Artificial Radioactivity ofCr49

A radioactive isotope of half-life 41.9±0.3 minutes has been produced by alpha-particle bombardment of titanium and by fast neutron bombardment of chromium. Evidence presented shows that the activity should be assigned to ${\mathrm{Cr}}^{49}$. Absorption measurements indicate the presence of gamma-rays of energies 0.19 and 1.55 Mev. The end point of the positron spectrum is 1.45 Mev. The 33-minute activity in vanadium is assigned to ${\mathrm{V}}^{47}$.