Real-time monitoring via second-harmonic interferometry of a flow gas cell for laser wakefield acceleration
Authors: Brandi F., Giammanco F., Conti F., Sylla F., Lambert G., Gizzi LA.
Autors Affiliation: CNR, ILIL, INO, Via Moruzzi 1, I-56124 Pisa, Italy; IIT, Via Morego 30, I-16163 Genoa, Italy; Univ Pisa, Dipartimento Fis, Largo B Pontecorvo 3, I-56127 Pisa, Italy; Plasma Diagnost & Technol Ltd, Via Matteucci 38-D, I-56124 Pisa, Italy; SourceLAB SAS, 86 Rue Paris, F-91400 Orsay, France Univ Paris Saclay, Ecole Polytech, CNRS, LOA,ENSTA ParisTech, 828 Bd Marechaux, F-91762 Palaiseau, France
Abstract: The use of a gas cell as a target for laser wakefield acceleration (LWFA) offers the possibility to obtain stable and manageable laser-plasma interaction process, a mandatory condition for practical applications of this emerging technique, especially in multi-stage accelerators. In order to obtain full control of the gas particle number density in the interaction region, thus allowing for a long term stable and manageable LWFA, real-time monitoring is necessary. In fact, the ideal gas law cannot be used to estimate the particle density inside the flow cell based on the preset backing pressure and the room temperature because the gas flow depends on several factors like tubing, regulators, and valves in the gas supply system, as well as vacuum chamber volume and vacuum pump speed/throughput. Here, second-harmonic interferometry is applied to measure the particle number density inside a flow gas cell designed for LWFA. The results demonstrate that real-time monitoring is achieved and that using low backing pressure gas (<1 bar) and different cell orifice diameters (<2 mm) it is possible to finely tune the number density up to the 10(19) cm(-3) range well suited for LWFA. Published by AIP Publishing. Journal/Review: REVIEW OF SCIENTIFIC INSTRUMENTS
Volume: 87 (8) Pages from: 086103-1 to: 086103-3
KeyWords: PLASMA ACCELERATORS; RANGEDOI: 10.1063/1.4960399Citations: 10data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-10-17References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here