A Cryogenic Hydrogen Ribbon for Laser Driven Proton Acceleration at Hz-Level Repetition Rate

Abstract

We report on recent progress in deploying a continuous solid hydrogen ribbon as a debris-free and renewable laser-driven source of pure proton beams generated by a 30-fs laser with ∼1-J laser energy focused on target at relativistic intensities of ∼1019 W/cm2 and repetition rate of 0.1 Hz. The stability of the ribbon position versus the laser interaction point and maximum repetition rate was tested up to 3.3 Hz. The acceleration of protons with cut-off energies up to 1.5 MeV is demonstrated using a 100-μm thick hydrogen ribbon as proof-of-principle capability of the relatively thick target delivery system. The laser-target geometry presented demonstrates an experimental technique that can potentially enables the operation of a laser–plasma source at Hz-level repetition rate.

Proton imaging of high-energy-density laboratory plasmas

“…A number of targetry solutions suitable for highrep-rate operations are currently being developed and tested. These include tape targets, where a continuously moving foil tape allows mechanical refreshment of the laser-impacted surface between shots (Noaman-ul Haq et al, 2017;Dover et al, 2020), free-flowing water sheets (Puyuelo Valdes et al, 2022), and cryogenic hydrogen targets (Obst et al, 2017;Chagovets et al, 2022). The aforementioned approaches can provide planar targets with thicknesses in the micron to tens of micron range, leading to beams with the expected TNSA properties, with beam production demonstrated thus far at repetition rates of up to 1 Hz employing petawatt-class laser pulses.…”