2.5 MeV CW 4-vane RFQ accelerator design for BNCT applications
2.5 MeV CW 4-vane RFQ accelerator design for BNCT applications
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DOI：
10.1016/j.nima.2017.11.042
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发表时间：
2018-03
影响因子：
1.4
通讯作者：
Xiaowen Zhu;Hu Wang;Yuanrong Lu;Zhi Wang;K. Zhu;Y. Zou;Zhiyu Guo
中科院分区：
文献类型：
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作者：
Xiaowen Zhu;Hu Wang;Yuanrong Lu;Zhi Wang;K. Zhu;Y. Zou;Zhiyu Guo
摘要 硼中子捕获疗法 (BNCT) 利用 10 B+ n→ 7 Li+ 4 He 反应高度选择性地破坏癌细胞，因此在癌症治疗中前景光明。对于治疗恶性脑肿瘤、头颈癌、黑色素瘤、肝癌等，具有比传统方法更满意的治疗效果。 CW 4 叶片 RFQ 运行频率为 162.5 MHz，可将 20 mA 质子束加速至 2.5 MeV，轰击液态锂靶材，以软中子能谱产生中子。快中子产额约为1.73×10 13 n∕ s。我们初步开发并优化了 2.5 MeV 质子束 7 Li (p, n) 7 Be 反应的光束整形组件设计。束流口模拟的超热中子通量将达到1. 575× 10 9 n/s/cm 2。利用ParmteqM (V3.05)和Toutatis进行2.5 MeV BNCT RFQ的束流动力学设计、仿真和基准测试，20 mA时传输效率高于99.6%。为了简化 CW RFQ 操作中的热管理，我们采用了适度的叶片间电压设计 (U= 65 kV)，但这确实增加了加速器长度（达到 5.2 m）。使用成熟的 3D 电磁代码、CST MWS 和 ANSYS HFSS，我们能够处理 BNCT RFQ 的复杂性，同时考虑 RF 体积中每个组件的贡献。这使我们能够优化全长模型中的纵向场分布。此外，参数化建模技术对于广泛的修改和模拟也大有裨益。此外，还研究了该RFQ的谐振频率调谐，得出叶片通道和壁通道的调谐灵敏度分别为- 16.3 kHz/°C和12.4 kHz/°C。最后，研究了该RFQ的倍频电平和同轴耦合器中的倍频抑制。
Abstract Boron Neutron Capture Therapy (BNCT) promises a bright future in cancer therapy for its highly selective destruction of cancer cells, using the 10 B+ n→ 7 Li+ 4 He reaction. It offers a more satisfactory therapeutic effect than traditional methods for the treatment of malignant brain tumors, head and neck cancer, melanoma, liver cancer and so on. A CW 4-vane RFQ, operating at 162.5 MHz, provides acceleration of a 20 mA proton beam to 2.5 MeV, bombarding a liquid lithium target for neutron production with a soft neutron energy spectrum. The fast neutron yield is about 1.73× 10 13 n∕ s. We preliminarily develop and optimize a beam shaping assembly design for the 7 Li (p, n) 7 Be reaction with a 2.5 MeV proton beam. The epithermal neutron flux simulated at the beam port will reach up to 1. 575× 10 9 n/s/cm 2. The beam dynamics design, simulation and benchmark for 2.5 MeV BNCT RFQ have been performed with both ParmteqM (V3. 05) and Toutatis, with a transmission efficiency higher than 99.6% at 20 mA. To ease the thermal management in the CW RFQ operation, we adopt a modest inter-vane voltage design (U= 65 kV), though this does increase the accelerator length (reaching 5.2 m). Using the well-developed 3D electromagnetic codes, CST MWS and ANSYS HFSS, we are able to deal with the complexity of the BNCT RFQ, taking the contribution of each component in the RF volume into consideration. This allows us to optimize the longitudinal field distribution in a full-length model. Also, the parametric modeling technique is of great benefit to extensive modifications and simulations. In addition, the resonant frequency tuning of this RFQ is studied, giving the tuning sensitivities of vane channel and wall channel as− 16.3 kHz/° C and 12.4 kHz/° C, respectively. Finally, both the multipacting level of this RFQ and multipacting suppressing in the coaxial coupler are investigated.