The numbers, flow velocities, and temperatures of the positive ions emitted by helium and argon plasmas pulsed into an evacuated region by a plasma gun are determined by a time‐of‐flight analysis on freely expanding ions. Times of plasma release are also calculated. It is shown that the time‐of‐flight technique is applicable even with statistical variations in plasma characteristics observed under apparently identical conditions of plasma production. A slug‐mode description of the average behavior of the gun is seen to agree with the time‐of‐flight analysis if ion recombination is assumed.