考虑电荷交换的RF共振离子引出方法的模拟

为较全面地了解 RF(radio frequency)共振离子引出方法的特性 ,使之更好地用于原子蒸气激光同位素分离(AVL IS) ,用 PIC- MCC方法对其进行了模拟。等离子体中带电粒子在电磁场中的运动用 PIC方法模拟 ,而各粒子间的碰撞用 Monte Carlo方法来模拟 ,碰撞类型主要考虑对目标同位素离子损失影响最大的电荷交换。模拟得出了离子引出时间和碰撞损失率与引出系统的各种参数之间的依赖关系。结果表明 ,为使目标同位素离子快速而低损耗地引出 ,应该采用较大的 RF共振电压幅度和较小的极板间距 ,并且采取措施增加电子温度 ;对于原子蒸气的密度的大小 ,则应在分离产率和碰撞损失率之间权衡。

Simulation of ion extraction by RF resonance method with charge exchange

The characteristics of the RF (radio frequency) resonance method of ion extraction were analyzed to improve atomic vapor laser isotope separation (AVLIS) by using the PIC MCC code to simulate the RF resonance. The movements of the charged particles in the plasma were simulated by PIC and the collisions were simulated by the Monte Carlo method. Among other interactions, charge exchange is the primary collision type which affects the loss of the aimed isotope. The results show that to rapidly extract ions of the aimed isotope with low losses, RF voltage amplitude must be greater, electrode spacing must be narrower, and the electrode temperature should be increased. The atom density should be chosen as a trade off between the production rate and the collision loss.