam, it is possible to perform an output that is discriminated for each incident direction of the particle beam.
[0048]
Tenth embodiment In this embodiment, a plurality of detectors having different output waveforms are simultaneously connected to signal lines connected to the waveform discriminating apparatuses of the first to sixth embodiments, respectively. A signal counting device that transmits the outputs of a plurality of detectors by one signal line by discriminating the signal lines will be described.
[0049]
That is, a plurality of detectors having different combinations of peak values at each measurement timing to be obtained are simultaneously connected to a signal line connected to the waveform discriminating apparatus of the first to sixth embodiments, and the waveform is discriminated. Thus, the outputs of a plurality of detectors can be transmitted by one signal line.
[0050]
According to the present embodiment, a plurality of detectors having different output waveforms are simultaneously connected to the signal lines connected to the waveform discriminating apparatus, and the waveforms are discriminated, so that the output of the plurality of detectors can be performed by one signal line. Can be transmitted.
[0051]
Eleventh embodiment In this embodiment, a signal line from a detector is connected to the waveform discriminating apparatus of the first to sixth embodiments, and a signal derived from the detector and noise from the signal line are detected. A signal counting device that discriminates signals from elements other than the detector and counts only signals derived from the detector will be described.
[0052]
That is, since a noise-corresponding pattern such as noise can be known in advance, this noise pattern is stored in advance, and this noise pattern is compared with the pattern of the detector.
[0053]
As described above, the waveform discriminating apparatus according to the first to sixth embodiments discriminates only the pattern of the signal waveform output from the connected detector and counts the pattern so that noise or the like not depending on the connected detector. Can be eliminated.
[0054]
According to the present embodiment, it is possible to discriminate a signal originating from the detector from a signal originating from an element other than the detector, such as noise from a signal line, and count only the signal originating from the detector.
[0055]
Twelfth embodiment (FIG. 3)
In the present embodiment, a waveform discriminating apparatus that discriminates between a waveform whose rise time is earlier and a waveform whose delay is later than a preset time will be described. FIG. 3 shows two types of input signal waveforms in which the vertical axis represents the peak value and the horizontal axis represents the time. The upper curve shows a waveform A with a fast rise, and the lower curve shows a waveform B with a slow rise. Represents.
[0056]
As shown in FIG. 3, in the present embodiment, in order to discriminate between a waveform A with a fast rise and a waveform B with a slow rise, the configuration is such that two peak values are acquired in the third embodiment, and the timing of acquiring the waveform first Is the timing T1 at which the waveform A with the fast rise takes the maximum value, and the timing at which the next waveform B is acquired is the timing T2 at which the waveform A with the fast rise has already turned to attenuation.
[0057]
At this time, the value obtained by dividing the previously acquired peak values H1a and H1b by the later acquired peak values H2a and H2b is greater than a predetermined value if the rise time is short, and is predetermined if the rise time is long. Utilizing the fact that the signal value is equal to or less than the given value makes it possible to discriminate a signal waveform having a fast rise from a signal waveform having a slow rise.
[0058]
For example, since the rise time of the output signal of a general organic scintillator is several tens of nanoseconds, and the rise time of the output signal of a general inorganic scintillator is about several microseconds, a thick layer is formed under a thin inorganic scintillator layer. In the case where the organic scintillator layers are laminated and the output from both are converted into an electric signal by a single optical sensor, the first data acquisition is performed at a timing several tens of nanoseconds after the signal starts rising, and the second data acquisition is performed. The data acquisition of the above is discriminated based on the above-mentioned concept as a timing of about 1 microsecond or more after that, so that the energy is mainly absorbed by the inorganic scintillator layer, and the alpha ray which generates a signal with a slow rise, and the organic scintillator layer mainly Energy can be absorbed and discriminated from an electron beam that generates a signal with a fast rise. That.
[0059]
According to the present embodiment, it is possible to obtain a waveform discriminating apparatus that discriminates between a waveform having a rise time earlier and a waveform having a later rise time than a preset time.
[0060]
【The invention's effect】
As described above, according to the present invention, A / D conversion is performed on the wave heights at the lapse of a plurality of predetermined times, and waveform discrimination is performed based on a combination of the wave heights, so that analog processing is not performed. A simple waveform discriminating apparatus can be provided.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a processing block showing a first embodiment of the present invention.
FIG. 2 is a schematic diagram of a processing block showing a second embodiment of the present invention.
FIG. 3 is a diagram illustrating a processing method according to a twelfth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Pulse input part, 2 ... Start signal generation part, 3 ... Delay circuit part, 4,5,6 ... Data acquisition signal generation part, 7,8,9 ... Crest height conversion part, 10 ... Pattern identification part, 11 ... Output Department.

Claims

A pulse input unit, a start signal generation unit that generates a start signal in response to a pulse input from the pulse input unit, and a plurality of data acquisition units that receive a signal from the start signal generation unit and generate data acquisition signals at different timings. A signal generation unit, a plurality of peak height conversion units that receive signals from these data acquisition signal generation units and convert the waveforms into numerical values of the wave height at each timing, and form a waveform pattern by combining the converted numerical values. A waveform discriminator comprising: a pattern discriminator for discriminating and outputting to a corresponding output unit for each pattern.

A pulse input unit, a start signal generation unit that generates a start signal in response to a pulse input from the pulse input unit, and a start signal for receiving a signal from the start signal generation unit and converting a wave height into a digital signal at a predetermined timing. A data acquisition signal generating unit to generate a number of times, a wave height converting unit that converts a waveform into a numerical value of a wave height at each timing each time a signal from the data obtaining signal generating unit is received, and a combination of the converted numerical values. A waveform discriminating device comprising: a pattern identifying unit that identifies a waveform pattern and outputs the waveform pattern to an output unit corresponding to the pattern.

3. The waveform discriminating apparatus according to claim 1, wherein one of a plurality of peak values having different measurement timings obtained by the pattern converter is set as a reference, and the remaining value is divided by the reference value. A waveform discriminating device for outputting to a corresponding output unit in accordance with a predetermined value range based on the value.

3. The waveform discriminating apparatus according to claim 1, wherein a combination of a plurality of peak values obtained by the pattern conversion unit of the waveform discriminating apparatus is handled as an array, and the array is combined with a predetermined unique one. Alternatively, a waveform discriminating device outputs to an output unit in accordance with pattern discrimination such as comparison with a plurality of arrays.

The waveform discriminating apparatus according to any one of claims 1 to 4, wherein a particle beam detector that generates a waveform having a different peak value at each measurement timing obtained according to the type of the incident particle beam is connected. A waveform discriminating device comprising means for obtaining an output for each type.

4. The waveform discriminating unit according to claim 3, wherein two peak values are acquired, a timing at which a waveform is acquired first is a timing at which a waveform having a fast rise takes a maximum value, and a timing at which a next waveform is acquired is set at a rise timing. The timing at which the earlier waveform has already turned into attenuation has become the timing, and the value obtained by dividing the previously acquired peak value by the later acquired peak value is the rise time of the interval between the two peak heights. If the value is sufficiently longer than the divided value exceeds the predetermined value, and the rise time is equal to or less than the predetermined value if the rise time is equal to or less than the time interval of the acquisition interval of the two crests, the rise time is used. A waveform discriminating device comprising means for discriminating between an early signal waveform and a late signal waveform.