THE NEW RADIOACTIVE ISOTOPES VANADIUM 46, MANGANESE 50, COBALT 54

Abstract

Three new positron activities assigned to V46 (0.40 sec.; Emax > 6.0 Mev.). Mn50 (0.28 sec.; Emax > 6.3 Mev.), and Co54 (0.18 sec.; Emax > 7.4 Mev.) have been induced by (p,n) reactions which take place in the McGill cyclotron at thresholds less than 12.5 Mev. The assignments are based on the thresholds and on the approximate ft values of the transitions.After a brief period of bombardment, controlled through the oscillator, the targets are shot back by a pneumatic extractor to a position of minimum magnetic field near the cyclotron where a suitably shielded anthracene counter system sends pulses to the main laboratory. Finally, the output of a counting-rate meter is displayed against time on an oscilloscope. This visual display reveals immediately new periods in decays, which are then photographed for later analysis.