MULTIPLY-CHARGED IONS OF HEAVY-ELEMENTS PRODUCED BY AN IODINE LASER WITH SUBNANOSECOND PULSES

Multiply charged ions of Ta, W, Pt, Au, Pb, and Bi, produced by the ph otodissociation iodine laser system PERUN (lambda = 1.315 mu m, E-L < 40 J, tau(L) similar to 350 ps) are reported. The ions with maximum ch arge states around 50+ and with energies of several MeV were registere d at a distance of about 2 m from a plasma plume. The existence of sev eral groups of ions corresponds to the different processes that occur in the plasma. The influence of different factors on the ion productio n is discussed. Measured ion current densities higher than 10 mA/cm(2) in the distance of I m from the target demonstrate the superiority of laser ion sources. (C) 1998 American Institute of Physics.