潘宁阱中电子等离子体稳态的数值模拟

NUMERICAL SIMULATION OF THE STEADY STATE OF ELECTRON PLASMAS IN THE ELECTRON BEAM PENNING TRAP

应用粒子模拟方法研究了电子束潘宁阱中的非中性等离子体的稳定状态及其定标关系。数值模拟结果表明 ,给定电子的初始分布和外场条件后 ,潘宁阱中可以出现聚心状态的电子等离子体 ,中心电子密度可达 10倍布里渊密度 ;电子密度分布与理想的 1 r2 关系有差别 ,阱中的电子数越多 ,差别越大。

A particle in cell code has been developed to simulate the steady state of electron plasmas in an electron beam Penning trap and to study its scaling law.Results show that electron plasma with a dense core appears in the trap under given distribution for initial electrons and applied electric field,and its core electron density can be 10 times of Brillouin density which is independent of the amount of initially injected electrons and is proportional to the applied electric field.The density profile in the trap is not exactly the ideal one of 1/r 2.The more the electrons in the trap are,the larger the discrepancy in the profile is.The relaxation time for the system steady state is proportional to the applied electrical field and inversely proportional to the amount of electrons in the trap.