Experimental studies of the resonance at E/sub c.m./ = 19.7 MeV in the $sup 12$C + $sup 16$O system

Journal Article · Mon Dec 01 00:00:00 EST 1975 · Phys. Rev., C, v. 12, no. 6, pp. 1907-1917

OSTI ID:4102797

Shapira, D; Stokstad, R G; Sachs, M W; Gobbi, A; Bromley, D A

A resonance appearing in the $sup 12$C + $sup 16$O system at a center-of- mass incident energy of 19.7 MeV has been studied experimentally. Excitation functions for the $sup 12$C + $sup 16$O inelastic scattering and the $sup 12$C($sup 16$O, $alpha$$)$$sup 24$Mg* and $sup 12$C($sup 16$O, p)$sup 27$Al* reaction channels were measured. The width of the resonance was shown to be more than double the average level width in $sup 28$Si at excitation energies around 36.5 MeV where this resonance appears. The resonance is enhanced at large angles in the elastic and inelastic channels and it is found to be equally strong at theta/sub c.m./ = 3degree and 177degree for the $sup 12$C($sup 16$O, p)$sup 27$Al reaction. The yield of 6.13 MeV $gamma$ radiation has been measured and is observed to resonate at E/sub c.m./ = 19.7 MeV. High resolution measurements of the particle yield at E/sub c.m./ = 19.7 MeV, theta/sub lab/ = 7.5degree for the reaction $sup 12$C($sup 16$O, $sup 12$C)$sup 16$O* (6.05, 6.13 MeV) show that the 3$sup -$ (6.13 MeV) state is populated much more strongly than the 0$sup +$ (6.05 MeV) state. These results do not support the suggestion that the resonance has a $sup 12$C-$alpha$$-$$sup 12$C molecular structure. Measurements of inelastic scattering at higher energies suggest the existence of additional correlated structures. A statistical analysis of the $alpha$-particle lds indicates that both compound and direct mechanisms contribute to the reaction. A discussion of the properties of the resonance in terms of intermediate structure and the statistical theory of Moldauer is given. (AIP)

• Research Organization: Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut
• NSA Number: NSA-33-018889
• OSTI ID: 4102797
• Journal Information: Phys. Rev., C, v. 12, no. 6, pp. 1907-1917, Other Information: Orig. Receipt Date: 30-JUN-76
• Country of Publication: United States
• Language: English

Related Subjects

N68351* -Physics (Nuclear
Experimental)-Nuclear Properties & Reactions
6 <= A <= 19-Nuclear Reactions & Scattering
642005*
*CARBON 12 TARGET- OXYGEN 16 REACTIONS
*CARBON 12- OXYGEN 16 REACTIONS
ALPHA-TRANSFER REACTIONS- OXYGEN 16
ALUMINIUM 27- COMPOUND- NUCLEUS REACTIONS- PROTONS
CORRECTIONS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION FUNCTIONS
INTERMEDIATE RESONANCE
INTERMEDIATE STRUCTURE
MEV RANGE 10-100
STATISTICAL MODELS ALPHA PARTICLES- COMPOUND-NUCLEUS REACTIONS- MAGNESIUM 24