Laser‑driven low energy electron beams for single‑shot ultra‑fast probing of meso‑scale materials and warm dense matter

Laser wakefield acceleration has proven to be an excellent source of electrons and X‑rays suitable
for ultra‑fast probing of matter. These novel beams have demonstrated unprecedented spatial and
temporal resolution allowing for new discoveries in material science and plasma physics. In particular,
the study of dynamic processes such as non‑thermal melt and lattice changes on femtosecond
time‑scales have paved a way to completely new scientific horizons. Here, we demonstrate the first
single‑shot electron radiography measurement using an femtosecond electron source based on the
downramp‑density gradient laser‑wakefield‑acceleration with the use of a compact Ti:sapphire laser. A
quasi‑monoenergetic electron beam with mean energy of 1.9 ± 0.4 MeV and charge 77 ± 47 pC per shot
was generated by the laser incident onto a gas target and collimated using a two ring‑magnet beam
path. High quality electron radiography of solid objects with spatial resolution better than 150 μm was
demonstrated. Further developments of this scheme have the potential to obtain single‑shot ultrafast
electron diffraction from dynamic lattices. This scheme poses a great promise for smaller scale
university laboratories and facilities for efficient single‑shot probing of warm dense matter, medical
imaging and the study of dynamic processes in matter with broad application to inertial confinement
fusion and meso‑scale materials (mg g/cm2).