MONTE-CARLO SIMULATION OF THE PRODUCTION OF CHARGE-CARRIERS IN NACL-CRYSTALS BY XUV IRRADIATION

A Monte Carlo simulation of the number as well as energy and spatial distribution of the electron-hole pairs created in NaCl crystals by irradiation with photons of 20 to 250 eV is carried out by using a simplified band scheme and the random-k approximation. It is shown that the low-energy parts of the carrier bands are populated preferentially. The computed mean pair-creation energy is in reasonable agreement with the experimental value (13. 4 to 16. 7 eV) if the inelastic electron-electron scattering threshold energy is chosen in the interval 1. 2 to 1. 5 E//g (E//g is the band-gap energy). The mean distance of the electron-hole pair creation events from the photon absorption site is 50 to 60 A.