重离子治癌装置研究

介绍了重离子治癌装置的最新发展状况 ,比较了两类典型的旋转机架的结构及光学特性 ,给出了离子光学的限制条件 .设计了一台桶形机架 ,为兰州重离子冷却储存环应用于医学治疗进行了预研. A simple plane rotating gantry is proposed at the Heavy Ion Research Facility in Lanzhou (HIRFL), where a new project named Cooling Storage Ring is under construction. The gantry is 18 metre long, 5 metre high from upper beam axes to rotation axes. It consists of eight quadruples, two 45° and one large aperture 90° dipole magnets. It is equipped with a two direction magnetic raster scanning system. A beam spot of radii between 2 to 5 mm can be achieved at∶...     

CSR切割磁铁设计

兰州重离子加速器冷却储存环(HIRFL CSR)由一个主环(CSRm)和实验环(CSRe)构成.两个储存环的束流注入与引出都需要借助于切割磁铁的导向来完成.介绍了CSR的切割磁铁的物理设计和二维场计算. In order to satisfy the requirement of beam injection and extraction of CSR, four magnetic septums will be used in the accelerator. In the design, the shape of the lamination is optimized by 2-D magnetic field calculation. Also, in order to decrease the leakage field and obtain a satisfied field distribution, a special auxiliary coil and a shield iron plate are considered and as well as the construction of the septum leg is treated in a special way. As a result, the leakage field is almost...     

泰克频谱仪IQT文件的后台处理及在电子冷却实验中的应用

泰克实时频谱仪存储的IQT格式数据文件的特殊结构给后期实验数据处理带来不便。分析了IQT文件的存储结构,说明了泰克实时频谱仪的IQT格式数据文件的后台处理过程,通过数学方法提高了文件中频变弱信号的强度;通过对频谱仪实验数据进行数学处理,得到了兰州重离子加速器冷却储存环36Ar18+离子束的纵向电子冷却力大小随离子-电子相对速度的变化曲线。该处理方法弥补了频谱仪离线分析软件的局限性。     

兰州重离子加速器冷却储存环中电子冷却性能

为了在兰州重离子加速器冷却储存环(HIRFL-CSR)上开展一维离子束序化的研究,在CSR主环上,对6.39 MeV/u的58Ni19+离子束进行了冷却累积实验。测量了离子束与电子束之间不同的水平、垂直夹角以及不同电子束剖面的情况下,束流累积及束流寿命变化情况;重点研究了离子束衰减过程中动量分散随离子数的变化规律,拟合计算得到了动量分散随离子数按照幂函数衰减的指数;在给定离子数的情况下,动量分散随夹角、电子束剖面的依赖关系,为下一步在CSR上获得纵向一维有序化离子束的研究做准备。在实验中观测到在较大的夹角情况下,离子束出现纵向振荡和中心频率移动。     

兰州重离子加速器冷却储存环

 兰州重离子加速器冷却储存环HIRFL-CSR,是一个多用途、多功能的双冷却储存环同步加速器系统,由主环CSRm和实验环CSRe构成,并以兰州重离子级联回旋加速器HIRFL作注入器。CSR利用高频变谐波的方法,将重离子束的能量从7～25 MeV/u同步加速到２00～1 000 MeV/u,同时利用重离子储存环中空心电子束冷却技术将束流品质提高１个数量级,并通过储存环的快引出及慢引出,提供多种类的重离子束以及放射性次级束(RIBs),以开展范围更广精度更高的物理实验。该装置于2007年投入运行,已取得了重要的运行结果,如实现了剥离注入与多圈注入、空心电子束对重离子束的冷却与累积、变谐波宽能区同步加速、等时性环型谱仪、RIBs的产生收集与ToF高分辨质量测量以及高能重离子束的变能慢引出等。     

HIRFL-SFC采用平顶波加速的模拟研究

近代物理研究所针对改善兰州重离子加速装置注入器（HIRFL-SFC）引出束流的品质,将主要考虑改进高频系统以提高Dee盒的加速电压、增加一个相位狭缝和采用平顶波加速等。其中采用平顶波加速可以有效地减小扇形聚焦回旋加速器(SFC)引出束流的能散并且提高其自身的传输效率。采用回旋加速器束流模拟程序AGORA对SFC进行模拟计算,并比较有无平顶波加速系统下束流品质的变化。结果表明,采用平顶波加速后,SFC的引出束流能散明显减小,而且在引出偏转板入口处束流的径向尺寸及圈间距满足单圈引出的条件。     

氢的制备、储存、安全检测与生物燃料电池研究

目前，化石能源日益枯竭和二氧化碳排放导致的温室效应引起了世界各国的高度关注。约五分之一的二氧化碳是由使用化石燃料的交通工具所导致的。氢能是人类至今为止已知的、最为理想的清洁能源，使用零排放的氢燃料电池驱动交通工具是减少二氧化碳排放的有效手段之一。世界各国把氢能作为战略能源进行研究，我国既是能源短缺国，又是能源消耗最大的国家之一。《国家中长期科学和技术发展规划纲要》明确指出，能源是未来15年我国科技发展的重要领域，清洁能源低成本规模化开发利用则是重点领域和优先主题。 本文将将简要介绍课题组在铝基材料制氢技术、多孔金属有机框架化合物（MOFs）材料储氢技术、基于石英微天平的氢气安全检测技术和生物燃料电池的有关研究工作。     

核壳复合材料NH2-MIL-125@TPA-COF用于高效液相色谱分离位置异构体

该文通过在金属－有机骨架材料（MOF）NH2－MIL－125表面原位生长共价有机骨架材料（COF）TPA－COF,制备了核壳复合材料（MOF@COF）NH2－MIL－125@TPA－COF,采用X-射线粉末衍射（PXRD）、红外光谱（FTIR）和扫描电镜（SEM）等手段对该复合材料进行表征,并将其作为固定相成功制备了NH2－MIL－125@TPA－COF色谱填充柱（25 cm long × 2.1 mm i.d.）。在正相（正己烷－异丙醇（9∶1））、反相（甲醇－水（9∶1））高效液相色谱（HPLC）条件下,考察了该柱对一系列位置异构体的分离性能。结果表明,该柱在较低的背景压力（60～100 kPa）下对9种位置异构体（溴硝基苯、硝基苯胺、氯苯酚、二硝基苯、碘苯胺、溴苯胺、苯二胺、甲苯胺和氯苯胺）表现出较好的分离能力,其中溴硝基苯、硝基苯胺和二硝基苯能达到基线分离,且最大分离度（Rs）为9.71。在反相HPLC条件下,邻-溴硝基苯、间-硝基苯胺和邻-氯苯酚的柱效分别为18 424、19 053、12 954 plates·m－1。以溴硝基苯为分析物,在正相HPLC条件下,考察了该柱的重现性和稳定性。该柱通过5次重复进样（第50次、第100次、第150次、第200次、第250次）,溴硝基苯保留时间和峰面积的相对标准偏差（RSD）分别为0.29%和0.89%,表明所制备的色谱柱具有较好的重现性和稳定性。核壳复合材料NH2－MIL－125@TPA－COF作为一种新型的HPLC固定相用于位置异构体分离具有良好的应用前景。     

Absolute dielectronic recombination rate coefficients of highly charged ions at the storage ring CSRm and CSRe

Dielectronic recombination(DR) is one of the dominant electron–ion recombination mechanisms for most highly charged ions(HCIs) in cosmic plasmas, and thus, it determines the charge state distribution and ionization balance therein.To reliably interpret spectra from cosmic sources and model the astrophysical plasmas, precise DR rate coefficients are required to build up an accurate understanding of the ionization balance of the sources. The main cooler storage ring(CSRm) and the experimental cool...     

Enhancement of electron–ion recombination rates at low energy range in the heavy ion storage ring CSRm

Recombination of Ar¹⁴⁺, Ar¹⁵⁺, Ca¹⁶⁺, and Ni¹⁹⁺ ions with electrons has been investigated at low energy range based on the merged-beam method at the main cooler storage ring CSRm in the Institute of Modern Physics, Lanzhou,China. For each ion, the absolute recombination rate coefficients have been measured with electron–ion collision energies from 0 meV to 1000 meV which include the radiative recombination(RR) and also dielectronic recombination(DR)processes. In order to interpret the measured results, RR cross sections were obtained from a modified version of the semiclassical Bethe and Salpeter formula for hydrogenic ions. DR cross sections were calculated by a relativistic configuration interaction method using the flexible atomic code(FAC) and AUTOSTRUCTURE code in this energy range. The calculated RR + DR rate coefficients show a good agreement with the measured value at the collision energy above 100 meV.However, large discrepancies have been found at low energy range especially below 10 meV, and the experimental results show a strong enhancement relative to the theoretical RR rate coefficients. For the electron–ion collision energy below 1 meV, it was found that the experimentally observed recombination rates are higher than the theoretically predicted and fitted rates by a factor of 1.5 to 3.9. The strong dependence of RR rate coefficient enhancement on the charge state of the ions has been found with the scaling rule of q^3.0, reproducing the low-energy recombination enhancement effects found in other previous experiments.