Abstract
Thin-foil targets were irradiated with high-power (), 10-ps pulses focused to intensities of and studied with -photon spectroscopy. Comparing the energy emitted in photons to target-heating calculations shows a laser-energy-coupling efficiency to hot electrons of . Time-resolved x-ray emission measurements suggest that laser energy is coupled to hot electrons over the entire duration of the incident laser drive. Comparison of the -photon emission data to previous data at similar laser intensities shows that is independent of laser-pulse duration from .
- Received 10 August 2009
DOI:https://doi.org/10.1103/PhysRevLett.105.235001
© 2010 The American Physical Society