The Alpha- and Gamma-Ray Spectra ofPu238

The alpha and gamma spectra of ${\mathrm{Pu}}^{238}$ have been studied with an alpha-particle spectrograph and gamma-ray scintillation and proportional counters. Alpha groups of 5.495 (72 percent), 5.452 (28 percent), and 5.352 Mev (0.09 percent) and electromagnetic radiations of 17 (13 percent), 43.8±0.5 (0.038 percent), 99±2 (0.008 percent), and 150±2 kev (0.001 percent) were observed. Spins and parities are assigned to the energy levels, and the results are evaluated with respect to the developing theory and systematics of complex alpha spectra and excited states of even-even nuclei.