Gamma-neutron activation experiments using laser wakefield accelerators*

Gamma-neutron activation experiments have been performed with relativistic electron beams produced by a laser wakefield accelerator. The electron beams were produced by tightly focusing ~spot diameter '6 mm) a high power ~up to 10 TW!, ultra-short (>50 fs) laser beam from a high repetition rate ~10 Hz! Ti:sapphire ~0.8 mm! laser system, onto a high density (.10 cm) pulsed gasjet of length '1.5 mm. Nuclear activation measurements in lead and copper targets indicate the production of electrons with energy in excess of 25 MeV. This result was confirmed by electron distribution measurements using a bending magnet spectrometer. Measured g-ray and neutron yields are also found to be in reasonable agreement with simulations using a Monte Carlo transport code. © 2001 American Institute of Physics. @DOI: 10.1063/1.1352617#