Isomeric yield ratios in proton-, sup 3 He-, and. alpha. -particle-induced reactions on sup 197 Au
- Department of Radioisotopes, Japan Atomic Energy Research Institute, Tokai-mura, Ibaraki 319-11 (JP) Japan Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, Setagaya-ku, Tokyo 158, Japan (JP)
Excitation functions and mean projected recoil-ion ranges of the isomeric nuclei produced in proton-, {sup 3}He-, and {alpha}-particle-induced reactions on {sup 197}Au were measured by an activation technique for bombarding energies {ital E}{sub {ital p}}{approx lt}50 MeV, and {ital E} {sub {sup 3}He,{alpha}}{approx lt}40 MeV. Isomeric yield ratios ({sigma}{sub {ital m}}/{sigma}{sub {ital g}}) were determined as a function of the incident particle energy. The experimental excitation functions and isomeric yield ratios were compared with those from statistical model calculations based on the Hauser-Feshbach formalism. From the analysis of excitation functions, recoil-ion ranges, and isomeric yield ratios, the observed reactions were able to be grouped into three distinctly different ones in the energy region studied: (i) compoundlike reaction for ({ital p},3{ital n}), ({sup 3}He,4{ital n}), ({alpha},3{ital n}), and ({ital p},{ital pn}){sup 196}Au{sup {ital m}}, (ii) one-neutron stripping reaction for ({sup 3}He,2{ital p}), and (iii) nonequilibrium one-neutron knockout or pickup reactions with transfer of a small amount of angular momentum for the ({sup 3}He,{alpha}), ({alpha},{alpha}{ital n}), and ({ital p},{ital pn}){sup 196}Au{sup {ital g}} that are intermediate between (i) and (ii). We propose a semiempirical method which predicts isomeric yield ratios in the compoundlike reactions, within a factor of 0.7 to 1.4, from the spin distribution of the compound nucleus.
- OSTI ID:
- 6915430
- Journal Information:
- Physical Review, C (Nuclear Physics); (USA), Vol. 41:3; ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
Similar Records
ISOMERIC CROSS-SECTION RATIOS FOR REACTIONS PRODUCING THE ISOMERIC PAIR Hg$sup 197$,$sup 197$m
Entrance and exit channel phenomena in d- and /sup 3/He-induced preequilibrium decay
Related Subjects
ALPHA REACTIONS
COMPOUND-NUCLEUS REACTIONS
GOLD 197 TARGET
HELIUM 3 REACTIONS
PROTON REACTIONS
ISOMERIC NUCLEI
NUCLEAR REACTION YIELD
ENERGY DEPENDENCE
EXCITATION FUNCTIONS
HAUSER-FESHBACH THEORY
MEV RANGE 10-100
PICKUP REACTIONS
RECOILS
STATISTICAL MODELS
STRIPPING
BARYON REACTIONS
CHARGED-PARTICLE REACTIONS
CROSS SECTIONS
DIRECT REACTIONS
ENERGY RANGE
FUNCTIONS
HADRON REACTIONS
MATHEMATICAL MODELS
MEV RANGE
NUCLEAR REACTIONS
NUCLEAR THEORY
NUCLEI
NUCLEON REACTIONS
TARGETS
TRANSFER REACTIONS
YIELDS
651920* - Nuclear Properties & Reactions
A=190-219
Experimental