Compact Spectroscopy of keV to MeV X-rays from a Laser Wakefield Accelerator
Abstract
We reconstruct spectra of secondary X-rays from a tunable 250-350 MeV laser wakefield electron accelerator from single-shot X-ray depth-energy measurements in a compact (7.5 7.5 15 cm), modular X-ray calorimeter made of alternating layers of absorbing materials and imaging plates. X-rays range from few-keV betatron to few-MeV inverse Compton to >100 MeV bremsstrahlung emission, and are characterized both individually and in mixtures. Geant4 simulations of energy deposition of single-energy X-rays in the stack generate an energy-vs-depth response matrix for a given stack configuration. An iterative reconstruction algorithm based on analytic models of betatron, inverse Compton and bremsstrahlung photon energy distributions then unfolds X-ray spectra, typically within a minute. We discuss uncertainties, limitations and extensions of both measurement and reconstruction methods.
Keywords
Cite
@article{arxiv.2103.01370,
title = {Compact Spectroscopy of keV to MeV X-rays from a Laser Wakefield Accelerator},
author = {A. Hannasch and A. Laso Garcia and M. LaBerge and R. Zgadzaj and A. Koehler and J. P. Couperus Cabadag and O. Zarini and T. Kurz and A. Ferrari and M. Molodtsova and L. Naumann and T. Cowan and U. Schramm and A. Irman and M. C. Downer},
journal= {arXiv preprint arXiv:2103.01370},
year = {2021}
}