Speaker
Description
Modern laser facilities for Laser-Driven Plasma Acceleration (LDPA) reach intensities < $10^{20}W/cm^{2}$ making them capable of accelerating particles up to the relativistic regime. In order to have an efficient acceleration mechanism the laser pulse needs to interact with the laser at its top intensity, nonetheless effects like ASE and pre-pulses can generate intensities high above the metal and dielectric ionization thresholds (~~$10^{11}W/cm^{2}$ and $10^{13} W/cm^{2}$). To overcome these limitations different techniques have been developed such as XPW, plasma mirrors and OP-CPA font ends.
In this work we present a high-repetition rate plasma mirror developed for the ELI-ALPS tested at the50 TW laser at L2A2 Lab at the USC (1J, 30 mJ, 35 fs, 10Hz, Ti:Sapph system) and the Sylos alignment beam at ELI-ALPS (30 mJ, 15 fs, 10Hz, OPCPA system). The PM works with a small incidence angle (< 4º) that allows us to use P-polarization through the experiment. A commercial AR (NBK-7, MgF2, R< 1.75% @ 800nm) substrate is ionized by the laser pulse to reflect the main part of the laser beam and improve the contrast below $10^{-9}$. As the target is destroyed after every shot, we rotate the substrate using a target composed by a rotational and a linear stages. This allow us to operate the PM with high stability with a repetition rate of 10 Hz for more than 14.000 continuous shots. We present measurents of the performance of the PM which show good stability in the pulse duration, the energy contrast, the reflectivity, beam pointing and Strehl ratio in two different laser systems.
