THE MAGNETIC PRESHEATH BOUNDARY-CONDITION WITH EXB DRIFTS

It is demonstrated rigorously that the effects on a one-dimensional, c ollisionless, magnetic presheath with oblique magnetic field B of a un iform tangential electric field, causing a drift v(D) = E x B/B-2, are equivalent to a transformation to a frame moving tangential to the su rface. Therefore, in particular, the Chodura solution with parallel ve locity nu(parallel to) = C-s, (the sound speed) is transformed into a solution with nu(parallel to) = C-s + nu(D)/tan alpha, where alpha is the field angle to the surface. (C) 1996 American Institute of Physics .