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医用偏转磁聚焦结构的重离子或质子同步加速器
No full text本实用新型涉及医用带电粒子同步加速器磁聚焦结构的设计方法技术领域，尤其是涉及一种医用45°偏转磁聚焦结构的重离子或质子同步加速器。包括有八个偏转二极铁和八个同步加速器直线段，所述的八个偏转二极铁和八个同步加速器直线段依次通过环形真空管道交替连接，所述的八个偏转二极铁均为45°偏转二极铁。采用45°偏转磁聚焦结构包括一个带电粒子运行在其中的环形真空管道，以及布置在环形管道上的磁铁元件、加速元件、注入引出元件。有效的利用同步加速器空间，安装尽可能少的元件实现医用重离子/质子医用同步加速器功能，最大程度的降低制造成本和安装空间，提高治疗效率，降低治疗成本
ACTIVITIES AT THE COSY/JÜLICH INJECTOR CYCLOTRON JULIC
No full textThe operation and development of the accelerator<br />facility COSY is based upon the availability and<br />performance of the isochronous cyclotron JULIC as the<br />pre-accelerator. The cyclotron has been commissioned in<br />1968 and exceeded 241 000 hours of operation. In parallel<br />to the operation of COSY the cyclotron beam is also used<br />for irradiation and nuclide production. A brief overview of<br />activities, performance, new and improved installations<br />und procedures is presented
Thermal analysis of DTL in the SSC-LINAC
No full textA linear accelerator as a new injector for the Separated Sector Cyclotron at the Heavy Ion Research Facility of LAN Zhou is being designed. The Drift-Tube-Linac (DTL) has been designed to accelerate (238)U(34+) from 0.140 MeV/u to 0.97 MeV/u [1]. The 3D finite element analysis of thermal behavior is presented in this paper. During operation, the cavity will produce Joule heat. The cavity will not work normally due to the high temperature and thermal deformation will lead to frequency drift. So it is necessary to perform thermal analysis to ensure the correct working temperature is used. The result of the analysis shows that after the water cooling system is put into the cavity the temperature rise is about 20 degrees and the frequency drift is about 0.15%
Neutron spectroscopic factors of Ar-34 and Ar-46 from (p,d) transfer reactions
No full textSingle-neutron-transfer measurements using (p,d) reactions have been performed at 33 MeV per nucleon with proton-rich Ar-34 and neutron-rich Ar-46 beams in inverse kinematics. The extracted spectroscopic factors are compared to the large-basis shell-model calculations. Relatively weak quenching of the spectroscopic factors is observed between Ar-34 and Ar-46. The experimental results suggest that neutron correlations have a weak dependence on the asymmetry of the nucleus over this isotopic region. The present results are consistent with the systematics established from extensive studies of spectroscopic factors and dispersive optical-model analyses of Ca40-49 isotopes. They are, however, inconsistent with the trends obtained in knockout-reaction measurements
Excitation and dissociation of tungsten hexacarbonyl W(CO)(6): Statistical and nonstatistical dissociation processes
No full textWe have studied the excitation and dissociation processes of the molecule W(CO)(6) in collisions with low kinetic energy (3 keV) protons, monocharged fluorine, and chlorine ions using double charge transfer spectroscopy. By analyzing the kinetic energy loss of the projectile anions, we measured the excitation energy distribution of the produced transient dications W(CO)(6)(2+). By coincidence measurements between the anions and the stable or fragments of W(CO)(6)(2+), we determined the energy distribution for each dissociation channel. Based on the experimental data, the emission of the first CO was tentatively attributed to a nonstatistical direct dissociation process and the emission of the second or more CO ligands was attributed to the statistical dissociation processes. The dissociation energies for the successive breaking of the W-CO bond were estimated using a cascade model. The ratio between charge separation and evaporation (by the loss of CO+ and CO, respectively) channels was estimated to be 6% in the case of Cl+ impact. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3523347
Annealing ambient on the evolution of He-induced voids in silicon
No full textThe effects of annealing ambient on the He-induced voids in silicon were investigated using the combination of the Doppler broadening spectroscopy using a variable-energy positron beam and cross-section transmission electron microscopy (XTEM). A < 1 0 0 >-oriented silicon wafer was implanted with He ions at an energy of 15 keV to a dose of 2 x 10(16) cm(-2) at room temperature. Post-implantation, the samples were annealed at a temperature of 1000 degrees C in the ambient of vacuum, argon, nitrogen, air and oxygen. Positron annihilation spectroscopy (PAS) spectra varied with the annealing ambient. XTEM micrographs demonstrated that the density of He-induced voids could be influenced by the annealing ambient. (C) 2011 Elsevier B.V. All rights reserved
氮化镓异质结高能电子辐照的电子背散射衍射研究
No full text<span id="ChDivSummary" name="ChDivSummary">利用2MeV电子辐照氮化镓(GaN)异质结,辐照剂量分别为1×1015/cm2和5×1015/cm2。电子背散射衍射(EBSD)菊池图的图像质量IQ值随辐照剂量的增加而增大,对应的表层应变或畸变减小。扫描电镜能谱(SEM/EDS)分析发现氧原子在外延层心部发生富集,表明高能电子辐照在GaN外延层内引入晶格损伤。表层应变状态的改变与杂质扩散和辐照点缺陷的引入直接相关,其中晶格损伤是影响表面应变状态的主要因素。 </span><a id="ChDivSummaryMore" style="DISPLAY: none">更多</a>国家自然科学基金资助项目(No.50872013,No.10575124,No.10979063
电子辐照改性聚合物电解质的制备及其在染料敏化太阳电池中的应用
No full text<p><font face="宋体" size="3">发明提供了一种电子辐照改性聚合物电解质的制备及其在染料敏化纳米晶太阳电池上应用，属于太阳能电池技术领域和电子加速技术领。本发明以环氧乙烷与聚丙烯腈为原料，以碘和碘化钾的混合物为氧化还原电对，加入到乙腈与二甲基甲酰胺的混合液中，于70～80℃温度下搅拌混合均匀形成凝胶态物质，再对凝胶态物质进行电子辐照改性，得到改性的聚合物电解质。经测定，改性的聚合物电解质的离子传导率从10-4量级提高到10-2量级s.cm-1，应用在染料敏化纳米晶太阳电池上，可使太阳电池的在标准光源下的效率提高了30～50％。</font></p
