Coincidence study of alpha particle fragmentation at E/sub alpha/ = 140 MeV

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1980

OSTI ID:6291227

Koontz, R W

Results of an experimental study of the interaction of 140 MeV alpha particles with /sup 90/Zr nuclei resulting in fragmentation of the alpha particle are reported. The experimental observations of the study are analyzed and are found to show that alpha particle breakup reactions leading to at least 4-body final states, composed of two charged alpha particle fragments, contribute significantly to the singles yield of charged fragments observed at a fixed forward angle. The conclusions are based on coincidence measurements where one charged fragment is detected at a small forward angle which remains fixed, while the second charged fragment is detected at a series of coplanar secondary angles. The largest coincidence charged particle yield for the multiparticle final state events results from /sup 90/Zr(..cap alpha..,pp)X reactions, where both of the measured protons have energy distributions similar to the proton singles energy distributions. The second largest observed coincidence yield involving two charged fragments arises from /sup 90/Zr(..cap alpha..,pd)X reactions, where the p and d fragments, as in the /sup 90/Zr(..cap alpha..,pp)X reactions also have energy distribution similar to the singles energy distributions. Analysis of additional measurements, where alpha particle fragments at the fixed angle are detected in coincidence with evaporation and nonequilibrium particles at many coplanar angles, show that the alpha particle fragmentation reactions are also generally associated with large energy transfer to the target nucleus. A multiple scattering model of the fragmentation reaction is employed, in conjunction with the experimental observations, to estimate the cross sections for alpha particle fragmentation into multi-particle final states resulting in n, 2n, p, pp, d, dn, dp, t and /sup 3/He fragments. The estimated total cross section for all fragmentation reactions is 755 mb or approximately 38% of the total reaction cross section for 140 MeV alpha particle interactions with /sup 90/Zr.

• Research Organization: Maryland Univ., Baltimore (USA)
• OSTI ID: 6291227
• Country of Publication: United States
• Language: English

Related Subjects

651725* -- Nuclear Properties & Reactions
A=90-149
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA REACTIONS
BARYONS
BREAKUP REACTIONS
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DATA
DEUTERONS
ELEMENTARY PARTICLES
EXPERIMENTAL DATA
FERMIONS
HADRONS
INFORMATION
MATHEMATICAL MODELS
NUCLEAR FRAGMENTS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEONS
NUMERICAL DATA
PROTONS
TARGETS
TOTAL CROSS SECTIONS
ZIRCONIUM 90 TARGET