Influence of laser pulse parameters on characteristics of a source of multicharged metal ions based on laser-induced medium-power spark discharge

The dynamics of laser-induced vacuum spark discharge with storage energy not exceeding 25 J has been studied in a broad range of laser pulse energies and power densities. It is shown that, using discharge-initiating laser pulse of nanosecond duration, it is possible to obtain stable single pinching of cathode jet plasma at a storage voltage above 10 kV. Plasma pinching is accompanied by the generation of a beam of multicharged ions of the cathode material (aluminum) up to Al$^{8+}$. The maximum energies of ions obey the scaling relation $E_{\mathrm{max}} = 5ZeU_0$ that has been obtained previously for a low-voltage discharge. An increase in the laser pulse energy leads to growth of the average beam charge and a sharp decrease in the ion energy.