梯度磁场中静电波引起的粒子随机运动

本文讨论了一般非均匀梯度磁场下任意方向传播的静电波引起粒子随机运动的非线性效应。用正则久期扰动理论给出包含粒子周期运动和波振荡之间非线性共振的哈密顿量。根据Chirikov岛重叠条件给出一般梯度磁场下粒子进入随机态的临界波幅值。分析表明,相对均匀磁场,在弱非均匀情形下,该临界值降低,意味着粒子更易进入随机态。 关键词：

THRESHOLD OF STOCHASTIC MOTION OF CHARGED PAR-TICLES IN GRADIENT MAGNETIC FIELD BY ELECTROSTATIC WAVE

Nonlinear effects of the gradient inhomogeneity of the magnetic field on the stochastic motion of charged particles due to an electrostatic wave propagated arbitarily relative to the magnetic field are considered in this paper. A sequence of canonical transformations is preformed to obtain a Hamiltonian explicitly exhibiting the possibility of the resonance between the periodic motion of particles and oscillation in the wave. The theoretical analysis shows that, due to the inhomogeneity of the magnetic field, the threshold for the onse of the stochasticity is changed and, in the case of weak inhomogeneity of the magnetic field, it is lowered, which means that the stochasticity appears more easily than in the case of uniform magnetic field.