Ultra-intense short pulse ion acceleration from near solid density nanofoams

Generating ~tens of keV ion distributions at near solid density has the potential to allow nuclear reaction cross section measurements of relevance to astrophysics, including the CNO stellar cycle. Recently, a platform has been proposed [1] which can accomplish this using an ultra-intense short pulse laser, with the possibility of data collection at high shot rates. An unstructured nanofoam CH or CD target, consisting of ~100 nm randomly oriented ligaments, is shot with a femtosecond-scale laser. Hot electrons are produced which stream through the foam, accelerating ions normal to the ligament surfaces and creating a plasma in which charged particle reactions can take place. Experimental results using these targets at the Ohio State Scarlet laser facility in its f/17 mode (~5x10¹⁹ W/cm², 40 fs) will be presented. Proton and deuteron acceleration from CD and CH nanofoam targets is studied as a function of foam composition and incident laser parameters.

1. Kemp et al. “Generating keV ion distributions for nuclear reactions at near solid-density using intense short-pulse lasers,” Nature Communications, 10, 4156 (2019).