Gamma decay of high spin states inMg25above 6.1 MeV

The structure of25Mg

“…The 7-decay of levels between 6.! On the other hand all the levels observed below 10 MeV excitation energy which are given in [9] are also contained in our work (Fig. They are superseded now because weaker branches have become accessible to observation and also because the early data were affected by a calibration error in the high-energy part of the y-ray spectra.…”

“…The quantum numbers of several high-spin states can be obtained or restricted by combining the results of the present work with those of the concurrent study [9] of 25Mg with the 12 C(14N, p V) reaction.…”

“…The low-lying states with I < 9/2 reflect the spectrum of a prolate deformed system [14]. At higher spin the experimental situation is still rather confusing [9,12,13]. At higher spin the experimental situation is still rather confusing [9,12,13].…”

“…and 8.6 MeV excitation energy had been investigated in early work with the 24Mg(d, PT) reaction E10] and these data have provided the only source of information on the ~-decay of higher-excited states over a period of 15 years. 4), except for a 7685 keV level which, according to [9], decays exlcusively to the 4060 keV state. As a consequence, excitation energies of levels above 6 MeV as quoted in [10] 2.…”

“…A new empirical s-d shell Hamiltonian (the USD Hamiltonian) has been introduced which has a (18/A) ~ mass dependence of the interaction matrix elements. Most recently, however, y-decay modes of several highly-excited high-spin states in 25Mg have been observed by virtue of the 12C(a4N, py) reaction [9]. The potential of the shell model in describing the A=25, T= 1/2 system has been established at an early stage by Cole et al [7,8] who used the Preedom-Wildenthal Hamiltonian, a precursor of the particle Hamiltonian.…”