Whether abnormal energy electrons are being produced in electric discharges in dense gases?

Reviewing results of experimental research of picosecond pulses of runaway electrons (REs) generated by discharges in dense gases at multiple overvoltages, including, along with routine measurements of voltage pulses and RE current, direct measurements of RE energy distributions, pressure dependence of RE numbers and experiment with retarding voltage similar to the accelerating voltage, a reality of the effect of 'abnormal energy' REs is being substantiated. With this goal we emphasize non-conventional qualitative RE characteristics rather than quantitative. [ABSTRACT FROM AUTHOR]