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 ~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 ~0.9–0.95 of the failure pressure P f , it does not affect the number and efficiency of the radiation sources. At P ≈ (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.