Optimizing C4+ and C5+ beams of the Kei2 electron cyclotron resonance ion source using a special gas-mixing technique
Optimizing C4+ and C5+ beams of the Kei2 electron cyclotron resonance ion source using a special gas-mixing technique
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使用特殊的气体混合技术优化 Kei2 电子回旋共振离子源的 C4 和 C5 束
DOI：
10.1063/1.2149372
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
A. Kitagawa
中科院分区：
文献类型：
--
作者：
A. Drentje;M. Muramatsu;A. Kitagawa
使用日本下一个碳治疗设施的原型电子回旋共振离子源进行了一系列测量，以便 (a) 找到产生 C4+ 离子高束流的最佳条件，以及 (b) 研究使用化合物作为原料气的“特殊”气体混合的效果。在这种情况下，对于 C5+ 离子，该效应将表现为高电荷态产生的增加。在“常规”气体混合实验中，众所周知，会发生同位素现象：混合气体的较重同位素会增加束流气体离子高电荷态的产生。在本实验中发现了类似的同位素效应：氘化甲烷（CD4 气体）的 C5+ 束流比常规甲烷（CH4 气体）高约 10%。 “混合气体”D(或H)与C的比率可以通过选择例如丁烷气体来降低；在这种情况下，C5+ 生产的同位素效应甚至更强 (>15%)。对于 C4+ 离子的产生，同位素效应...
With the prototype electron cyclotron resonance ion source for the next carbon therapy facility in Japan a series of measurements has been performed in order (a) to find the best condition for producing high beam currents of C4+ ions, and (b) to study the effect of “special” gas mixing by using a chemical compound as a feed gas. The effect would then appear as an increase in high charge state production in this case of C5+ ions. In “regular” gas-mixing experiments it is well known that an isotopic phenomenon occurs: a heavier isotope of the mixing gas is increasing the production of high charge states of the beam gas ions. A similar isotopic effect has been found in the present experiment: with deuterated methane (CD4 gas) the C5+ beam currents are about 10% higher than with regular methane (CH4 gas). The “mixing-gas” ratio D (or H) to C can be decreased by choosing, e.g., butane gas; in this case the isotopic effect for C5+ production is even stronger (>15%). For production of C4+ ions the isotopic effec...