氢原子束在大气长程传输中自剥离效应研究

氢原子束在大气传输时，束流粒子与大气粒子碰撞电离形成的大气剥离效应，以及和大气剥离产生次级粒子碰撞电离形成的自剥离效应，是造成氢原子束能量损失的重要机制。考虑到自剥离效应成因复杂，虽然目前已有一些理论方面的研究结果，但对其发生机理和对束流损失效果尚未有实验或数值模拟方面的工作，因此，通过对自剥离效应的发生机理和对束流损失的影响进行分析，进一步完善了自剥离效应理论，在通过束流传输方程验证了粒子云网格-蒙特卡罗法对氢原子束大气传输仿真模拟适用的基础上，将仿真结果与自剥离理论进行了对比，验证了自剥离效应理论的适用性。模拟结果表明，自剥离效应是由束流被大气电离产生的带电次级粒子团在地磁场的影响不停地穿越束流导致的，且自剥离效应的强弱与原子束的密度有关，束流密度越大，自剥离效应越强，对束流的影响越大。

Study on beam-induced-stripping effect of hydrogen atom beam in long distance propagation in atmosphere

When the hydrogen atom beam is transmitted in the atmosphere, the atmospheric stripping effect formed by the collision ionization between the beam particles and the atmospheric particles and the self-stripping effect formed by the collision ionization with the atmospheric particles are the important mechanisms causing the energy loss of the hydrogen atom beam. Due to the complex causes of self-stripping effect, although there are some theoretical research results, there is no experimental or numerical simulation work on its occurrence mechanism and beam loss effect. Therefore, this paper further improves the theory of self-stripping effect by analyzing the occurrence mechanism of self-stripping effect and its influence on beam loss. On the basis of verifying the applicability of particle cloud grid Monte-Carlo method to the atmospheric transport simulation of hydrogen atom beam through the beam transport equation, the simulation results are compared with the self-stripping theory, which basically verifies the applicability of the self-stripping effect theory. The simulation results show that the self-stripping effect is caused by the charged secondary particle clusters produced by the beam ionization by the atmosphere constantly passing through the beam under the influence of the geomagnetic field, and the strength of the self-stripping effect is related to the density of the atomic beam. The greater the beam density, the stronger the self-stripping effect, and the greater the influence on the beam.