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VACUUM SIMULATIONS FOR HEAVY ION BEAMS IN THE AGOR CYCLOTRON
No full textThe TRIμP program at the KVI requires the
development of high intensity heavy ion beams in
particular 206Pb27+ at 8.5 MeV/amu and 20Ne6+ at 23.3
MeV/amu. For the Pb beam, losses in the cyclotron are
one of the factors limiting the intensity that can be
achieved. Charge changing collisions between the
heavy ion beam and the residual gas cause subsequent
desorption off the walls of the cyclotron which in turn
leads to vacuum degradation. This causes a positive
feedback loop leading to a reduced transmission with
increasing beam intensity. We have developed a model
to track the trajectory of the particles after a charge
changing collision and 3D vacuum simulations to
predict pressure profiles from desorption values. We
have built and tested an experimental setup to measure
beam induced desorption for relevant materials.
Preliminary results are described.IMP;Chinese Academy of Science
APPLICATION OF HTS WIRE TO MAGNETS
No full textWe have been developing mgnets utilizing hightemperature
superconducting (HTS) wire. A scanning
magnet was designed, fabricated, and tested for its
suitability as beam scanner. After successful cooling tests,
the magnet performance was studied using DC and AC
currents. In AC mode, the magnet was operated at
frequencies of 30-59Hz and a temperature of 77K as well
as 10-20Hz and 20K. The power loss dissipated in the
coils was measured and compared with the model
calculations. The observed loss per cycle was independent
of the frequency and the scaling law of the excitation
current was consistent with theoretical predictions for
hysteretic losses in HTS wires. As the next step, a 3T
dipole magnet is under construction now.IMP;Chinese Academy of Science
DESIGN OF HIGH ENERGY HADRON FFAGS FOR ADSR AND OTHER APPLICATIONS
No full textDesign study of high energy proton FFAG accelerator
has been carried out at Kyoto University Research Reactor
(KURRI) for the next generation ADSR experiment where
the proton beam energy covers up to 700MeV. The scaling
type of FFAG with spiral sectors was employed. Details of
the design issue concerning about the operational working
points, lattice parameters and 3D magnet modeling / optimization
are described. Also, some possibilities to apply
this design to carbon therapy accelerators are presented.IMP;Chinese Academy of Science
Development of Mini Coincidence Imaging Detection System And its Application Research
No full text随着中科院近代物理研究所重离子束治癌技术和浅层治疗应用基础研究的不断开展，对束流入射深度分布的影像测试研究成为了重要的研究课题。本论文基于此背景，成功研制了小型符合影像探测系统，并进行了深入的影像测试应用研究。符合影像探测的基本原理为通过符合探测系统对正电子放射性核素引起的正负电子湮灭辐射进行符合测量，并利用相应的影像重建方法就可以得到影像体的影像结果。研制的符合影像探测系统由两个探测单元组成，单元的核心探测器件为具有64个通道的位置灵敏平板型光电倍增管H8500，其前端与性能优良的BGO闪烁晶体阵列耦合，输出信号采用电阻网络简化读出。通过比较蒙特卡罗模拟结果和实际测试结果，优化设计了符合探测单元，主要确定了闪烁晶体单元的大小和组成阵列的构形：探测阵列由19X19块晶体单元组成，每块晶体单元大小为2X2X10mm3，间距为0.3mm的Tefon薄膜隔离。基于这种单元构形，探测单元的本征位置分辨约为：1.37mm(FWHM)，组成的符合影像探测系统空间位置分辨约为（对22Na源）：1.87mm(FWHM)。上述指标接近于小型符合探测系统最佳本征和空间位置分辨。符合影像探测系统分别在22Na 正电子发射源和12C束流入射有机靶不同条件下进行测试研究。采用中心焦平面影像原理进行数据的影像重建，得到了符合探测系统的空间位置分辨能力、最大计数率和靶内深度分布的影像测试结果。分析束流入射PMMA靶60秒后的测量数据，成功分离了靶内10C、11C 和15O 三种主要正电子放射性核素产物，对不同产物的深度分布与测试布拉格峰位进行了比较，得到了一种如何实现浅层治疗在线监测的研究方法。实验研究结果表明，研制的这一套2D符合影像探测系统具有高的空间位置分辨率、较大的探测视野(约50X50mm3)和较好的影像能力。12C束流入射有机靶的影像测试研究结果表明，该方法和该探测系统可以应用于重离子浅层治疗，可以在治疗过程中实现快速地、准确地对布拉格峰位进行监测随着中科院近代物理研究所重离子束治癌技术和浅层治疗应用基础研究的不断开展，对束流入射深度分布的影像测试研究成为了重要的研究课题。本论文基于此背景，成功研制了小型符合影像探测系统，并进行了深入的影像测试应用研究。符合影像探测的基本原理为通过符合探测系统对正电子放射性核素引起的正负电子湮灭辐射进行符合测量，并利用相应的影像重建方法就可以得到影像体的影像结果。研制的符合影像探测系统由两个探测单元组成，单元的核心探测器件为具有64个通道的位置灵敏平板型光电倍增管H8500，其前端与性能优良的BGO闪烁晶体阵列耦合，输出信号采用电阻网络简化读出。通过比较蒙特卡罗模拟结果和实际测试结果，优化设计了符合探测单元，主要确定了闪烁晶体单元的大小和组成阵列的构形：探测阵列由19X19块晶体单元组成，每块晶体单元大小为2X2X10mm3，间距为0.3mm的Tefon薄膜隔离。基于这种单元构形，探测单元的本征位置分辨约为：1.37mm(FWHM)，组成的符合影像探测系统空间位置分辨约为（对22Na源）：1.87mm(FWHM)。上述指标接近于小型符合探测系统最佳本征和空间位置分辨。符合影像探测系统分别在22Na 正电子发射源和12C束流入射有机靶不同条件下进行测试研究。采用中心焦平面影像原理进行数据的影像重建，得到了符合探测系统的空间位置分辨能力、最大计数率和靶内深度分布的影像测试结果。分析束流入射PMMA靶60秒后的测量数据，成功分离了靶内10C、11C 和15O 三种主要正电子放射性核素产物，对不同产物的深度分布与测试布拉格峰位进行了比较，得到了一种如何实现浅层治疗在线监测的研究方法。实验研究结果表明，研制的这一套2D符合影像探测系统具有高的空间位置分辨率、较大的探测视野(约50X50mm3)和较好的影像能力。12C束流入射有机靶的影像测试研究结果表明，该方法和该探测系统可以应用于重离子浅层治疗，可以在治疗过程中实现快速地、准确地对布拉格峰位进行监
Preparation of Microporous Membranes by Swift Heavy Ion Irradiation and Impedance Characterization
No full textPolypropylene (PP) microporous membranes were successfully prepared by swift heavy ion irradiation and track-etching. Polypropylene foils were irradiated with Au-197 ions of kinetic energy 11.4 MeV.u(-1) (total energy of 2245.8 MeV) and fluence 1x10(8) ions.cm(-2) at normal incidence. The damaged regions produced by the gold ions along the trajectories were etched in H2SO4 and K2Cr2O7 solutions leading to the formation of cylindrical pores in the membranes. The pore diameters of the PP microporous membranes increased from 380 to 1610 nm as the etching time increased from 5 to 30 min. The surface and cross-section morphologies of the porous membranes were characterized by scanning electron microscopy (SEM). The micropores in the membranes were found to be cylindrical in shape, homogeneous in distribution, and equal in size. Some mathematical relations of the porosity of the PP microporous membranes were established by analytic derivation. The microporous membranes were used in lithium-ion batteries to measure their properties as separators. The electrical conductivity of the porous membrane immersed in liquid electrolyte was found to be comparable to that of commercial separators by electrochemical impedance spectroscopy (EIS). The results showed that the porosity and electrical conductivity were dependent on the ion fluence and etching time. By adjusting these two factors, microporous membranes with good porosity and electrical conductivity were made that met the requirements for commercial use
用于粒子探测器的CMOS FET采样保持电路的设计与仿真(英文)；Design and Simulation of Track/Hold Circuit with CMOS FET for Particle Detector
No full text介绍了一个峰保持电路。该电路适用于silicon strip,Si(Li),CdZn Te and CsI等探测器,实现采样-保持功能。已成功进行了基于CMOSFET的采样-保持电路的设计和仿真,通过使用Proteus的PSPICE仿真器和BSIMV3.3模型参数完成了电路性能的仿真。同时,实现了采样时间可在60ns到4.44s范围内进行选择,该电路具有较好的线性
用于辐射复合与双电子复合实验的低能离子闪烁探测器；A Scintillator Detector for Low Energy Projectile Detection in Radiative Recombination and Dielectron Recombination Experiments
No full text为了在CSRm的电子冷却器上进行辐射复合以及双电子复合实验,需要探测能量小于4MeV/u的离子,因此设计了新的置于超高真空环境的CsI(Tl)闪烁探测器,探测器采用的光电倍增管为R7525(Hamamatsu)。介绍了新闪烁探测器的结构,并对其进行了性能测试。测试结果表明,该探测器对高、低能离子均有良好的响应,探测器的信号十分明显。探测器的最高计数率可以达到106ions/s,并且探测器附近的真空度可达10-10Pa量级,能够满足辐射复合与双电子复合实验以及储存环对真空的要求,为今后在CSRm上进行复合实验打下了良好的基础
两种保护剂对C离子诱导小鼠急性肝损伤的应答；Response of Two Protective Agents to Acute Injury Induced by ~(12)C~(6+) Ions in Mouse Liver
No full text比较了N-乙酰半胱氨酸(NAC)及乙酰左旋肉毒碱(ALCAR)对12C6+离子照射小鼠的损伤效应,并探讨了其可能的作用机制。利用4Gy剂量的12C6+离子束对预先给予NAC(100mg/kg)和ALCAR(100mg/kg)保护的昆明小鼠进行单次全身照射。随后检测肝组织中总抗氧化能力(TAC)、DNA单链断裂和细胞凋亡率。结果显示,与照射对照组相比,提前给予NAC和ALCAR均极显著地增强了肝组织的抗氧化能力(P<0.001),减轻了12C6+离子导致的肝组织中DNA断裂(P<0.001)和细胞凋亡(P<0.001)。此外,还发现ALCAR组抗重离子辐照损伤的能力显著地高于NAC组(P<0.05)。实验结果提示了NAC和ALCAR可通过抵御组织内的氧化胁迫,阻止DNA链的断裂和细胞的凋亡,实现对C离子辐照损伤的保护效应。而且ALCAR比NAC可能更适合成为有潜力、有希望的抗C重离子辐射药物
基于激光诱导击穿光谱技术的铝合金成分定量分析；Quantitative analysis of element concentration in Al alloy by using laser-induced breakdown spectroscopy
No full text利用Nd:YAG激光器输出的532nm激光束对位于空气中的标准变形铝合金样品进行烧蚀产生了激光诱导等离子体.对测量的230—440nm波长范围的光谱进行了谱线标定,同时基于自由定标方法对样品成分进行了定量分析,确定了样品中的元素含量.分析结果与标准值具有较好的一致性
基于JUPITER的uClinux移植及其应用实例；uClinux Porting Based on JUPITER and example of Application
No full text介绍了嵌入式处理器JUPITER,详细分析了uClinux嵌入式操作系统的特点。给出了基于JUPITER和uClinux的嵌入式网关。通过嵌入式网关实例详细说明了在JUPITER上的移植uClinux的方法,以及uClinux下应用程序的开发