在线同位素分离装置的靶系统设计方法

产生放射性核束的在线同位素分离装置的靶系统设计是整个装置产生效率的关键环节.在ORNL的窄高斯分布的离子注入模型的基础上,研究了不同的靶的几何形状和尺寸、不同的温度条件、半衰期不同的放射性核素等对释放时间特性的影响,这对设计具有快速释放过程的靶系统,具有直接的实用价值.基于德国ZFK关于表面物理的实验测量数据,用MonteCarlo统计的方法来模拟放射性核素从靶材料表面到在线离子源的电离室的传输过程,对大量的放射性核素–传输管材料组合,和不同尺寸的传输管进行了统计计算,从这些统计计算中得到了可用于传输管工程设计的图表和经验公式.

Design Method for ISOL′s Target System

The target system design is one of the key problems in the ISOL facility for RIB generation. In this paper,the diffusion and adsorption processes in the target materials are simulated so as to investigate the release time of radioactive species from the uniform or Gaussian distribution,cylindrical,spherical or planar target materials operated at different temperatures based on the idea of using ion implantation at HRIBF for the selection of RIB targets. The effusion process from the surface of the target material to the ionization chamber of the online ion source is also investigated in this paper. The Monte-Carlo techniques are used for the numerical simulation based on the measurement data of surface physics from ZFK,Germany. The empirical formulas and the tables of characteristic effusive-flow times for various particles through tubes of different dimension and material are extracted from the simulation. One can design the dimension of the effusion tube and determine the material for the tube by using the formulas and the tables.