Energy systematics of low-lying Nilsson levels in odd-mass einsteinium isotopes

Abstract

The decay of odd-mass mendelevium isotopes ( A = 247-255) has been studied by means of α-γ spectroscopy. Strong evidence for a small α branch in the decay of 253Md was found. γ lines in coincidence with α-decays of 247, 249, 251, 253Md have been observed for the first time. Levels in the einsteinium daughter nuclei were assigned on the basis of α-γ coincidence measurements. An energy systematics of the 7/2-[514] Nilsson level could be established, showing a correlation with the deformation parameter β2 of the corresponding nuclei. The results are compared with theoretical predictions.