Experimental verification of TNSA protons and deuterons in the multi-picosecond moderate intensity regime

Abstract

Ion acceleration from high intensity short pulse laser interactions is of great interest due to a number of applications, and there has been significant work carried out with laser energies up to a few 100 J with 10's of femtosecond to 1 ps pulse durations. Here, we report results from an experiment at the OMEGA EP laser, where laser energy and pulse length were varied from 100 to 1250 J and 0.7–30 ps, respectively, in the moderate ([Formula: see text]) laser intensity regime. Ions and electrons were simultaneously measured from disk targets made of CH and CD by a Thomson parabola and a magnetic spectrometer, respectively. Measurements showed that the electron temperature, [Formula: see text] (MeV), has a dependence on the laser energy, [Formula: see text] (J), and pulse duration, [Formula: see text] (ps), and its empirical scaling was found to be [Formula: see text]. The maximum proton and deuteron energies are linearly dependent on the electron temperature, [Formula: see text] and [Formula: see text], respectively. A significant increase in proton numbers with the laser energy was also observed. The increase in the maximum proton energy and proton count with higher energy longer duration pulses presented in this article shows that such laser conditions have a great advantage for applications, such as the proton radiograph, in the moderate laser intensity regime.