A new technique for measuring positron impact direct ionisationJoshua R. Machacek, Tamara J. Babij, Daniel J. Murtagh, Steven J. Buckman and James P. SullivanEur. Phys. J. D, 71 12 (2017) 328DOI: https://doi.org/10.1140/epjd/e2017-80533-7