Hard X-ray sources from Self-Modulated Laser Wakefield Acceleration*

Laser-plasma-based accelerators are now able to provide the scientific community with novel high-energy light sources that are essential to study high-energy density matter, inertial confinement fusion, astrophysical systems, and fundamental plasma physics. Due to the transient and high-density properties of these systems, it is essential to develop light sources that are: in the hard x-ray energy range (0.01-1 MeV), directional, high-yield, low-divergence, and short-duration (ps and sub-ps). In this work we show that by using a Self-Modulated Laser Wakefield Accelerator (SM-LWFA) [1] it is possible to generate a broadband (0.01-1 MeV) hard x-ray source that satisfies the previous requirements. A series of experiments were conducted on the Titan laser at Lawrence Livermore National Laboratory where a 10 nC electron beam in the 10-400 MeV energy range was generated through SM-LWFA. The electrons generate x-rays via their betatron motion (few-30 keV) [2,3] and hard x-rays rays through inverse Compton scattering [4] (10-300 keV) and/or Bremsstrahlung [5] (up to 100 MeV). Due to its unique characteristics this source can be an important tool on large-scale international laser facilities opening up the prospect for many applications.

[1] Modena A. et al Nature 377 606–8 (1995)

[2] N. Lemos, et al, Plasma Phys. Control. Fusion 58, 034018 (2016)

[3] F. Albert, N. Lemos et al, Phys. Rev. Lett. 118, 134801 (2017)

[4] N. Lemos, F. Albert et al, in preparation for Phys. Rev. Lett.

[5] N. Lemos, F. Albert et al, Plasma Phys. Control. Fusion 60, 054008 (2018)