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北京散裂中子源RCS注入系统物理设计和研究 总被引:4,自引:0,他引:4
北京散裂中子源(BSNS)的主加速器——快循环同步加速器(RCS)采用H-剥离注入方法, 将从直线加速器预加速的束流进行累积和进一步加速. 束流损失率的控制是该类高功率质子加速器所面临的关键问题之一, 而束流损失中很重要的部分是由空间电荷效应造成的. 为了减小该类束流损失, 注入系统设计中利用H-剥离注入和相空间涂抹方法将直线加速器预加速的发射度较小的束流尽可能均匀地涂抹到较大的横向相空间中. 与其他的类似加速器相比, RCS注入系统将所有注入元件放在一个长为9m的无色散漂移节中以充分节省RCS环的纵向空间, 并使对注入系统的操作与对RCS主体的操作完全独立. 对于RCS累积的粒子数1.9×1013, 空间电荷效应对粒子的运动有非常重要的作用, 本文介绍了采用ORBIT程序进行三维模拟计算并进行设计优化的结果. 还介绍了系统设计时需要考虑的其他重要因素, 如质子穿越、电子收集等. 相似文献
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The China Spallation Neutron Source (CSNS) is a large scientific facility with the main purpose of serving multidisciplinary research on material characterization using neutron scattering techniques. The accelerator system is to provide a proton beam of 120 kW with a repetition rate of 25 Hz initially (CSNSⅠ), progressively upgradeable to 240 kW (CSNS-Ⅱ) and 500 kW (CSNS-Ⅱ'). In addition to serving as a driving source for the spallation target, the proton beam can be exploited for serving additional functions both in fundamental and applied research. The expanded scientific application based on pulsed muons and fast neutrons is especially attractive in the overall consideration of CSNS upgrade options. A second target station that houses a muon-generating target and a fast-neutron-generating target in tandem, intercepting and removing a small part of the proton beam for the spallation target, is proposed. The muon and white neutron sources are operated principally in parasitic mode, leaving the main part of the beam directed to the spallation target. However, it is also possible to deliver the proton beam to the second target station in a dedicated mode for some special applications. Within the dual target configuration, the thin muon target placed upstream of the fast-neutron target will consume only about 5% of the beam traversed; the majority of the beam is used for fast-neutron production. A proton beam with a beam power of about 60 kW, an energy of 1.6 GeV and a repetition rate of 12.5 Hz will make the muon source and the white neutron source very attractive to multidisciplinary researchers. 相似文献
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ATPF—a dedicated proton therapy facility 总被引:1,自引:0,他引:1
A proton therapy facility based on a linac injector and a slow-cycling synchrotron is proposed. To obtain good treatments for different cancer types, both the spot scanning method and the double-scattering method are adopted in the facility, whereas the nozzles include both gantry and fixed beam types. The proton accelerator chain includes a synchrotron of 250 MeV in maximum energy, an injector of 7 MeV consisting of an RFQ and a DTL linac, with a repetition rate of 0.5 Hz. The slow extraction using the third-order resonance and together with the RFKO method is considered to be a good method to obtain a stable and more-or-less homogenous beam spill. To benefit the spot scanning 200 between 60 MeV and 230 MeV. A new method method, the extraction energy can be as many as about - the emittance balancing technique of using a solenoid or a quadrupole rotator is proposed to solve the problem of unequal emittance in the two transverse planes with a beam slowly extracted from a synchrotron. The facility has been designed to keep the potential to be upgraded to include the carbon therapy in the future. 相似文献
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A proton therapy facility based on a linac injector and a slow cycling synchrotron is proposed. To achieve effective treatment of cancer, a scanning gantry is required. The flexible transmission of beam and high beam position accuracy are the most basic requirements for a gantry. The designed gantry optics and scanning system are presented. Great efforts are put into studying the sensitivity of the beam position in the isocenter to the element misalignments. It shows that quadrupole shift makes the largest contribution and special attention should be paid to it. 相似文献
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The China Spallation Neutron Source (CSNS) is an accelerator-based multidisciplinary user facility to be constructed in Dongguan, Guangdong, China. The CSNS complex consists of an H- linear accelerator, a rapid cycling synchrotron accelerating the beam to 1.6 GeV, a solid-tungsten target station, and instruments for spallation neutron applications. The facility operates at 25 Hz repetition rate with an initial design beam power of 120 kW and is 相似文献
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The China Spallation Neutron Source (CSNS) is an accelerator-based facility. The accelerator of CSNS consists of a low energy linac, a Rapid Cycling Synchrotron (RCS) and two beam transport lines. The overall physics design of CSNS accelerator is described, including the design principle, the choice of the main parameters and design of each part of accelerators. The key problems of the physics design, such as beam loss and control, are also discussed. The interface between the different parts of accelerator, as well as between accelerator and target, are introduced. 相似文献
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通过阴离子聚合物聚苯乙烯磺酸钠(PSS)对碳纳米管(CNTs)进行非共价功能化修饰得到PSS功能化的碳纳米管(PSS-CNTs),利用带负电的PSS和Ce3+之间的静电作用将Ce3+组装到CNTs表面,再利用Ce3+与Pt Cl2-4之间存在的静电作用和氧化还原反应实现CeO_2和Pt纳米粒子在CNTs表面的原位沉积,得到复合催化剂Pt-CeO_2/PSS-CNTs.采用透射电子显微镜(TEM)、X射线衍射仪(XRD)、能谱仪(EDS)及拉曼光谱仪(Raman)等对催化剂进行了表征.电化学性能测试结果表明,由于PSS-CNTs表面原位沉积的Pt纳米粒子相对于在原始CNTs上沉积的Pt纳米粒子具有更小的粒径、更好的分散均匀性和稳定性,同时Pt与CeO_2之间存在良好的协同效应,Pt-CeO_2/PSS-CNTs催化剂对甲醇电催化氧化具有较好的催化活性和化学稳定性,当nPt/nCe=2/3时催化性能最优. 相似文献