Pulsed laser-plasma gamma radiation source for radiography

Abstract

We have performed experiments on the generation of relativistic electron beams in helium gas jets (electron density ∼1020 cm−3) using a femtosecond Ti : sapphire laser. Electron beams with a total charge of 0.2−0.5 nC, a maximum electron energy of up to 60 MeV, and a divergence of up to 300 mrad are recorded. The generated electron beams are converted into bremsstrahlung X-rays using a Ta plate 2 mm thick. The average dose of bremsstrahlung radiation in the air at a distance of 1 m from the source was 5.4 ±1.7 mrad per pulse. The emitting region size measured by the blurriness of the X-ray image is about 650 μm (FWHM).