Evolution of plasma sheath in pulsed ion beam extractions

A 1D dynamic sheath model of collisionless plasma is used to calculate the change of sheath edge with time. The calculation is performed for short duration pulses and long duration pulses respectively. For short duration pulses, the plasma sheath edge lags behind the plasma density. For long duration pulses, the velocity of the sheath edge movement is correlative to the initial ion velocity. The steady edge location is correlative to the product of the initial ion velocity and the plasma density.