Electron impact fragmentation of thymine: partial ionization cross sections for positive fragments Peter J.M. van der Burgt, Francis Mahon, Gerard Barrett and Marcin L. Gradziel Eur. Phys. J. D, 68 6 (2014) 151 Published online: 23 June 2014 DOI: 10.1140/epjd/e2014-40699-0