An investigation of refractive effects in heavy-ion scattering is continued. For the elastic scattering of 16 O nuclei on a 13 C target at E ( 16 O) = 132 MeV, the differential cross sections are measured for the first time in addition to previous measurements for targets from the carbon isotopes 12 C and 14 C. Airy structures that are similar for all isotopes and which have close cross sections are observed and are found to be consistent with the energy systematics of Airy minima that were obtained previously. The volume integrals of the real and imaginary parts of the optical potentials found in the present study are nearly identical for all of the isotopes considered here and are also in good agreement with the systematics obtained previously.

The observation of nuclear rainbow phenomenon in some light nuclei collisions provides unique possibility to study nucleus-nucleus interactions at small distances. The valuable information on nuclear potentials of light heavy ions was obtained by investigation of 16O+16O and 12C+12C elastic scattering (see for references [1]). However, due to the fact that these systems are symmetric the meaningful angular distributions are limited by 90°. The neighbor asymmetrical combination 16O+12C seems more suitable from this point of view for studies in the energy region 10–20 MeV×A. We undertook systematic study of elastic scattering in this system at several 16O energies between 130 and 260 MeV [2, 3]. Well-developed rainbow patterns including the supernumerary Airy structures were observed. The potential parameters both from phenomenological (WS1) or folding calculations connected smoothly the results at higher [4] and lower [5] energies.

The Science and Culture Series — Advanced Scientific CultureNucleus–Nucleus Collisions, pp. 409-412 (2001) No AccessSTUDY OF CLUSTER EMISSION BARRIER IN 12C + 208PB ELASTIC SCATTERING AND POSSIBLE OBSERVATION OF QUASIMOLECULAR CONFIGURATIONA.A. OGLOBLIN, K.P. ARTEMOV, YU.A. GLUKHOV, A.S. DEM'YANOVA, V.V. PARAMONOV, M.V. ROZKOV, V.P. RUDAKOV, and S.A. GONCHAROVA.A. OGLOBLINKurchatov Institute, Mosco, K.P. ARTEMOVKurchatov Institute, Mosco, YU.A. GLUKHOVKurchatov Institute, Mosco, A.S. DEM'YANOVAKurchatov Institute, Mosco, V.V. PARAMONOVKurchatov Institute, Mosco, M.V. ROZKOVKurchatov Institute, Mosco, V.P. RUDAKOVKurchatov Institute, Mosco, and S.A. GONCHAROVSkobltsyn Institute of Nuclear Physics, Moscohttps://doi.org/10.1142/9789812810939_0064Cited by:0 PreviousNext AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail Abstract: No abstract received. FiguresReferencesRelatedDetails Nucleus–Nucleus CollisionsMetrics History PDF download

Angular correlation functions are measured for the d alpha system in the reaction S-32(Li-6, d)Ar-36*(alpha)S-32 induced by 22- and 38-MeV Li-6 ions. It is found that, in the Ar-36 nucleus, there exist 5(-), 6(+), 7(-), 8(+), and 10(+) alpha-cluster states occurring in the excitation-energy range 11-25 MeV and forming a rotational band without parity splitting. These results supplement the pattern of the alpha-cluster structure of excited states that is currently believed to exist in light even-even nuclei from O-16 to Ti-44.

..cap alpha..t angular correlation functions have been measured for the process /sup 12/C(/sup 7/Li,t)/sup 16/O(..cap alpha..)/sup 12/C corresponding to the levels 20.9 MeV (7/sup -/), 16.3 MeV (6/sup +/), and 14.6 MeV (5/sup -/) of the /sup 16/O nucleus. The measurements were made for a /sup 7/Li beam energy 45 MeV in the complete range of angles (0--180/sup 0/ ). The measured functions are well described by squares of Legendre polynomials of order 7, 6, and 5, respectively. The suppression of the intensity of the first maximum in the correlation function for the 20.9-MeV level which was observed in the reaction (/sup 6/ Li,d) in our previous study was not observed in the (/sup 7/ Li,t) reaction.

Angular /ital d/..cap alpha.. correlations are measured for the process/sup 12/C(/sup 14/N,/ital d/)/sup 24/Mg*(..cap alpha..)/sup 20/Ne at /sup 14/N ion energy of 32.4 MeVand at an angle of theta/sub /ital d//=0/degree/. The angular correlationcorresponding to populating of the 13.45 MeV level of /sup 24/Mg gives evidence ofa direct mechanism for the /sup 12/C(/sup 14/N,/ital d/)/sup 24/Mg reaction and confirmsthe results of our previous measurements.

The possibility of use of reactions induced by /sup 14/N such as /sup 14/N+/sup 12/C..-->..d+/sup 12/C+/sup 12/C for study of quasimolecular states is investigated. The results indicate that such investigations are promising.

We have measured d..cap alpha.. angular correlations in the reaction /sup 14/C(/sup 6/Li,d)/sup 18/O(..cap alpha..)/sup 14/C at a /sup 6/Li ion energy 32 MeV. Quantum numbers have been determined for the /sup 18/O states with excitation energies 12.6 MeV (5/sup -/), 17.05 MeV (7/sup -/), and 18.95 MeV (7/sup -/). The probabilities of population and the widths of the states found indicate an expressed ..cap alpha..-cluster structure. The energy locations of the ..cap alpha..-cluster levels 7/sup -/ found in various light nuclei are compared.

Spectra of d..cap alpha.. coincidences have been measured in the reactions /sup 12/C(/sup 6/Li,d)/sup 16/O(..cap alpha..)/sup 12/C and /sup 16/O(/sup 6/Li,d)/sup 20/Ne (..cap alpha..)/sup 16/O at lithium-ion energies 60, 75, and 90 MeV. In coincidence spectra corresponding to the interval 30--50 MeV of excitation energy of /sup 16/O and /sup 20/Ne nuclei, no manifestations were observed of the existence of ..cap alpha..-cluster levels built on the ground states of /sup 12/C and /sup 16/O. The results of the measurements may indicate existence in /sup 16/O of ..cap alpha..-cluster levels in the interval 32--36 MeV built on the first two excited states of /sup 12/C.