THE DECAY MODES OF THE 9.17-Mev EXCITED STATE IN N$sup 1$$sup 4$
A search was made for the gamma rays and gamma -cascade transition resulting from the decay of the 9.17-Mev excited state in N/sup 14/ using the reaction C/sup 13/(p, gamma )N/sup 14/ at the 1.75-Mev resonance. The main purpose of the investigation was to gain information about the " missing" (2,0) and (2,1) levels arising from the p-/sup 2/ configuration in mass 14 by obtaining a detailed decay scheme for the 9.17-Mev state. For that purpose, three-crystal pair spectrometer techniques were applied to search for gamma rays too weak to be detected by -single spectra measurements in the presence of the strong 9.17 Mev -- ground-state transition. In addition to the previously reported transitions from the 9.17-Mev state to the ground state and the 6.44-Mev excited state, a transition was observed to the 7.03-Mev excited state. Furthermore, three-crystal pair spectra measurements and coincidence measurements indicate a transition from the 9.l7-Mev excited state to the (presumably) odd-parity T=0 state at 5.83 Mev and possibly to the 5.69- and 5.10Mev states. Upper limits were placed on the transitions to the 5.69- and 5.10-Mev states. Observation of gamma rays with energies of 1.64 and 2.49 Mev in three-crystal pair spectra measurements and in several coincidence Measurements gave evidence that the 6.44- Mev excited state branches to the 3.95-Mev (1,0) state. To obtain anisotropies and intensities relative to the 9.17 Mev -ground-state transition for the gamma rays observed, threecrystal pair spectra were taken at 0 to 90 deg relative to the proton beam. The results of these measurements (combined with results about the 9.17 -- 6.44 Mev -ground-state transition published recently) lead to spin assignments of J = 2 to the 9.17-Mev level and of J = 3 to the 6.44-Mev level. Furthermore, they lead to a spin assignment of J = 2 to the 7.03-Mev excited state in N/sup 14/. The latter assignment and comparison of the strength of the 9.l7 -- 7.03-Mev transition with results of calculations obtained by Warburton and Pinkston suggest that the 7.03Mev excited state arises from the p-/sup 2/ configuration as (2,O) level and that the 9.17-Mev level at least in part arises from p-/sup 2/ as (2,1) level. Comparison of the dipolequadrupole mixture (0.13 < delta <3.5) in the 7.03 Mev -ground-state transition, which was determined from the Measured anisotropy of this transition, with theoretical results of Warburton and Pinkston agrees with this conclusion. (auth)
- Research Organization:
- Universitat, Freiburg i.B.
- NSA Number:
- NSA-15-002186
- OSTI ID:
- 4128763
- Journal Information:
- Nuclear Phys., Vol. Vol: 19; Other Information: Orig. Receipt Date: 31-DEC-61
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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