High repetition rate, multi-MeV proton source from cryogenic hydrogen jets

Abstract

We report on a high repetition rate proton source produced by high-intensity laser irradiation of a continuously flowing, cryogenic hydrogen jet. The proton energy spectra are recorded at 1 Hz for Draco laser powers of 6, 20, 40, and 100 TW. The source delivers ∼1013 protons/MeV/sr/min. We find that the average proton number over one minute, at energies sufficiently far from the cut-off energy, is robust to laser-target overlap and nearly constant. This work is therefore a first step towards pulsed laser-driven proton sources for time-resolved radiation damage studies and applications which require quasi-continuous doses at MeV energies.

Petawatt and exawatt class lasers worldwide

“…With petawatt lasers at shot rates that are of the order of 10 Hz for ELI-BL [383] , and with a petawatt system at ELI-ALPS running at 10 Hz and a terawatt system running at 100 Hz [384] , there is at least two orders of magnitude increase in the number of targets that can be shot; currently there is insufficient capacity to manufacture enough targets using conventional techniques. To overcome this challenge, high-repetition-rate liquid targets have been proposed [385][386][387] , and recently there has been a demonstration of multi-MeV proton acceleration from sub-micron liquid sheet targets at 1 kHz repetition rates [388] .…”

Study of the parameter dependence of laser-accelerated protons from a hydrogen cluster source

“…A hydrogen droplet source for application in laser-plasma physics was developed by Costa Frage et al [15]. In the framework of laser-driven particle acceleration Gauthier et al [16,17] used a jet for the purpose of accelerating protons, while a further investigation of the target-geometry dependence was studied by Obst et al [18]. A drawback of these kind of structures like droplets, jets or ribbons is on the one hand the position stability as e.g.…”

“…A drawback of these kind of structures like droplets, jets or ribbons is on the one hand the position stability as e.g. discussed in [17], where the spatial jitter overcomes the diameter of the target. On the other hand, this goes along with the general requirement to align and focus the laser reliably onto a specific position in space.…”

A sensitive EUV Schwarzschild microscope for plasma studies with sub-micrometer resolution

“…Recently, it has been demonstrated that cryogenic hydrogen jets 3 allow for studies of electron-ion equilibration 4 and the generation of pulsed proton beams. [5][6][7] The reliable shot-to-shot characterization of jet thickness, pointing jitter, relative alignment with tiny laser foci and potentially the time-resolved probing of the hydrodynamic plasma expansion, calls for high-resolution a) ulf.zastrau@xfel.eu single-shot imaging with sub-micrometer resolution. Static, time-integrating microscopy in the sub-µm regime has already demonstrated the advantage of extreme ultraviolet (EUV) radiation using transmissive 8 and reflective optics.…”