In-situ, variable thickness, liquid crystal film target inserter for moderate repetition rate intense laser applications

TL;DR

This paper introduces a novel in-situ liquid crystal film target inserter capable of producing variable thickness targets at moderate repetition rates, enhancing laser-matter interaction experiments and ion acceleration optimization.

Contribution

The paper presents a new device that forms and inserts variable thickness liquid crystal films in situ at high repetition rates, enabling real-time target optimization for intense laser applications.

Findings

Device can produce films from 10 nm to over 10 μm in thickness.

Repetition rate exceeds 0.1 Hz for sub-100 nm films.

Characterization performed at Ohio State's Scarlet laser facility.

Abstract

Liquid crystal films have recently been demonstrated as variable thickness, planar targets for ultra-intense laser matter experiments and applications such as ion acceleration. By controlling the parameters of film formation, including liquid crystal temperature and volume, their thickness can be varied on-demand from 10 $nm$ to above 10 $\mu m$. This thickness range enables for the first time real-time selection and optimization of various ion acceleration mechanisms using low cost, high quality targets. Our previous work employed these targets in single shot configuration, requiring chamber cycling after the pre-made films were expended. Presented here is a film formation device capable of drawing films from a bulk liquid crystal source volume to any thickness in the aforementioned range. This device will form films under vacuum within 2 $\mu m$ of the same location each time, well within the Rayleigh range of even tight $F/ \#$ systems. The repetition rate of the device exceeds 0.1 $Hz$ for sub-100 $nm$ films, enabling inexpensive, moderate repetition rate plasma target insertion for state of the art lasers currently in use or under development. Characterization tests of the device performed at the Scarlet laser facility at Ohio State will be presented.