Application of Nomarski interference system in supersonic gas-jet target diagnosis

Qiushi Liu,Baozhen Zhao,Chong Lv,Mingjiang Ma,Xiaohua Zhang,Chuangye He,Fulong Liu,Xiaofeng Xi,Bing Guo,Xianghao Meng,Zhao Wang,Baoxian Tian

doi:10.1063/5.0027317

Abstract

Supersonic gas-jet target performs an important role in laser wakefield acceleration, and its density diagnosis is a significant part of target characteristic study. In this paper, a Mach–Zehnder and Nomarski interference system is set up and used for gas-jet target density diagnosis. We have investigated and compared the performance of the Mach–Zehnder part and Nomarski part. The feasibility of the Nomarski interferometer with vertical fringes has been verified. Moreover, it shows better stability and has a more compact structure, beneficial for obtaining more accurate and effective target density characterization in laser wakefield acceleration.

Highlights

The continuous and rapid development of ultra-short pulse laser provides unprecedented experimental means and extreme physical conditions
Supersonic gas-jet target performs an important role in laser wakefield acceleration, and its density diagnosis is a significant part of target characteristic study
The Nomarski interferometer with horizontal fringes has been usually used for plasma density diagnosis in laser wakefield acceleration (LWFA).35–41

Summary

INTRODUCTION

The continuous and rapid development of ultra-short pulse laser provides unprecedented experimental means and extreme physical conditions. Supersonic gas-jet targets can provide a specific gas density profile, control the electron injection, and be applied to high repetition rate experiments In this way, the beam quality is effectively improved.. In the overlapping area of two beams, interference fringes can be obtained This kind of interferometer has the characteristics of small size, equal optical path, and temporal–spatial coherence. For the common horizontal fringe type, two images of the gas-jet will overlap in the fringe area, as shown, affecting the diagnosis accuracy of the target density profile. To solve this problem, the Nomarski system with vertical fringes is considerable. It might be beneficial to supersonic gas-jet target diagnosis in LWFA experiments

EXPERIMENTAL SETUP

ANALYSIS

AND DISCUSSION

CONCLUSION