The influence of stress on electron emission initiated by a shock wave from a heterogeneous material (granite)

An electrical breakdown of the air near the surface of a compressed granite plate initiates a shock wave in it. Having reached the back side of the plate, the shock wave causes successive (with an interval of $\sim$50 ns) emission of plasma jets presumably consisting of positively charged ions. The intensities of the jets are distributed exponentially. While the compression pressure P does not exceed $\sim$0.9–0.95 of the failure pressure $P_f$, it does not affect the number and efficiency of the radiation sources. At $P\approx (0.9-0.95)P_f$, the shock wave causes the emergence of a crack destructing the sample. Simultaneously, the number and efficiency of ion sources increase 3–4-fold. This phenomenon is explained by an increase in the concentration of clusters of dislocations upon the creep of the sample.