Abstract
We show that the properties of the electron beam and bright x-rays produced by a laser wakefield accelerator can be predicted if the distance over which the laser self-focuses and compresses prior to self-injection is taken into account. A model based on oscillations of the beam inside a plasma bubble shows that performance is optimised when the plasma length is matched to the laser depletion length. With a 200~TW laser pulse this results in an x-ray beam with median photon energy of \unit[20]{keV}, $> 6\times 10^{8}$ photons above \unit[1]{keV} per shot and a peak brightness of $\unit[3 \times 10^{22}]{photons~s^{-1}mrad^{-2}mm^{-2} (0.1\% BW)^{-1}}$.
Highlights
We show that the properties of the electron beam and bright x rays produced by a laser wakefield accelerator can be predicted if the distance over which the laser self-focuses and compresses prior to self-injection is taken into account
One of the primary near-term uses of laser wakefield accelerators is the production of bright, femtosecond-duration pulses of broadband x rays [9,10], that are suitable for a range of applications [11]
We report on the experimental optimisation of the x rays generated by a laser wakefield accelerator driven by a 200 TW laser
Summary
We show that the properties of the electron beam and bright x rays produced by a laser wakefield accelerator can be predicted if the distance over which the laser self-focuses and compresses prior to self-injection is taken into account. Laser wakefield accelerators [1] have gathered increasing interest since it was first shown that they were capable of producing high-quality electron beams [2,3,4]. The data show that there is an optimum density for acceleration of ne ≈ 3.8 × 1018 cm−3 and that the x-ray signal is correlated with the electron beam energy.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
