Transport efficiency of intense relativistic electron beam in pre-formed plasma channel

Relativistic electron beam (REB: 300keV, 5kA, 60ns) transport efficiency has been investigated by injecting the REB into a preformed argon plasma channel in the drift tube. Transport efficiency has been obtained from two Rogowski coils separated by 20cm each other. At the vacuum drift tube, the transport efficiency is about 20%, in which the propagation beam current is below the space charge limiting current. It is found that the transport efficiency could be increased up to 48% when the pre-formed plasma channel density is 1.3×10¹¹cm⁻³, which is close to that of REB.