Observation of different Ta and Pt ion groups produced by laser radiation with the intensities of I λ2∼1015 W cm−2 μm2

Abstract

Ions produced in a process of interaction of the intense laser radiation of the iodine laser system PERUN (λ=1.315 μm, EL⩽50 J, τ∼350 ps, Iλ2∼1015 W cm−2 μm2) with the solid state tantalum and platinum targets have the ionization states from z=1 up to z∼50 and energies at least a few MeV. The Thomson parabola (TP) ion spectrograph with a registration system based on the micro channel plate (MCP) used in the experiment, gives a general view of ionization states and energies of all types of ions created in one laser shot. The data registered by the PC, gives on-line information on the obtained experimental results. As shown, the calibration measurements of MCPs, made with Ta ions (MCPs different from these used with the TP), analog particle gain of the MCPs rises with the increase in the ion charge states and energy. This attribute causes an increase in sensitivity of MCPs on the highly charged, high energy ions. The registered ions are composed of a few groups of ions with different charge states and different energies. In the experiment with the TP, the ring, ion collector (IC), coaxial with its axis has been used. From a comparison of the velocities of different ion groups registered by the IC and by the TP, the quantity of ions in different ion groups was estimated.