0.1–10-keV x-ray-induced electron emissions from solids—Models and secondary electron measurements

Analytical models are presented describing the x-ray-excited emission of ’’no-loss’’ photoelectrons and Auger electrons and the energy distribution of emitted secondary electrons. The secondary electron energy distribution is given in terms of the electron kinetic energy EK, work function W, photon energy Eo, and mass photoionization coefficient μ (Eo), as proportional to Eoμ (Eo) EK(EK+W)−4. Techniques of electron spectral measurements utilizing uniform field preacceleration and limited acceptance angle spectrometers are discussed. Secondary electron energy distributions are measured at about 10−8 Torr from thick evaporated films of gold and aluminum at photon energies 277, 1487, and 8050 eV. The shapes of these distributions do not depend significantly upon photon energy. The full width at half-maximum (FWHM) of these distributions are 3.9, 6.7, and 4.4 eV for Au and ion-cleaned Au and Al photocathodes, respectively. The data agree well with the model predictions.