Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1682952 | Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms | 2011 | 6 Pages |
Abstract
In order to realize a precise dose distribution in heavy-ion cancer therapy, high beam stability is required for the accelerator complex. Owing to load fluctuation caused by the upper ring, which is one of the two rings in HIMAC, current dips of â5-10 Hz were observed in the power supply for the bending/quadrupole magnet of the other lower ring. The parameters of the beam stability, such as the spill variation, the beam position, and the size, were adversely affected by the current dips. In order to suppress these current dips, we developed a new feed-forward system in the magnet power supply. We verified the performance of the feed-forward system by measuring the suppression of the current dips. We also performed beam experiments to measure the variation of the horizontal tune and the structure of the beam spill, which is slowly extracted by the resonance method. The experimental result showed that the current dips were successfully reduced by the system to ÎI/I â¼Â 10â6. It was also confirmed that the horizontal tune and the spill structure could be stabilized by the current dip suppression.
Related Topics
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Materials Science
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Authors
K. Katagiri, T. Furukawa, K. Mizushima, H. Uchiyama, E. Takeshita, T. Himukai, S. Sato, Y. Iwata, T. Shirai, K. Noda,