({sup 16}O + {sup 232}Th) incomplete fusion followed by fission at 140 MeV

Thesis/Dissertation · Fri Dec 31 04:00:00 EST 1993

OSTI ID:111245

Gavathas, E P

Cross sections for incomplete fusion followed by fission have been measured for the reaction ({sup 16}O + {sup 232}Th) at 140 MeV. In plane and out of plane measurements were made of cross sections for beamlike fragments in coincidence with fission fragments. The beamlike fragments were detected with the Florida State large acceptance Bragg curve spectrometer. The detector was position sensitive in the polar direction. The beamlike particles observed in coincidence with fission fragments were He, Li, Be, B, C, N and O. Fission fragments were detected by three surface barrier detectors using time of flight for particle identification. The reaction cross section due to incomplete fusion is 747 {+-} 112 mB, or 42% of the total fission cross section. The strongest incomplete fusion channels were the helium and carbon channels. The average transferred angular momentum for each incomplete fusion channel was calculated using the Q{sub opt} model of Wilczynski, and the angular correlation was calculated using the saddle point transition state model. The K distribution was determined from the Rotating Liquid Drop model. The theoretic angular distributions were fitted to the experimental angular distributions with the angular momentum J and the dealignment factor {alpha}{sub 0} as free parameters. The fitted parameter J was in excellent agreement with the Q{sub opt} model predictions. The conclusions of this study are that the incomplete fusion cross section is a large part of the total cross section, and that the saddle point transition state model adequately describes the observed angular correlations for fission following incomplete fusion.

• Research Organization: Florida State Univ., Tallahassee, FL (United States)
• OSTI ID: 111245
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CROSS SECTIONS
FISSION
FISSION FRAGMENTS
INCOMPLETE FUSION REACTIONS
LIQUID DROP MODEL
OXYGEN 16 REACTIONS
THALLIUM