A new technique for measuring positron impact direct ionisation Joshua R. Machacek, Tamara J. Babij, Daniel J. Murtagh, Steven J. Buckman and James P. Sullivan Eur. Phys. J. D, 71 12 (2017) 328 Published online: 14 December 2017 DOI: 10.1140/epjd/e2017-80533-7