Emission Of Multipulcharged Ions From Laser-Triggering Vacuum Discharge

Abstract

The possibility of using plasma of the laser-induced vacuum discharge as a source of multiplecharged ions is considered. To this end, a sequence of measurements of the ion emission from discharge plasma was made. The laser radiation was focused on the anode surface in the focal spot with diameter D≤250 µm and with intensity on the target q≈5 ×10 9 W/cm 2 . The laser energy El = 50 ÷ 60 mJ. The choice of given geometry in this experiment has allowed us to successfully detect the ions emitted at a small angle (≈   with respect to the discharge axis. We have already established earlier that the ion yield, in the case of focusing laser radiation on the cathode of discharge system, is significantly less.The use of the storage capacitor of C=0.22 µF enabled us to vary the amount of discharge energy in the range of Edr =5÷24 J. Depending on the discharge energy the intensity of ion emission and the spectrum of charge states changed. Our measurement results allowed us to make an assumption that the work in the range of discharge energies Edr = 10÷14 J is the most effective from the point of view of the quantity of emitted multiple-charged ions. The average ion flux density was Wp = (1.5÷ 3)·10