Suppression of thermal nanoplasma emission in clusters strongly ionized by hard x-rays

Abstract Using electron and ion spectroscopy, we studied the nuclear dynamics in ∼50 000-atom large krypton clusters, following excitation with an intense hard x-ray pulse. Beyond single pulse experiment, also present results of a time-resolved, pump–near-infrared probe measurement that allows one to learn about time evolution system. After core ionization atoms by photons, trapped Auger secondary electrons form nanoplasma which ions are embedded, according already published scenario. While data show expected features, emission spectra miss pump–probe delay-dependent enhancement except for slight energy range below 2 eV. Theoretical simulations help reveal that, due deep trapping potential during long expansion accompanied electron–ion recombination, thermal from transient becomes quenched.