# TARG5 Targetry for High Repetition Rate Laser-Driven Sources Workshop

Oct 25 – 27, 2021
Dresden
Europe/Berlin timezone

## All-optical plasma density shaping of a cryogenic hydrogen jet target for laser ion acceleration

Oct 26, 2021, 9:00 AM
30m
Dresden

#### Dresden

Helmholtz-Zentrum Dresden-Rossendorf Bautzner Landstraße 400 01328 Dresden Germany

### Speaker

Stefan Assenbaum (Helmholtz-Zentrum Dresden-Rossendorf)

### Description

Target densities near the critical plasma density are of great interest for the laser-ion acceleration community, as new and interesting acceleration mechanisms can occur at these densities due to the effect of relativistically induced transparency.
Designing and builing near-critical densitiy targets with closely defined parameters has thus been the goal of much recent and ongoing target development.

Here, we present our approach for a density tailored near-critical target, that utilizes controlled pre-expansion of a cryogenic hydrogen jet target used at the Draco laser facility at Helmholtz-Zentrum Dresden-Rossendorf (HZDR).
The cylindrical solid hydrogen jet target is irradiated with pump laser pulses in the range of $10^{12}$ to $10^{18}$ W/cm². The expansion of the emerging plasma cloud is studied over several tens of picoseconds by means of high resolution two-color off-harmonic optical probing.
At high pump laser intensities, a simple toy model of the radial density profile of the expanding jet target is applied to estimate the evolution of the plasma density during the expansion process.
We show, how the expansion process can be directly influenced by controlling intensity and temporal shape of the pump laser pulses.

### Primary authors

Stefan Assenbaum (Helmholtz-Zentrum Dresden-Rossendorf) Mr Constantin Bernert (HZDR - Helmholtz-Zentrum Dresden-Rossendorf) Martin Rehwald (Helmholtz-Zentrum Dresden-Rossendorf) Karl Zeil (HZDR)

### Presentation materials

There are no materials yet.