Reduced density channels in air produced by a double pulsed electron beam

The radial profile of a reduced density channel in air produced by a double pulsed electron beam has been measured by use of a simple laser deflection technique, sensitive to density changes of 1016 cm−3 in air. Measurements indicate a pressure dependence in channel depth and in the relationship between beam and channel profiles. Measured channel and shock wave behaviors agree with predictions of a one-dimensional hydrodynamics code. Channel decay rates were negligible for times t<1 ms.