Hot ion generation from nanostructured surfaces under intense,   femtosecond irradiation
  We present the effect of a nanostructured surface on the emission of ions and electrons from intense (5-36 Petwatt per sq.cm) femtosecond laser produced plasmas. Electrons from optically polished copper targets coated with copper nanoparticles (CuNP) are observed to be hotter than those from uncoated polished targets. A nearly two-fold enhancement is observed for ions in the range 14-74 keV, while ion yield decreases by a factor of 2 in the 74-2000 keV range. The total ion yields measured using a large area Faraday cup are more from CuNP targets than those from polished Cu targets, indicating increased ion beam divergence due to surface modulations. 
S. Bagchi, P. Prem Kiran, M.K. Bhuyan, S. Bose, P. Ayyub, M.   Krishnamurthy and G. Ravindra Kumar