偏滤器靶板附近氦输运的蒙特卡洛模拟

本文用Monte Carlo方法模拟了偏滤器扁平抽气收集板附近区域的氦原子输运。考虑了氦原子被电子碰撞电离,氦原子与等离子体离子之间的弹性散射等原子过程以及离子的热运动和沿磁力线的流动。计算表明当偏滤器等离子体密度在7cm距离内从里向靶板逐渐增加约4.7倍,而温度分布保持不变时,氦灰返回靶板的几率比密度在7cm内向靶板递减4.7倍的通常正分布提高约45％。磁力线与靶板的交角、靶板的温度,边缘等离子体鞘层电位以及不同的靶材料对氦返回靶板几率的影响作了比较。得到的结果对托卡马克聚变裂变增殖堆孔栏和偏滤器工程设计有参考价值。

MONTE CARLO SIMULATION OF HELIUM TRANSPORT IN THE VICINITY OF DIVERTOR PLATE

A Monte Carlo code "IDHET" has been utilized for simulating the transport of neutral helium near divertor target plate. The atomic processes of electron impact ionization and elastic scattering by plasma ions are included. The thermal and streaming motion of the ions along the magnetic field is also taken into consideration. Calculations show that the probability of neutral helium turning back to the target plate will increase by 45% as compared with that under an ordinary density profile if the plasma density close to the divertor plate is 4.7 times higher than that at 7cm towards the core plasma. The effects of angle between the magnetic field and target plate,the temperature of plate,the edge plasma sheath and pre-sheath potential and target materials on the probability of neutralized helium scattered by the plasma ions back to the plate are demonstrated. The results may be useful for the design of divertor and pumping limiter in Tokamak Engineering Test Breeder.