PULSED SHEATH DYNAMICS IN A SMALL CYLINDRICAL BORE

The temporal evolution of the plasma sheath in small cylindrical bores and planar gaps is calculated for zero-rise-time voltage pulses. The ions are modeled as a cold, collisionless fluid, and the problem is re duced to the solution of two coupled, first-order, ordinary differenti al equations. These equations are solved analytically for the planar c ase, and numerically for the cylindrical case. The maximum ion impact energies are 50% and 36.8% of the maximum potential drop in the planar and cylindrical cases, respectively. Ion impact energy decreases with the square of the radius of the bore.