THE FRICTION AND DIFFUSION-COEFFICIENTS WITH MAXWELLIAN SCATTERS

The Fokker-Planck coefficients for Coulomb interaction, or the frictio n coefficient (Delta ($) over right arrow v(alpha)) (the average chang e in velocity) and the diffusion coefficient (Delta ($) over right arr ow v(alpha)Delta ($) over right arrow v(alpha)), are evaluated by an a ppropriate variable change technique. This approach reduces the five-f old integral expressions of the Fokker-Planck coefficients to one-fold integral without meeting the divergence difficulties. A new Debye cut off parameter Delta v(amin) instead of the customary theta(min) cutoff avoids the error incurred through the customary neglecting of velocit y dependence of the Coulomb logarithm. The dominant terms of the new r esults are similar to Chandrasekhar's results. A non-dominant term, wh ich can exceed the dominant one in the case of v(alpha)(2) > v(beta t) (2) In Lambda, is added for (Delta v(alpha parallel to)(2)).