A monoenergetic photon beam of variable energy produced by the annihilation of positrons in flight.
Photons monochromatiques d'énergie variable obtenus par annihilation en vol de positons
J. Phys. Radium, 21 10 (1960) 755-756
DOI: https://doi.org/10.1051/jphysrad:019600021010075500