Angular velocity spread of relativistic photoelectrons induced by excimer laser irradiation

Abstract
The angular velocity spread of relativistic photoelectrons induced by a pulsed excimer laser was measured. The energy, the current density, and the pulse duration of the accelerated photoelectron were 0.34 MeV, 0.5 A/cm2, and 20 ns, respectively. (The method of measurement is based on measuring Larmor radius which corresponds to the transverse component of the electron velocity.) The angular velocity spread β was found to be less than 8×103, which means that the energy component due to β was as small as ≲17 eV.