”
. In 1930, with Professor Millikan, he began his cosmic-ray studies which led in 1932 to the discovery of the positron. He has studied the energy distribution of cosmic-ray particles and the energy loss of very high speed electrons in traversing matter. In 1933 he and Dr. Neddermeyer obtained the first direct proof that gamma rays from ThC” generate positrons in their passage through material substances. “
https://www.nobelprize.org/prizes/physics/1936/anderson/biographical/
REFERENCES:
https://timeline.web.cern.ch/carl-anderson-discovers-positron