Emission characteristics and stability of laser ion sources

Analysis of ion sources based on a time-of-flight signal function is applied to quantify their emission characteristics as the hidden partial currents of the ionized species constituting the total measured current the centre-of-mass velocity of individual charge states their abundance and the ion temperature (C) 2010 Elsevier Ltd All rights reserved

A new classification of laser ion sources concerning their pulse-to-pulse reproducibility in the ion emission is proposed In particular we distinguish between plasmas according to the electron distribution and changing its characteristics at a laser intensity threshold of 10(14) W/cm(2) Well reproducible continuous pulsed ion currents are typical for the intensity below the threshold In contrast to this plasma the two-temperature plasma arising for the intensity above this threshold shows not only a separation of charges in space and time during the expansion but It also shows outbursts of ions similar to a self-pulsing instability leading to a chaos The sequence of fast ion outbursts visible on the time-resolved ion currents is sensitive to the details of non-linear interaction of the laser beam with the generated plasma