Electron refluxing and K-shell line emission from Ti foils irradiated with subpicosecond laser pulses at 527 nm.

ABSTRACT

We present data on emission of K-shell radiation from Ti foils irradiated with subpicosecond pulses of second harmonic radiation (527 nm) from the TARANIS laser system at intensities of up to 10(18) W cm(-2). The data are used to demonstrate that a resonance absorption type mechanism is responsible for absorption of the laser light and to estimate fast electron temperatures of 30-60 keV that are in broad agreement with expectation from models of absorption for a steep density gradient. Data taken with resin-backed targets are used to demonstrate clear evidence of electron refluxing even at the modest fast electron temperatures inferred.