In-flight annihilation correction for 511 keV photon spectrometry G.F. Steyn, S.G. Dolley, F. Szelecsényi, Z. Kovács, N.P. van der Meulen and C. Vermeulen EPJ Web Conf., 146 (2017) 08010 Published online: 13 September 2017 DOI: 10.1051/epjconf/201714608010