Extreme field gradients intrinsic to relativistic laser plasma interactions enable compact MeV proton accelerators with unique bunch characteristics. Yet, direct control of the proton beam profile is usually not possible. So far, only complex micro-engineering of the relativistic plasma accelerator itself and limited adoption of conventional beam optics provided access to global beam parameters that define propagation.
We present a novel, counter-intuitive all-optical approach to imprint detailed spatial information from the driving laser pulse to the proton bunch.
The concept was motivated by an effect initially observed in an experiment dedicated to laser-driven proton acceleration from a renewable micrometer sized cryogenic Hydrogen jet target at the 150 TW Draco laser at HZDR. A compact, recollimating single plasma mirror was used to enhance the temporal laser contrast, which could be monitored on a single-shot base by means of self-referenced spectral interferometry with extended time excursion (SRSI-ETE) at unprecedented dynamic and temporal range. Unexpectedly, the accelerated proton beam profile showed in this experiment prominent features of the collimated laser beam, such as the shadow of obstacles inserted deliberately in the beam.
In a series of further experiments, the spatial profile of the energetic proton bunch was found to exhibit identical features as the fraction of the laser pulse passing around a target of limited size. The formation of quasi-static electric fields in the beam path by ionization of residual gas in the experimental chamber results in asynchronous information transfer between the laser pulse and the naturally delayed proton bunch.
Such information transfer between the laser pulse and the naturally delayed proton bunch is attributed to the formation of quasi-static electric fields in the beam path by ionization of residual gas. Essentially acting as a programmable memory, these fields provide access to a new level of proton beam manipulation.
Simulations of experiments at modern light sources, such as optical laser laboratories, synchrotrons, and
free electron lasers, become increasingly important for the successful preparation, execution, and analysis of these
experiments investigating ever more complex physical systems, e.g. biomolecules, complex materials, and ultra–short
lived states of matter at extreme conditions. We have implemented a platform for complete start–to–end simulations
of various types of photon science experiments, tracking the radiation from the source through the beam transport
optics to the sample or target under investigation, its interaction with and scattering from the sample, and registration
in a photon detector. This tool allows researchers and facility operators to simulate their experiments and instruments
under real life conditions, identify promising and unattainable regions of the parameter space and ultimately make
better use of valuable beamtime. In this paper, we present an overview about status and future development of the
simulation platform and discuss three applications: 1.) Single–particle imaging of biomolecules using x–ray free
electron lasers and optimization of x–ray pulse properties, 2.) x–ray scattering diagnostics of hot dense plasmas in
high power laser–matter interaction and identification of plasma instabilities, and 3.) x–ray absorption spectroscopy
in warm dense matter created by high energy laser–matter interaction and pulse shape optimization for low–isentrope