Energy compensation of slow extracted beams with RF acceleration
Energy compensation of slow extracted beams with RF acceleration
复制标题
通过射频加速对慢速提取光束进行能量补偿
DOI：
10.1016/j.nima.2015.12.044
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Koji Noda
中科院分区：
文献类型：
--
作者：
Tetsuya Fujimoto;Hikaru Souda;Masami Torikoshi;Tatsuaki Kanai;Satoru Yamada;Koji Noda
在传统的碳离子放射治疗设施中，碳离子束通常被加速到最佳能量，通过共振慢速提取方法从同步加速器环中缓慢提取，并最终通过光束输送系统输送给患者。在日本群马大学，一种采用慢速光束提取和光束加速的方法已经被采用。由于该过程的加速成分，该方法略微改变了提取光束的能量，这随后导致水当量长度的残余范围变化约为2mm。然而，这种范围变化并不干扰远端剂量分布与宽束方法，如单束摆动方法。然而，对于铅笔束三维扫描方法，这种范围变化会干扰远端剂量分布，因为这种变化与切片厚度相当。因此，针对铅笔束三维扫描，本文提出了一种针对慢速提取光束的能量补偿方法。这种方法可以通过固定在同步加速器出口通道和等中心之间的可旋转能量吸收装置来控制净能量损失，从而补偿上述能量差异。实验结果表明，光束能量可以保持恒定，正如最初假设的那样。此外，通过优化光束光学，通过实施多重散射效应选项来减少光束尺寸的增长，发现能量吸收器位置显著增强。
In a conventional carbon-ion radiotherapy facility, a carbon-ion beam is typically accelerated up to an optimum energy, slowly extracted from a synchrotron ring by a resonant slow extraction method, and ultimately delivered to a patient through a beam-delivery system. At Japan’s Gunma University, a method employing slow-beam extraction along with beam-acceleration has been adopted. This method slightly alters the extracted-beam’s energy owing to the acceleration component of the process, which subsequently results in a residual-range variation of approximately 2 mm in water-equivalent length. However, this range variation does not disturb a distal dose distribution with broad-beam methods such as the single beam-wobbling method. With the pencil-beam 3D scanning method, however, such a range variation disturbs a distal dose distribution because the variation is comparable to slice thickness. Therefore, for pencil-beam 3D scanning, an energy compensation method for a slow extracted beam is proposed in this paper. This method can compensate for the aforementioned energy variances by controlling net energy losses through a rotatable energy absorber set fixed between the synchrotron exit channel and the isocenter. Experimental results demonstrate that beam energies can be maintained constant, as originally hypothesized. Moreover, energy-absorber positions were found to be significantly enhanced by optimizing beam optics for reducing beam-size growth by implementation of the multiple-scattering effect option.
用于质子治疗的三维束扫描
DOI：
--
发表时间：
1983
期刊：
影响因子：
--
作者：
T. Kanai;K. Kawachi;Hideo Matsuzawa;T. Inada
通讯作者：
T. Inada
影响因子：
--
作者：
BETHE, HA
通讯作者：
BETHE, HA
影响因子：
2
作者：
Noda, Koji;Furukawa, Takuji;Yusa, Ken
通讯作者：
Yusa, Ken