Plasma parameters of dense gas discharge with runaway electrons

Summary form only given. The discharge with runaway electrons in dense gas (for short - runaway discharge, RD) has plasma characteristics essentially different in comparison with plasma characteristics of all other discharges in dense gas. The basic particularity of RD is connected with generation of sub-relativistic (20-400 keV) electrons in discharge volume during sub-nanosecond period. Last property complicates essentially the study of RD plasma and demands a development of new methods for some basic parameters measurement at RD. In particular, for measurement of RD runaway electron current and average energy we had developed a technique on the basis of voltage measurement on pure inductive collector of current: U_thetas = L_sd(i _D + thetasi_B)/dt, where L_s is collector inductance, i_D is the displacement current in the collector circuit, i_B is the current of fast electron beam through the collector butt, thetas is the fast electron transmission factor of the screen or foil placed between the anode and collector. On the fig. 1 the typical example of such measurements is resulted on which the physics of processes in RD plasma is discussed