Low-lying levels of 57Mn from the 54Cr(α,p) reaction
Abstract
Proton energy spectra from the 54Cr(α,p)57Mn reaction at 15, 21, and 24 MeV and at several angles have been measured with the 100-cm broad-range spectrograph. Both NaI(Tl) and Ge(Li) detectors have been used to study γ rays, in coincidence with protons in a particle detector, from the same reaction. From the spectrograph measurements, the ground-state Q value is found to be -4308 +/- 8 keV. Excited levels have been found at 84.1 +/- 1.0, 851.1 +/- 1.0, 1059.2 +/- 2.0, 1073.8 +/- 2.0, 1227.1 +/- 1.0, 1376.5 +/- 1.3, 2188.2 +/- 1.1, and 2234.3 +/- 1.7 keV. Ten γ-ray transitions have been observed. From particle-γ coincidence and angular-correlation measurements the spins of some levels can be limited as follows: 84 keV, 3/2-7/2; 851 keV, 3/2 or 5/2; 1059 keV, 1/2-5/2. Probable spin assignments for these three levels suggested on the basis of cross-section and relative transition-strength considerations are (7/2), (3/2), and (1/2), respectively. Other tentative spin assignments, and the comparison of 57Mn with other odd Mn isotopes, are discussed. NUCLEAR REACTIONS 54Cr(α,p), E=15-24 MeV; measured Q, levels. 54Cr(α,p γ), E=11.0-11.5 MeV; measured p γ-coin, p γ(θ), γ branching. 57Mn levels deduced J, δ. Enriched target.
- Publication:
-
Physical Review C
- Pub Date:
- January 1976
- DOI:
- 10.1103/PhysRevC.13.118
- Bibcode:
- 1976PhRvC..13..118M