Hot ion generation from nanostructured surfaces under intense femtosecond laser irradiation

Abstract

Studies of ion emission from nanostructured metallic surfaces excited by intense (0.5-6.3× 1016 W cm-2) 50 fs laser demonstrate that "hotter" electrons need not to give rise hotter ions, contrary to conventional expectation. Such surfaces produce twice as many ions as planar surfaces in the moderate energy regime (16-75 keV), but their yield in the higher energy range (75-2000 keV) is substantially lower. Surface modulations also influence ion beam divergence. © 2007 American Institute of Physics.