Energy Levels ofFe56

Abstract

The energies and relative intensities of the gamma radiations following the decay of $^{56}\mathrm{Co}$ to $^{56}\mathrm{Fe}$ have been measured using a 3-mm depletion-depth lithium-drifted germanium detector. Gamma rays of the following energies were observed (relative intensities in parentheses): 846.5(100.0), 1038.1(12.4), 1238.6(71.2), 1359.9(3.8), 1770.8(15.6), 2015.6(3.8), 2034.7(7.8), 2598.9(16.0), 3009.5(1.9), 3202.3(2.9), 3254.0(5.8), 3273.6(1.2), 3452.6(0.7), and 3548.3(0.2) keV. A decay scheme was constructed with levels at 846.5(${2}^{+}$), 2085.1(${4}^{+}$), 3123.2(${4}^{+}$), 3445.2(${3}^{+}$), 3856.0(${3}^{+}$), 4048.8, 4100.6, 4120.0, 4299.1, and 4394.8 keV. No evidence was found for doublet energy levels at 3123.2 and 3445.2 keV as indicated in recent particle-scattering experiments, thus supporting spin assignments of ${1}^{+}$ for the unobserved members. The energies of several new gamma-ray standards were established. Energies and relative intensities of gamma-ray transitions following the decay of $^{58}\mathrm{Co}$ to $^{58}\mathrm{Fe}$ were also measured and found to be 810.2(100.0), 863.8(0.64), and 1674.9(0.46) keV.