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Saha, P. K.; 原田 寛之; 金正 倫計; 山本 昌亘; 佐甲 博之
Proceedings of 13th International Conference on Heavy Ion Accelerator Technology (HIAT 2015) (Internet), p.127 - 129, 2016/02
The potential of 3-GeV RCS for accelerating HI has been studied. The importance of HI physics program in J-PARC is being intensively discussed recently. RCS can play the most important role in order to realize HI program in J-PARC. Making no interference with existing and planned facilities that make use of proton beam, an acceleration of as high as more than 1E11 uranium ions of 86+ charge state (
) in the RCS are successfully confirmed without any significant beam losses. The present study can give a strong motivation to step forward in order to realize HI program in J-PARC, which would be definitely another new frontier of physics in J-PARC.
倉島 俊; 宮脇 信正; 柏木 啓次; 福田 光宏*
Proceedings of 13th International Conference on Heavy Ion Accelerator Technology (HIAT 2015) (Internet), 3 Pages, 2015/09
TIARAサイクロトロンでは、イオン種の短時間切換を目的としてカクテルビーム加速技術を開発し、半導体の耐放射線評価試験などに利用している。この技術では、電荷質量比(M/Q)のほぼ等しい複数のイオン種を同時に入射し、サイクロトロンの高いM/Q分解能
(M/Q)/
(M/Q)を利用して単一のイオン種のみを取り出す。今回、カクテルビーム加速技術とビームチョピング技術を組み合わせM/Q分解能を向上させた。これまでサイクロトロンで分離できなかった複数のイオン種について、入射ビームラインのパルス電圧型ビームチョッパーを用いて約1RF周期のパルスビームを入射した場合、加速周波数と回転周波数が同期したイオン種がまず最初に取り出され、取り出し対象外の不純物イオン種はエネルギーゲインが低いために遅れて取り出される。サイクロトロン後段のビームチョッパーを高周波数の正弦波電圧型から低周波数のパルス電圧型に置換え、遅れて取り出される不純物イオンを取り除くことにより対象とするイオン種のみを分離することに成功した。現在までに
Ar
と
Ar
の分離に成功しており、M/Q分解能はこれまでの3,300から25,000へと大幅に向上した。
宮脇 信正; 倉島 俊; 柏木 啓次; 奥村 進; 福田 光宏*
Proceedings of 13th International Conference on Heavy Ion Accelerator Technology (HIAT 2015) (Internet), 3 Pages, 2015/09
Phase bunching in the central region of the JAEA AVF cyclotron for heavy ion acceleration in the third-harmonic mode (
= 3) was studied using both calculation with a simplified geometric trajectory model and measurement of an internal beam phase distribution. The phase bunching for = 3 was compared with that for = 2, where the geometric condition of the central region differs from that for the former. The result of measurement shows that the phase bunching for = 3 was equivalent to that for = 2 when a beam buncher was not used before the acceleration. When the beam buncher was active, however, the phase width for = 3 was larger than that for = 2. The analyses using both the calculation and the measurement indicates that, in order to enhance the phase bunching for = 3, it is necessary to modify the geometric condition of the central region and to increase the ratio of a peak dee-voltage to an extraction voltage of an ion source, which is one of the parameters determining the phase bunching performance.
