STOCHASTIC MOTION OF A CHARGED-PARTICLE IN A MAGNETIC-FIELD .1. CLASSICAL TREATMENT

We study the dissipative, classical dynamics of a charged particle in the presence of a magnetic field. Two stochastic models are employed, and a comparative analysis is made, one based on diffusion processes a nd the other on jump processes. In the literature on collision-broaden ing of spectral lines, these processes go under the epithet of weak-co llision model and Boltzmann-Lorentz model, respectively. We apply our model calculation to investigate the effect of magnetic field on the c ollision-broadened spectral lines, when the emitter carries an electri cal charge. The spectral lines show narrowing as the magnetic field is increased, the narrowing being sharper in the Boltzmann-Lorentz model than in the weak collision model.