Abstract
An accurate determination of the energy of the sixth excited state in has been carried out because of the proximity of this level to the proton binding energy and the resulting possibility of its importance in the stellar formation of . Gamma rays from this state occurring in the reaction at MeV were measured by means of a Ge(Li) detector at 90° to the beam. The transition leading to the (5241.3±0.5)-keV level of is found to have an energy of 2034.7±0.3 keV. Thus the level in question has an energy of 7276.0±0.6 keV, which is 16.8±1.3 keV below the proton binding energy of 7292.8±1.2 keV. From a measurement at 0° to the beam the 0°-90° Doppler shift of the 2035-keV gamma ray is found to be 2.3±0.4 keV. For a very short lifetime the expected Doppler shift is 14.4±1.3 keV. The observed shift corresponds to a mean lifetime of (1.25±0.3)× sec for the 7276-keV state of .
- Received 18 July 1966
DOI:https://doi.org/10.1103/PhysRev.152.914
©1966 American Physical Society