HIGHER-ENERGY GAMMA RAYS IN THE DECAY OF NEPTUNIUM-239

Abstract

In the decay of neptunium-239 only two γ-rays with energies in excess of 335 kev have been detected. These have energies of 440 ± 10 and 490 ± 10 kev and intensities of 3.6 ± 0.9 × 10−5 and 2.0 ± 0.5 × 10−5 photons per disintegration respectively. A search at high resolution failed to reveal the associated conversion lines in the β-spectrum.