Method of processing ion energy distributions using a Thomson parabola ionspectrograph with a microchannelplate image converter camera

A Thomson parabola ion spectrograph (TP) is a very useful tool for the inve stigation of pulsed laser ablation. Measurements performed with the TP give useful information about physical processes, ion species and their energy distributions, as well as charge states. For ions with the lower charge sta tes, q < 20, complete information about energy distributions of all ionizat ion states of ions can be obtained from a single laser shot. For ions with higher ionization states, parabolas generated in the TP interfere and it is impossible to get energy distributions for all the ion species. In this si tuation, the registered ions are composed of a few groups with different ch arge states and different energies. The TP enables the charge states and en ergetic ranges of different ion groups to be estimated. This presentation d escribes a method of processing experimental results, obtained from a TP, u sing a microchannelplate (MCP) image converter. Ion energy distributions fo r C1+-C6+ and Ta1+-Ta12+ are shown, and the effects of correcting the obtai ned ion energy distributions for the detection efficiency of the MCP are il lustrated. (C) 2000 American Institute of Physics. [S0034-6748(00)65902-6].