Development of a Nomarski-type multi-frame interferometer as a time and space resolving diagnostics for the free electron density of laser-generated plasma

M Börner; J Fils; A Frank; A Blažević; T Hessling; A Pelka; G Schaumann; A Schökel; D Schumacher; M M Basko; J Maruhn; An Tauschwitz; M Roth

doi:10.1063/1.3701366

Development of a Nomarski-type multi-frame interferometer as a time and space resolving diagnostics for the free electron density of laser-generated plasma

Rev Sci Instrum. 2012 Apr;83(4):043501. doi: 10.1063/1.3701366.

Authors

M Börner¹, J Fils, A Frank, A Blažević, T Hessling, A Pelka, G Schaumann, A Schökel, D Schumacher, M M Basko, J Maruhn, An Tauschwitz, M Roth

Affiliation

¹ Institut für Kernphysik, Technische Universität Darmstadt, Schlossgartenstrasse 9, 64289 Darmstadt, Germany.

PMID: 22559530
DOI: 10.1063/1.3701366

Abstract

This article reports on the development and set-up of a Nomarski-type multi-frame interferometer as a time and space resolving diagnostics of the free electron density in laser-generated plasma. The interferometer allows the recording of a series of 4 images within 6 ns of a single laser-plasma interaction. For the setup presented here, the minimal accessible free electron density is 5 × 10(18) cm(-3), the maximal one is 2 × 10(20) cm(-3). Furthermore, it provides a resolution of the electron density in space of 50 μm and in time of 0.5 ns for one image with a customizable magnification in space for each of the 4 images. The electron density was evaluated from the interferograms using an Abel inversion algorithm. The functionality of the system was proven during first experiments and the experimental results are presented and discussed. A ray tracing procedure was realized to verify the interferometry pictures taken. In particular, the experimental results are compared to simulations and show excellent agreement, providing a conclusive picture of the evolution of the electron density distribution.