Binary reaction decays fromMg24+C12

Abstract

Charged-particle and γ decays in 24 Mg * are investigated for excitation energies where quasimolecular resonances appear in 12 C + 12 C collisions. Various theoretical predictions for the occurrence of superdeformed and hyperdeformed bands associated with resonance structures with low spin are discussed within the measured 24 Mg * excitation energy region. The inverse kinematics reaction 24 Mg + 12 C is studied at E lab ( 24 Mg) = 130 MeV, an energy that enables the population of 24 Mg states decaying into 12 C + 12 C resonant breakup states. Exclusive data were collected with the Binary Reaction Spectrometer in coincidence with Euroball IV installed at the Vivitron tandem facility at Strasbourg. Specific structures with large deformation were selectively populated in binary reactions, and their associated γ decays studied. Coincident events associated with inelastic and α-transfer channels have been selected by choosing the excitation energy or the entry point via the two-body Q values. The analysis of the binary reaction channels is presented with a particular emphasis on 24 Mg-γ, 20 Ne-γ , and 16 O-γ coincidences. New information (spin and branching ratios) is deduced on high-energy states in 24 Mg and 16 O, respectively.

Recent Experimental Results on Nuclear Cluster Physics

“…Ternary clusterizations are also predicted theoretically, but were not found experimentally in 36 Ar so far [8,58]. On the other hand, ternary fission of 56 Ni, related to its HD shapes, was identified from out-of-plane angular correlations measured in the 32 S+ 24 Mg reaction with the Binary Reaction Spectrometer at the Vivitron Tandem facility [67].…”

“…Highly deformed shapes and SD rotational bands have been discovered in several light α-like nuclei, such as 36 Ar and 40 Ca by using γ-ray spectroscopy techniques [57,59]. In particular, the extremely deformed rotational SD band in 36 Ar [57] is comparable in shape to the quasimolecular bands observed in both 12 C+ 24 Mg and 16 O+ 20 Ne reactions [8,58,64].…”

“…Furthermore, the structure of possible octupole-unstable 3:1 nuclear shapes (hyperdeformation (HD) with β 2 ≈ 1.0) has also been discussed for actinide nuclei in terms of clustering phenomena [8]. Typical examples for the link between quasimolecular bands and extremely deformed (SD/HD) shapes can be found in the literature for A = 20 − 60 α-conjugate N =Z nuclei [8,18,36,52,54,55,56,57,58,59,60,61,62,63,64,65,66,67]. Highly deformed shapes and SD rotational bands have been discovered in several light α-like nuclei, such as 36 Ar and 40 Ca by using γ-ray spectroscopy techniques [57,59].…”

Clustering in Stable and Exotic Light Nuclei

“…There is a renewed interest in the spectroscopy of the 16 O nucleus at high excitation energy [96,99]. Exclusive data were collected on 16 O in the inverse kinematics reaction 24 Mg+ 12 C studied at E lab ( 24 Mg) = 130 MeV with the BRS in coincidence with the Euroball IV installed at the Vivitron facility [96,99]. From the α-transfer reactions (both direct transfer and deep-inelastic orbiting collisions [123]), new information has been deduced on branching ratios of the decay of the 3 + state of 16 O at 11.085 MeV ± 3 keV.…”

“…The high-energy level scheme of 16 O shown in Ref. [96,99] indicated that this state does not α-decay because of its non-natural parity (in contrast to the two neighbouring 4 + states at 10.36 MeV and 11.10 MeV), but it γ decays to the 2 + state at 6.92 MeV (54.6 ± 2 %) and to the 3 − state at 6.13 MeV (45.4%). By considering all the four possible transition types of the decay of the 3 + state (i.e.…”