Neutron emission from products of strongly damped reactions sup 58 Ni+ sup 165 Ho at 930 MeV

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · Physical Review (Section) C: Nuclear Physics; (USA)

DOI:https://doi.org/10.1103/PhysRevC.40.692· OSTI ID:5539548

Petitt, G A; Butler, C; Penumetcha, V ^[1]; Awes, T C ^[1]; Beene, J R ^[1]; Ferguson, R L ^[1]; Obenshain, F E ^[1]; Plasil, F ^[1]; Young, G R ^[2]; Sorensen, S P ^[3]; others, and

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1. Georgia State University, Atlanta, Georgia 30303 (US)
2. Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
3. University of Tennessee, Knoxville, Tennessee 37996 Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831

Neutron time-of-flight spectra have been measured for emission from products of reactions between {sup 58}Ni and {sup 165}Ho at a bombarding energy of 930 MeV. Neutrons were detected in coincidence with projectilelike fragments from strongly damped reactions using a heavy ion {Delta}{ital E}-{ital E} telescope which permitted the total kinetic energy loss to be extracted for each event. The neutron spectra were separated into 25-MeV-wide total kinetic energy loss bins over the total kinetic energy loss range from 0 to 450 MeV. Moving source fits were made to the neutron spectra to determine emission temperatures, multiplicities, velocities, and angles for the projectilelike fragment, targetlike fragment, and nonequilibrium emission sources as a function of the total kinetic energy loss. The extracted temperature of the projectlike fragment is found to be larger than that of the targetlike fragment source at all total kinetic energy losses, approaching that of the targetlike fragment only at the largest total kinetic energy losses. The results suggest an equal division of the available excitation energy at small total kinetic energy loss with a thermal energy division occurring only at the largest total kinetic energy losses. The velocity of the nonequilibrium source is found to remain constant at approximately one-half of the beam velocity independent of the final projectlike fragment velocity. This result supports models of nonequilibrium emission in which nucleon emission is isotropic in the nucleon-nucleon center-of-mass system as opposed to models in which the nonequilibrium emission occurs isotropically from the heavy fragments along their reaction trajectories.

• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5539548
• Journal Information: Physical Review (Section) C: Nuclear Physics; (USA), Vol. 40:2; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
HOLMIUM 165 TARGET
NICKEL 58 REACTIONS
FRAGMENTATION
ANGULAR DISTRIBUTION
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
MEV RANGE 100-1000
MULTIPLICITY
NEUTRON EMISSION
NEUTRON SPECTRA
NUCLEON-NUCLEON INTERACTIONS
TIME-OF-FLIGHT METHOD
BARYON-BARYON INTERACTIONS
CHARGED-PARTICLE REACTIONS
DISTRIBUTION
EMISSION
ENERGY RANGE
HADRON-HADRON INTERACTIONS
HEAVY ION REACTIONS
INTERACTIONS
MEV RANGE
NUCLEAR REACTIONS
PARTICLE INTERACTIONS
SPECTRA
TARGETS
651820* - Nuclear Properties & Reactions
A=150-189
Experimental