Experiments investigating the effects of the accelerating gap voltage pulse on the ion focused (IFR) high current electron recirculators

The authors have established experimentally that pulsing the accelerating gap of the ET-2 cavity puts the electrons and ions of the ion focusing regime (IFR) plasma channel into motion. As a result of the electron motion, two types of disturbances propagate axially into opposite directions: (1) electrons move to the left of the gap, and (2) a sheath moves to the right (direction of gap electric field). Both disturbances cause the Rogowski coils to register a 200-300-A current in the same direction. The argon ions of the IFR channel escape radially with velocities equal to 1.2*10/sup 7/ cm/s and take 400 ns to hit the 5-cm-radius pipe. Cusp magnetic fields or possibly transparent grids upstream and downstream from the accelerating gap can decouple it from the IFR channel. >