Optimum laser intensity for the production of energetic deuterium ions from laser-cluster interaction

TL;DR

This study identifies the optimal laser intensity for producing energetic deuterium ions via laser-cluster interactions, demonstrating maximum ion energies and neutron yields with high-power laser pulses and plasma mirrors.

Contribution

It provides the first comprehensive measurement of ion energies and neutron yields over a large interaction volume at high laser powers, highlighting the optimal conditions for fusion.

Findings

Optimal laser intensity for deuterium ion production identified

Maximum ion energy measured at 14 keV

Neutron yields of 7.2x10^6 and 1.6x10^7 achieved

Abstract

We measured, using Petawatt-level pulses, the average ion energy and neutron yield in high-intensity laser interactions with molecular clusters as a function of laser intensity. The interaction volume over which fusion occurred (1-10 mm^3) was larger than previous investigations, owing to the high laser power. Possible effects of prepulses were examined by implementing a pair of plasma mirrors. Our results show an optimum laser intensity for the production of energetic deuterium ions both with and without the use of the plasma mirrors. We measured deuterium plasmas with 14 keV average ion energies, which produced 7.2x10^6 and 1.6x10^7 neutrons in a single shot with and without plasma mirrors, respectively. The measured neutron yields qualitatively matched the expected yields calculated using a cylindrical plasma model.