Experimental observation of the ion energy spectra of Al, Co, and Cu laser produced plasmas Jon Imanol Apiñaniz, Alvaro Peralta Conde and Roberto Martínez Perez de Mendiola Eur. Phys. J. D, 69 12 (2015) 265 Published online: 03 December 2015 DOI: 10.1140/epjd/e2015-60109-5