Year: 2023
Type: article
Abstract: The interaction of a high-intensity ultrashort laser pulse with a few micrometers-thick hydrocarbon target is known to accelerate protons/ions to multi-MeV, on the rear side of the target, via the mechanism of target normal sheath acceleration. Micro-structuring the target front is one of the promising approaches to enhance the cutoff energy as well as to reduce the divergence of accelerated protons/ions. In this paper, the interaction of a normally incident intense laser pulse with targets having single micrometer-sized grooves, at their front side, of semi-circular, triangular, and rectangular shapes has been studied by using two-dimensional particle-in-cell simulations. It is observed that as compared to a flat target for targets with a rectangular groove at the front side the focused hot electron beam at the rear side results in an approximately fourfold increase in the cutoff energy of accelerated protons. For triangular and semi-circular groove targets, the cutoff energy remains comparatively lower (higher than the flat target though). The angular divergence of the accelerated protons/ions is also found to be relatively much lower in the case of a rectangular groove.
Source: Physics of Plasmas
DOI: 10.1063/5.0143369
Authors: Imran Khan, Vikrant Saxena
Institution: Indian Institute of Technology Delhi
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G3307459565, G987666641
OpenAlex ID: W4380323964