Multiharmonic rf feedforward system for beam loading compensation in wide-band cavities of a rapid cycling synchrotron
Multiharmonic rf feedforward system for beam loading compensation in wide-band cavities of a rapid cycling synchrotron
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用于快速循环同步加速器宽带腔中光束负载补偿的多谐波射频前馈系统
DOI：
10.1103/physrevstab.14.051004
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发表时间：
2011
影响因子：
--
通讯作者：
K. Hasegawa
中科院分区：
文献类型：
--
作者：
F. Tamura;Masanobu Yamamoto;C. Ohmori;A. Schnase;M. Yoshii;M. Nomura;M. Toda;T. Shimada;K. Hara;K. Hasegawa
为了在日本质子加速器研究综合体（J-PARC）的3GeV快循环同步加速器（RCS）中加速极强质子，在射频加速腔中实现了束流负载补偿。J-PARC雷达散射截面（RCS）采用了具有宽带频率响应的磁合金加载腔。宽带MA腔中的尾波电压不仅包括基本加速射频的分量，还包括高次谐波。我们开发了一个多谐波前馈补偿系统，它可以处理最重要的三个谐波（$h= 2，4，6 $）。阐述了多谐波前馈的作用。在加速周期期间用于消除唤醒电压的幅度和相位图案的调整不是微不足道的。我们开发了前馈的调试方法。我们描述的情况下，没有和驱动加速射频的方法。雷达散射截面中11个空腔的系统调试是成功的。介绍了前馈补偿在束流运行中的调试结果和有益效果。
For the acceleration of very high intensity protons in the 3 GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the beam loading compensation in the rf accelerating cavities is implemented. The magnetic-alloy (MA) loaded cavities, which have a wide-band frequency response, are employed in the J-PARC RCS. The wake voltage in the wide-band MA cavity consists of not only a component of the fundamental accelerating rf, but also the higher harmonics. We developed a multiharmonic feedforward compensation system, which handles the most important three harmonics ($h=2,4,6$). The function of the multiharmonic feedforward is described. Adjustments of the amplitude and phase patterns for the cancellation of the wake voltage during the acceleration period are not trivial. We developed the commissioning methodology of the feedforward. We describe the methodology in the cases without and with driving the accelerating rf. The commissioning of the systems for 11 cavities in the RCS was successful. We describe the commissioning results and the beneficial effects of the feedforward compensation in the beam operation.