Institutional Repository of Institute of Modern Physics, CAS
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Hirfl-CSR facility status and development
No full textThe HIRFL-CSR facility come into operation by the end of 2007. During operation in recent years, CSR supplied beam for experiments at several terminals and inside both CSRm and CSRe rings. The experiments covers high resolution mass measurement, cancer therapy research, neutron wall, atomic physics using electron target and internal gas target, using injection beam mainly from the SFC of cyclotron injector. New methods and further developments are required to improve the performance of CSR system including multi-gradients measurement method for beam spot commissioning and beam transfer, nonlinear effect correction and stabilization of isochronous mode of CSRe. For suppling of heverier ion beam with proper ernergy, the cyclotron complex should be enhanced and new injector is proposed to replace SFC as injector of SSC.(9 refs
双面二维硅微条探测器的沾污失效分析及修复；Contamination failure analysis and repairing for double side two dimensional silicon microstrip detectors
No full text硅微条探测器通过微电子工艺制作,易因沾污导致性能下降甚至失效;裸露的键合引线,也易因机械力形成隐性或显性失效。对上述现象的研究可用于修复、维护探测器并在设计和工艺流程中改进其性能。本文通过光学、电气手段分析其结构和制作工艺流程,根据沾污性质在不同条件下清洗探测器,中测后根据芯片图形、封装方式和电气要求修复探测器,最后采用同位素α能谱测试修复效果。对一块沾污后失效(无法加载偏压)的硅微条清洗后在大气环境,N面接地,P面加载负偏压条件下进行了测试,结果显示:170 V全耗尽,平均漏电流2.94μA,5.486 MeV的α峰能量分辨率约1.28%。失效键合所在条的另一面各条能谱观测到假峰,键合修复后消除。因沾污失效的硅微条探测器经过合适的清洗、修复,部分可以恢复性能,但清洗对表面和结构有损伤,须谨慎。另外,键合失效后,因信号不能引出导致的电荷积累会通过电容效应影响其它灵敏区。文章提示,探测器应存放于洁净,恒温,低湿度,避光,避强电磁干扰的环境,以提高能量和位置分辨率,并增加工作稳定性,延长使用寿命
束流调制器物理机制与电子学设计
No full text兰州重离子回旋加速器装置H IRFL在某种工作模式下,需要对束流在时间上进行调制,以避免束流对输运线造成损伤;并在加速器引出的束流能量较高且流强很大时,采用束流调制器可使调束在较低的流强下进行,而不必改变加速器的参数。调制器由加装在束运管道上的两个平行电极与相应的电子学电路组成。为满足调制脉冲前后沿的时间要求,电子学设计着重考虑展宽电压放大器频带低品质因数电路设计
Raman investigation of ion-implanted ZnO films
No full textZnO thin films were implanted at room temperature with 80 keV N+ or 400 keV Xe+ ions. The implantation fluences of N+ and Xe+ ranged from 5.0 x 10(14) to 1.0 x 10(17)/cm(2), and from 2.0 x 10(14) to 5.0 x 10(15)/cm(2), respectively. The samples were analyzed using Raman spectroscopy and the Raman scattering modes of the N- and Xe-ion implanted samples varying with implantation fluences were investigated. It was found that Raman peaks (bands) at 130 and 578 cm(-1) appeared in the spectra of ion-implanted ZnO samples, which are independent of the ion species, whereas a new peak at 274 cm(-1) was found only in N-ion implanted samples, and Raman band at 470 cm(-1) was found clearly in Xe-ion implanted samples. The relative intensity (peak area) increased with the increasing of the implantation fluences. From the comparison of the Raman spectra of N- and Xe-ion implanted ZnO samples and considering the damage induced by the ions, we analyzed the origin of the observed new Raman peaks (bands) and discussed the structure changes of ZnO films induced by N- and Xe-ion implantations
离子注入ZnO薄膜的拉曼光谱研究；Raman investigation of ion-implanted ZnO films
No full text室温下,用80keVN+和400keVXe+离子注入ZnO薄膜,注入剂量分别为5.0×1014—1.0×1017/cm2和2.0×1014—5.0×1015/cm2.利用拉曼散射技术对注入前后的ZnO薄膜进行光谱测量和分析,研究了样品的拉曼光谱随离子注入剂量的变化规律.实验结果发现,未进行离子注入的样品在99,435cm-1处出现两个ZnO六方纤锌相的特征峰E2low和E2high;N+和Xe+注入样品在130和578cm-1附近均出现新峰(包),N+注入样品还在274cm-1出现新峰,而Xe+注入样品在470cm-1附近出现另一新峰包,且这些新峰(包)的相对面积随注入剂量的增大而增大.通过N+和Xe+注入样品拉曼光谱的对比分析,并考虑到注入离子在样品中产生的原子位移损伤,对新峰(包)对应的振动模来源进行了分析,探索了离子注入在ZnO薄膜中引起的结构变化
兰州重离子加速器冷却储存环主环二极铁电源设计；Design of main ring dipole power supply for Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring
No full text主环二极铁电源是兰州重离子加速器冷却储存环(HIRFL-CSR)工程的关键设备和指标要求最高的一台电源,采用了独特的拓扑和控制策略。为满足峰值功率3.15MW(3kA,1.45kV)的输出能力和快脉冲要求,采用了晶闸管整流并联脉宽调制补偿单元的主电路拓扑结构和特殊的控制方式,这套综合方案确保电源满足了全部技术指标。本文介绍了该拓扑结构的原理和优势,讨论了为满足±2×10-4的跟踪误差的要求而采用的控制拓扑和双基准给定的原理,并简介了调试过程和近年来的运行和改进情况
基于DMOS管的电荷灵敏前置放大器设计；Design of A Charge Sensitive Preamplifier Based on DMOS FET
No full text提出了一种由DMOS场效应管构成的电荷灵敏前置放大器,可用于硅,Si(Li),CdZnTe及CsI探测器。该前置放大器采用不同于传统的阻容反馈式的电路结构,完全使用MOS管搭建,该前放的设计完成为设计实现ASIC电路准备了技术基础。由Multisi m仿真结果看出该电荷灵敏前置放大器输出信号上升时间小于15ns,并且具有很好的稳定性
核辐照技术在中药领域中的应用；Application of Nuclear Irradiation to Traditional Chinese Medicine
No full text核辐照应用于中药领域的研究得到人们广泛关注。综述了核辐照在中草药的栽培、育种和消毒等方面的应用,指出辐照诱变技术与生物技术相结合将为提高细胞突变率和加快中草药遗传改良开辟广阔前景