Study of accelerated ion energy and spatial distribution with variable thickness liquid crystal targets

2017/04/26 by Patrick Poole, Poole, P. L., C. Willis +7
Engineering · Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Laser-Plasma Interactions and Diagnostics #Laser-induced spectroscopy and plasma #Plasma Physics (physics.plasm-ph)

paper · pdf · doi:10.48550/arxiv.1704.08287

openalex publication_date 2017/04/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28

Abstract

We report on laser-based ion acceleration using freely suspended liquid crystal film targets, formed with thicknesses varying from 100 nm to 2 μm for this experiment. Optimization of Target Normal Sheath Acceleration (TNSA) of protons is shown using a 1 × 10²⁰ W/cm², 30 fs laser with intensity contrast better than 10^-7:1. The optimum thickness was near 700 nm, resulting in a proton energy maximum of 24 MeV. Radiochromic film (RCF) was employed on both the laser and target normal axes, revealing minimal laser axis signal but a striking ring distribution in the low energy target normal ion signature that varies with liquid crystal thickness. Discussion of this phenomenon and a comparison to similar observations on other laser systems is included.

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• Multivariate scaling of proton and ion energies, divergence, and charge states in Target Normal Sheath Acceleration
• Enhancing proton acceleration by using composite targets
• Effects of Laser Polarization on Target Focusing and Acceleration in a Laser-Ion Lens and Accelerator