# Laser-Plasma Accelerator Workshop 2019

May 5 – 10, 2019
MedILS
Europe/Berlin timezone

## Quantitative reconstruction of wakefield electron density distribution

Not scheduled
20m
MedILS

#### MedILS

Meštrovićevo šetalište 45 HR – 21000 Split Republic of Croatia
Poster Contribution

### Speaker

Mr Moritz Foerster (Ludwig-Maximilians-Universität München)

### Description

Few-cycle shadowgraphy is a common tool to qualitatively investigate the longitudinal and transverse structure of laser generated wakefields. However the measured intensity distribution provides hardly any information about the wake amplitude since the wakefield itself is a pure phase object and the measured intensity distribution is a function of the imaging plane. Commonly this plane is not precisely known due to the pointing jitter of the driver laser. One possible approach to investigate the phase object constituted by the electron distribution inside the wake is to image multiple planes around the wakefield. From these multiple intensity distributions it is possible to reconstruct the phase that defines the propagation between the imaged planes and therefore represents the original phase object.
We report on the successful reconstruction of the wakefield phase and subsequent extraction of the plasma refractive index. From that the electron density along the wakefield axis is calculated.
We experimentally observe wakefields in He-gasjets driven by a 100TW-class laser. The gas density is in the range of $5\cdot10^{18} cm^{-3}$. Assuming radial symmetry we find linear plasma wakes with a modulation depth comparable to that expected from theory and simulations.

Working group Diagnostics

### Primary author

Mr Moritz Foerster (Ludwig-Maximilians-Universität München)

### Co-authors

Hao Ding (LMU Munich) Andreas Döpp (LMU Munich) Max F. Gilljohann (Ludwig-Maximilians-Universität München) Prof. Stefan Karsch T. Heinemann (Deutsches Elektronen-Synchrotron DESY; Scottish Universities Physics Alliance, Department of Physics, University of Strathclyde) Thomas Kurz (HZDR) arie irman (HZDR) Mrs Susanne Schöbel (HZDR) Pablo San Miguel (Ecole Polytechnique) S. Corde (LOA, ENSTA ParisTech, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris)

### Presentation materials

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