Figure 4
Continuous spectra of (space-charge accelerated) electrons due to the interaction of a femtosecond-laser beam at λ = 800 nm with Cu(110) and Cu(111) surfaces. Spectra have been taken at grazing angles of Θg = 16° and 11° with respect to the surface, at laser repetition frequencies of 6034 and 3017 Hz and at mean laser powers 〈P〉 of 500 mW (82 µJ per pulse), 200 mW (33 µJ per pulse) and 50 mW (17 µJ per pulse). |