Tomographic characterization of gas jets for laser-plasma acceleration with increased sensitivity

Abstract

We present a new interferometric technique for gas jets density characterization employing a Wollaston shearing interferometer. The distinctive feature of this setup is the double pass of the probe beam through the gas target facilitated by a relay-imaging object arm that images the object on itself and preserves the spatial information. The double pass results in two-fold increase of sensitivity at the same time as the relay-imaging enables the characterization of gas jets with arbitrary gas density distribution by tomographic reconstruction. The capabilities of the double-pass Wollaston interferometer are demonstrated by tomographic density reconstruction of rotationally non-symmetric gas jets that are used as gas targets for the betatron X-ray source at ELI-Beamlines.

Development of the multidisciplinary x-ray sources at the ELI Beamlines facility

“…In a double-pass configuration, a two-fold increase in the sensitivity compared to the standard single-pass configuration was found. 18,19 We further extend the configuration with four passes by employing the polarization switching of the probe beam, and we observed a four-fold increase in the phase sensitivity as shown in Fig. 3.…”

Update on LPA based X-ray sources at ELI Beamlines

“…The scheme of four pass interferrometry is shown in 2a. In a two-pass configuration a two-fold increase in the sensitivity compared to the standard single-pass configuration [20,21] and with four-fold in four pass was found. Fig.…”

Laser-machined two-stage nozzle optimised for laser wakefield acceleration

“…However, FLICE, laser trepanning or EDM of micrometre-scale diameters are limited to low millimetre-scale depths (Takahashi et al 2013;Tomkus et al 2019;Chiomento et al 2021). For larger nozzles, nanosecond rear-side milling is an appealing approach, as centimetre-sized nozzles can be formed with channel diameters down to 100 µm (Tomkus et al 2018;Chaulagain et al 2021). Additionally, this technique can form converging-diverging channels up to some angle in a single step (Chaulagain et al 2021).…”

“…For larger nozzles, nanosecond rear-side milling is an appealing approach, as centimetre-sized nozzles can be formed with channel diameters down to 100 µm (Tomkus et al 2018;Chaulagain et al 2021). Additionally, this technique can form converging-diverging channels up to some angle in a single step (Chaulagain et al 2021). In this paper, we demonstrate fabrication of a two-stage nozzle from a single block of fused silica using the rear-side milling technique only.…”