@inproceedings{oai:repo.qst.go.jp:00054839,
 author = {水島, 康太 and 白井, 敏之 and 古川, 卓司 and 佐藤, 眞二 and 岩田, 佳之 and 野田, 耕司 and 内山, 宙志 and 藤澤, 高志 and 水島 康太 and 白井 敏之 and 古川 卓司 and 佐藤 眞二 and 岩田 佳之 and 野田 耕司 and 藤澤 高志},
 book = {Proceedings of PAC09, Vancouver, BC, Canada},
 month = {May},
 note = {A 3D scanning method gated with the patient's respiration has been developed for the HIMAC new treatment facility. The RF-knockout slow-extraction method has been used during scanning irradiation, because of the quick response to beam on/off switching from the synchrotron. However, a small amount of beam that remained just inside the separatrix spill out even without the transverse RF field, which brings the extra dose. We have proposed a method which applies another RF-frequency component matched with the betatron frequency of the particles near the stopband in addition to the original transverse RF field. The particles just inside the separatrix can be selectively extracted during the irradiation; as a result, the extra dose can be also reduced. We measured it with an ion chamber, and could reduce to around 0.4 % compared to the original method.},
 pages = {1318--1320},
 title = {EXTRA DOSE REDUCTION BY OPTIMIZING RF-KO SLOW-EXTRACTION AT HIMAC},
 year = {2009}
}