ATPF–a dedicated proton therapy facility

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 method, the extraction energy can be as many as about 200 between 60 MeV and 230 MeV. A new method – 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.     

Physical design of scanning gantry for proton therapy facility

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.     

Irradiation methods and nozzle design for the advanced proton therapy facility

A conception design of the Advanced Proton Therapy Facility （APTF） has been carried out. The system intentionally employs a slow-cycling synchrotron with a maximum energy of 250 MeV, two rotating gantries and two fixed beam nozzles for the treatment. In this paper, we try to compare the strength and weaknesses between the two treatment methods： the beam spreading and the pencil beam scanning. The application of the pencil beam scanning method and the double-scattering method together with the related nozzle design at APTF is also given. The simulation results of employing the double-scattering method have been given during the preliminary design.     

New linear accelerator （Linac） design based on C-band accelerating structures for SXFEL facility

A C-band accelerator structure is one promising technique for a compact XFEL facility. It is also attractive in beam dynamics in maintaining a high quality electron beam, which is an important factor in the performance of a free electron laser. In this paper, a comparison between traditional S-band and C-band accelerating structures is made based on the linac configuration of a Shanghai Soft X-ray Free Electron Laser (SXFEL) facility. Throughout the comprehensive simulation, we conclude that the C-band structure is much more competitive.     

重离子治疗的物理与生物性能和装置原理

 半个世纪来,放射治疗界一直在寻找一种物理剂量分布良好和生物(物理)效应也好的放射线和粒子。几十年来的临床治疗实践,证实了常用的X射线和电子射线的物理剂量分布和生物(物理)效应都不理想。中子和负π粒子的生物效应虽好,但是物理剂量分布不好,给正常组织带来太大的损害。当前较先进的质子治疗,固有的布拉格峰物理特性能使剂量分布很好,但其生物(物理)效应仅稍高于X射线和电子,对治疗抗阻型和乏氧型的肿瘤细胞还难以奏效。而重离子治疗的物理剂量分布和生物(物理)效应都很理想,因此人们转向研究重离子治疗的可能性。     

BEPC de前前后后

 80年代是我国高能物理事业的一个转折点.BEPC按计划高质量地完成,为我国高能物理实验研究提供了一个极其重要的手段;也表明我国的加速器事业已在世界高技术领域中占有了一席之地.BEPC的成就凝聚着几代人的心血.早在1957年,在王淦昌教授的领导下。选派了一批年青的科学家,赴苏学习高能加速器的设计及建造.一年后,在苏联专家的指导下,进行1-2GeV电子同步加速器的设计,这一设计在1958年的大跃进中被认为是保守落后的,而把方案改成15GeV的质子同步加速器.     

高效率生产粲粒子的工厂——BEPCⅡ加速器巡礼

1974年11月,丁肇中和里克特几乎同时宣布,他们的实验组各自在美国布鲁克海文实验室的质子同步加速器AGS和斯坦福直线加速器中心的正负电子对撞机SPEAR上,发现了一个能量约为31亿电子伏特的新粒子,并分别命名为J粒子和Ψ粒子,后来统一称为J／Ψ粒子。这一被誉为“十一月革命”的发现,使高能物理的研究迈进了一个新的境界。     

能量放大器——加速器驱动反应堆获得干净核能的新思路

 不久前,西欧核子中心主任、诺贝尔奖金获得者鲁比亚（C.Rubbia）领导的一个小组从高能物理实验中常用的量能器概念出发,提出了一个提供干净核能的新概念:利用高能强流质子加速器（能量0.8-1.5GeV,平均流强～7mA）产生的高能质子束,在物质中形成核级联过程而产生大量的中子,天然钍(²³²Th)俘获中子而转变为裂变元素²³³U,²³³U又裂变产生中子维持链式反应,他们将这个装置称为能量放大器,装置启动后,裂变元素在天然钍中的比例很快可以达到相对稳定,形成一个长期稳定的能量产出,装置运行于次临界状态和相当低的中子通量下(～10¹⁴cm^-2·s^-1)以确保增值过程的稳定持续和设备无临界危险。     

Transverse Momentum and Rapidity Distributions of Φ Mesons Produced in Pb-Pb Collisions at SPS Energies

To investigate the excitation degree of the interacting system and the penetrating power of the projectile nucleus and to understand their dependences on incident energy, the transverse momentum and rapidity distributions of particles produced in nucleus-nucleus collisions at high energies are studied by using a multisource ideal gas model. The calculated results are compared with the most recent NA49 experimental data of φ mesons produced in Pb-Pb collisions at the Super Proton Synchrotron （SPS） energies.     

RFQ的束流动力学设计研究

本文评述了RFQ直线加速器对于加速低β粒子的重要优越性。给出了它的近轴区内高频电场的分布及粒子运动方程。叙述了束流的俘获效率及纵向相空间分布对于RFQ参数及注入能量的依赖关系。给出了750keV质子RFQ加速器的动力学设计研究。     

Irradiation methods and nozzle design for the advanced proton therapy facility

A conception design of the Advanced Proton Therapy Facility (APTF) has been carried out. The system intentionally employs a slow-cycling synchrotron with a maximum energy of 250 MeV, two rotating gantries and two fixed beam nozzles for the treatment. In this paper, we try to compare the strength and weaknesses between the two treatment methods: the beam spreading and the pencil beam scanning. The application of the pencil beam scanning method and the double-scattering method together with the related nozzle design at APTF is also given. The simulation results of employing the double-scattering method have been given during the preliminary design.     

Physical design of scanning gantry for proton therapy facility

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.     

质子治疗装置动态电源控制系统研发

针对质子治疗装置中主环动态电源多平台能量的引出需求,研制了基于开源平台的高速实时动态电源控制系统,该控制系统以开源平台Beaglebone作为顶层硬件接口,以现场可编程逻辑门阵列（FPGA）为核心的控制器作为底层硬件接口,采用分布式的实验物理及工业控制系统（EPICS）进行远程控制。该系统可实时传输任意动态电源的输出参考电流波形数据,并结合定时系统与联锁系统,控制动态电源按预设电流波形进行输出,并实现多平台能量的引出。实验结果显示该控制系统能实现每秒最高十万条指令传输,百万次数据传输零误码率。同时,该系统结构灵活、扩展性强,可作为通用控制平台。     

Individual patient shielding for a proton eye therapy facility

The first proton ocular radiotherapy facility in Poland has been developed at the Institute of Nuclear Physics (IFJ PAN), Kraków, in collaboration with the Clinic of Ophthalmology and Ocular Oncology of the Collegium Medicum of the Jagiellonian University in Kraków and the Centre of Oncology of the Maria Sk?odowska–Curie Memorial Institute Kraków Branch. For the proton beam from the AIC-144 isochronous cyclotron the unwanted patient dose due to secondary radiation - predominantly neutrons - has been evaluated using the MCNPX code. Optimisation of the beam forming elements and designing of the additional patient shielding has been performed to minimize the unwanted patient’s dose.     

A simulation study of a dual-plate in-room PET system for dose verification in carbon ion therapy

During carbon ion therapy,lots of positron emitters such as11C,15O,10C are generated in irradiated tissues by nuclear reactions,and can be used to track the carbon beam in the tissue by a positron emission tomography(PET)scanner.In this study,an dual-plate in-room PET scanner has been designed and evaluated based on the GATE simulation platform to monitor patient dose in carbon ion therapy.The dual-plate PET is designed to avoid interference with the carbon beamline and with patient positioning.Its performance was compared with that of four-head and full-ring PET scanners.The dual-plate,four-head and full-ring PET scanners consisted of 30,60,60detector modules,respectively,with a 36 cm distance between directly opposite detector modules for dose deposition measurements.Each detector module consisted of a 24×24 array of 2 mm×2 mm×18 mm LYSO pixels coupled to a Hamamatsu H8500 PMT.To estimate the production yield of positron emitters,a 10 cm×15 cm×15 cm cuboid PMMA phantom was irradiated with 172,200,250 MeV/u12C beams.3D images of the activity distribution measured by the three types of scanner are produced by an iterative reconstruction algorithm.By comparing the longitudinal profile of positron emitters along the carbon beam path,it is indicated that use of the dual-plate PET scanner is feasible for monitoring the dose distribution in carbon ion therapy.     

A simulation study of a dual-plate in-room PET system for dose verification in carbon ion therapy

During carbon ion therapy, lots of positron emitters such as 11C, 15O, 11C are generated in irradiated tissues by nuclear reactions, and can be used to track the carbon beam in the tissue by a positron emission tomography （PET） scanner. In this study, an dual-plate in-room PET scanner has been designed and evaluated based on the GATE simulation platform to monitor patient dose in carbon ion therapy. The dual-plate PET is designed to avoid interference with the carbon beamline and with patient positioning. Its performance was compared with that of four-head and full-ring PET scanners. The dual-plate, four-head and full-ring PET scanners consisted of 30, 60, 60 detector modules, respectively, with a 36 cm distance measurements. Each detector module consisted of a between directly opposite detector modules for dose deposition 24~24 array of 2 mm×2 mm×18 mm LYSO pixels coupled to a Hamamatsu H8500 PMT. To estimate the production yield of positron emitters, a 10 cm×15 cm×15 cm cuboid PMMA phantom was irradiated with 172, 200, 250 MeV/u 12C beams. 3D images of the activity distribution measured by the three types of scanner are produced by an iterative reconstruction algorithm. By comparing the longitudinal profile of positron emitters along the carbon beam path, it is indicated that use of the dual-plate PET scanner is feasible for monitoring the dose distribution in carbon ion therapy.     

质子辐照铝膜反射镜的慢正电子湮没研究

采用分光光度计测定了60keV质子辐照后铝膜反射镜反射光谱的变化规律.用慢正电子湮没等分析技术研究了辐照损伤的微观机制.结果表明，当质子辐照主要作用于反射镜铝膜层中时反射镜在200—800nm波长范围内反射率随辐照剂量增加而下降.入射质子可对铝膜中的缺陷产生填充作用，减小铝膜中电子密度，增加弱束缚电子带间跃迁.紫外至可见光能量较高的波段可引起带间激发跃迁，使相应的谱段反射率下降，导致反射镜光学性能的退化. 关键词： 反射镜 光学性能 质子辐照 慢正电子湮没