SSC新高频腔设计与分析

Beam matching relationship between the two cyclotrons(SFC and SSC) of HIRFL is briefly discussed, and the frequency band of the new RF cavity is obtained. The new cavity is simulated with the three-dimensional electromagnetic calculation code MAFIA, and the parameters of it such as frequency, Q value, shunt impedance and voltage distribution are worked out and discussed. The simulation results show that the new RF cavity can fully meet the requirements of physics design and space configuration.中文摘要：简要分析了HIRFL SFC与SSC之间的束流匹配关系,给出了新高频腔的频率范围。利用经典三维电磁场数值模拟软件MAFIA对SSC新高频腔体进行了模拟计算,得出了SSC新高频腔体的相关物理参数,并对频率范围、Q值、并联阻抗和电压分布等参数进行了分析。高频腔体的模拟计算结果完全符合SSC回旋加速器改造的物理设计及空间结构要求。

液-液萃取从Th中分离Ac

用234Th、228Ac和139Ce+3做示踪剂,二(2-乙基己基)磷酸做萃取剂,研究了初始HNO3浓度对234Th、228Ac和139Ce+3萃取效率的影响。发现在广泛的酸度范围内,234Th均能被定量地萃取;当HNO3浓度大于2.0mol/L时,228Ac和139Ce3+的萃取效率下降到2%以下。研究了震荡时间对234Th萃取效率的影响,数据显示,1min便可达到萃取平衡。从含大量钍的溶液中分离痕量Ac的实验结果显示,用二(2-乙基己基)磷酸-苯的萃取流程,可使Ac与大量的钍分离,同时Ac的损失又较小。

~(229)Ac具有较小的八极形变性质

通过 1 4MeV中子引起的2 32 Th(n ,α)反应产生2 2 9Ra ,由放射化学分离和γ(X)谱学方法 ,研究了2 2 9Ra到2 2 9Ac的低位态能级。分析结果表明 ,2 2 9Ac具有较小的八极形变性质

多通道AC电源控制器的研制

简要介绍多通道AC电源控制器。该控制器是一个多路程控开关设备,它由计算机进行控制。该仪器是为一个220V交流电源供电系统自动控制与监视系统设计研制的,是该系统的关键前端设备。

~(230)Acβ-延发裂变概率的测定

由60MeV/μ18O离子照射天然钍靶所引起的232Th-2p反应产生230Ra,通过放射化学分离方法从被照射的靶中提取出镭元素并制成薄源,经230Ra230Ac得到230Ac.用云母裂变径迹探测器和PHGeγ射线探测器对来自源中的裂变碎片和γ谱进行记录和测量,借助于所测得的两个裂变事件和γ谱,鉴别了β-延发裂变核230Ac,得到了它的β-延发裂变概率为（1.19±0.85）×10-8.

~(230)Ac β延发裂变

本文叙述了远离beta稳定线新核素合成尤其是beta延发裂变研究的重要意义,介绍了beta延发裂变先驱~(230)Ac的搜索及其延发裂变几率的测定。

~(230)Ac的β延发裂变

用 6 0MeV/u18O离子轰击ThO2 ,通过多核子转移和靶的耗散碎裂反应产生2 3 0 Ra。利用放射化学分离技术 ,将镭与钍及其它反应产物分离并制备成薄镭源。该源对云母裂变径迹探测器暴光 ,用高纯锗探测器测量镭源的γ活度 ;用氢氟酸溶液对云母箔进行蚀刻 ,使用光学显微镜观测云母箔中的裂变径迹。首次观测到了可能来自2 3 0 Acβ延发裂变的两个事件 ,获得它的 β延发裂变几率为 (1 19± 0 85 )× 10 -8。

~(230)Acβ延发裂变的观测(英文)

搜索了２３０Ａｃβ延发裂变．由 ６０ＭｅＶ／ｕ１８Ｏ离子照射２３２Ｔｈ，通过多核子转移反应产生２３０Ｒａ．经放射化学分离和薄的２３０Ｒａ→β－２３０Ａｃ源的制备，获得了 １０８ 个２３０Ａｃ原子．该源对云母裂变径迹探测器曝光．借助于所测的γ能谱和两个裂变事件，鉴别了β延发裂变核２３０Ａｃ，得到了它的β延发裂变几率为（１． １９± ０．８５）× １０－８．

beta-delayed fission of Ac-228

The basic process of an exotic decay mode namely P-delayed fission is simply introduced. The progress status of the study in the world is essentialized. The observation of P-delayed fission of Ac-228 is reported. The radium was radiochemically separated from natural thorium. Thin Ra sources in which Ac-228 was got through Ra-228 ->(beta-) Ac-228 were prepared for observing fission fragments from beta-delayed fission Ac-228. They exposed to the mica fission track detectors, and measured by an HPGe gamma-ray detector. The beta-delayed fission events of Ac-228 were observed and its beta-delayed fission probability was found to be (5 +/- 2) x 10(-12).

Search for beta-delayed fission of Ac-228

Radium was radiochemically separated from natural thorium. Thin Ra-228 ->beta Ac-228 sources were prepared and exposed to mica fission track detectors, and measured by an HPGe gamma-ray detector. The beta-delayed fission events of Ac-228 were observed and its beta-delayed fission probability was found to be (5 +/- 2)x10(-12).

Study of the capacitance coupling in accelerators

The relation between the input impedance and the characteristic parameters of a cavity, such as the resonance frequency, shunt impedance and. the quality factor, has been obtained based on the equivalent circuit of the cavity and the coupling system. Using the matching condition, the ratio of coupling capacitance to the equivalent capacitance of the cavity can be acquired as a function of the characteristic parameters of the cavity, the value of the coupling capacitance can be obtained with a help of a numerical simulation and the perturbation theory, and then the perfect matching between the cavity and the transmission line can be procured. The application of these results on a model cavity is presented too.