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 1014 W/cm2. 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.Analysis of ion sources based on a time-of-flight signal function is applied to quantify their emission …