Energetic electrons and x-ray photons from multiterawatt Ti : sapphire lasers

The energy distribution and yield of electrons and hard x-ray photons were investigated by irradiating tungsten and tantalum targets with similar to 3 0 fs pulses in the intensity range 10(18)-10(19) W cm(-2) by using the Labo ratoire d'Optique Appliquee (LOA) as well as the Max Born Institut (MBI) mu ltiterawatt Ti:sapphire lasers, For the measurement of the hard x-ray emiss ion in the energy range from 15 keV to 700 keV at the LOA a 9-channel spect rometer of calibrated thermoluminescence detectors (TLD) was used. The scal ing of the hard x-rays was studied by varying the incident laser energy wit hin one order of magnitude and the pulsewidth by a factor of 5. The hot ele ctron output was investigated in the range 300 keV-1 MeV with the new MBI T i: sapphire laser by using a time-of-flight spectrometer. The results indic ate a sensitive interplay between the temporal laser shape and laser intens ity.