电子束的绝热展开

Adiabatic Expansion of Electron Beam

考虑空间电荷效应，用数值方法模拟计算了电子束绝热展开过程．当初始磁感应强度与最终磁感应强度之比为Ｋ时，电子束横向温度由初始值Ｔｉ降低 Ｔｉ／Ｋ．研究了不同能量、不同流强的电子束达到预期的绝热展开倍数所需的最低磁感应强度．

The temperature of electron beam is an important parameter in electron cooling device. Transverse temperature will be reduced When an electron beam passes through a negative gradient magnetic field. Some theoretical approaches on adiabatic expansion are presented here. Adiabatic expansion of the electron beam moving in different magnetic fields with different energy and current was investigated by computer simulation. The results show that the transverse temperature of the electron beam is reduced by a factor equal to the ratio between the initial and final magnetic field strengths, provided that the field change is adiabatic with respect to the cyclotron motion of the electrons.