Two energy-varying beam extraction schemes for energy sweeping compact rapid cycling therapy are discussed. One is one-turn (fast) extraction of a ${\mathrm{C}}^{6+}$ bunch from a fast-cycling hadron driver accelerator assisted by an off-momentum bump orbit, in which a combination of a kicker and a septum magnet are fired at a desired timing (or energy). The other is energy sweeping extraction, in which a ${\mathrm{C}}^{5+}$ bunch delivered from the laser ablation ion source is injected and accelerated in the barrier bucket up to the final energy. A fraction of the trapped ${\mathrm{C}}^{5+}$ ions is continuously released from the bucket on the way to the final energy to form a coasting beam over an expected time (or energy) region, and the beam drifts inward in the large flat momentum dispersion region. The drifting ${\mathrm{C}}^{5+}$ beam hits the stripper carbon foil located at the front of the bending magnet and near the inner surface of the vacuum chamber in the large flat dispersion region and is converted to a ${\mathrm{C}}^{6+}$ beam. The combination of the enhanced bending radius and septum magnet allows easy ${\mathrm{C}}^{6+}$ beam extraction by the single septum magnet downstream.

中文翻译：

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大动量偏差和电荷交换辅助变能束提取

讨论了两种用于能量扫描紧凑型快速循环疗法的变能束提取方案。一种是单次（快速）提取${\mathrm{C}}^{6+}$来自快速循环的强子驱动加速器的加速器束，由非动量颠簸轨道辅助，在其中以期望的时间（或能量）发射喷射器和隔垫磁铁。另一个是能量扫描提取，其中${\mathrm{C}}^{5+}$从激光烧蚀离子源输送来的束被注入并在势垒铲斗中加速直至最终能量。被困的一小部分${\mathrm{C}}^{5+}$离子在到达最终能量的过程中不断从铲斗中释放出来，从而在预期的时间（或能量）区域形成惯性滑行束，并且该束在较大的平坦动量分散区域内向内漂移。漂流${\mathrm{C}}^{5+}$ 光束撞击较大的平坦分散区域中位于弯曲磁体前部和真空室内表面附近的剥离剂碳箔，并转换为 ${\mathrm{C}}^{6+}$光束。增强的弯曲半径和隔垫磁铁相结合，使操作简便${\mathrm{C}}^{6+}$ 单个隔片磁铁在下游进行电子束提取。