Positron annihilation spectroscopy on a beam of positrons the LEPTA facility E.V. Ahmanova, M.K. Eseev, A.G. Kobets, I.N. Meshkov, O.S. Orlov, A.A. Sidorin, K. Siemek and P. Horodek EPJ Web Conf., 132 (2017) 03014 Published online: 13 December 2016 DOI: 10.1051/epjconf/201713203014