Radiative decays of unbound high-spin states in 24Mg (II)

Known negative-parity levels at 11.59(5-), 12.44 (7-), 13.06(5-), and 13.76(5-) MeV in 24Mg have been studied as resonances in the 20Ne(α, γ)24Mg reaction, and their radiative and α-particle decay widths deduced. The 12.44 MeV level is identified as the 7- member of a Kπ = 0- band by virtue of a strongly enhanced E2 γ-ray transition to the 10.03 MeV 5- level. The 13.06 MeV level exhibits a strongly enhanced γ-ray transition to a probable 3- level at 10.33 MeV, indicating the existence of a new negative-parity rotational band in 24Mg. Known 4+ levels at 12.05, 12.12, 12.16, 12.51 and 13.05 MeV have also been studied as 20Ne(α, γ)24Mg resonances in a search for the 4+ member of a proposed excited Kπ = 0+ band via an enhanced E2 transition to the 8.65 MeV 2+ level. No such transition was observed, but the 12.05 MeV level was identified as the second 4+ T = 1 level in 24Mg. In addition, γ-ray decay schemes and angular distributions provided the following information on the spins and parities of three sharp resonances near 14 MeV in 24Mg: 14.10, (2, 4)+; 14.146, 4+ (3-, 5-) and 14.32, 4+. © 1979.