High-repetition-rate ( kHz) targets and optics from liquid microjets for high-intensity laser–plasma interactions

Abstract

High intensity laser-plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, high repetition rate and high average power requirements for many applications are not satis ed by the lasers, optics, targets, and diagnostics currently employed. Here, we address the need for high repetition rate targets and optics through the use of liquids. A novel nozzle assembly is used to generate high-velocity, laminarowing liquid microjets which are compatible with a low-vacuum environment, generate li le to no debris, and exhibit precise positional and dimensional tolerances. Jets, droplets, submicron thick sheets, and other exotic con gurations are characterized with pump-probe shadowgraphy to evaluate their use as targets. To demonstrate a high repetition rate, consumable, liquid optical element, we present a plasma mirror created by a submicron thick liquid sheet. is plasma mirror provides etalon-like anti-re ection properties in the low-eld of 0.1% and high re ectivity as a plasma, 69%, at a repetition rate of 1 kHz. Practical considerations of uid compatibility, in-vacuum operation, and estimates of maximum repetition rate in excess of 10 kHz are addressed. e targets and optics presented here enable the use of relativistically intense lasers at high average power and make possible many long proposed applications. . All diode-pumped, highrepetition-rate advanced petawa laser system (hapls).

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] .…”

Evidence of radial Weibel instability in relativistic intensity laser-plasma interactions inside a sub-micron thick liquid target

“…The experiment, displayed in Fig. 1a, was performed with a relativistic intensity, short pulse laser incident on a thin (~0.5 μm) target 28 . The laser-target interaction was illuminated by a short pulse probe beam created from frequency doubling different pulses of a common oscillator in a scheme described in the Feister et al 10 and in the Methods section.…”

Automation of Target Delivery and Diagnostic Systems for High Repetition Rate Laser-Plasma Acceleration

“…Moreover, there are strict technical requirements for the target system, such as fast target refreshing, positioning, and alignment. Currently, a wide range of targets has been developed for laser-plasma acceleration, such as thin solid foils, tapes [19], gas [20] or liquid jets [21,22], clusters [23], cryogenic targets [24,25], and liquid crystals [10,26]. Hereafter, we aim to address the need for high repetition rate planar thin target delivery as a continuous sheet of material (thin foil) that is refreshed by a motorized stage.…”