Pre-equilibrium emission effects in the measured isomeric yield ratios in alpha-induced reactions on sup 197 Au

Journal Article · Sun Mar 01 04:00:00 EST 1992 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.45.1171· OSTI ID:7205935

Chakravarty, N ^[1]; Sarkar, P K ^[2]; Ghosh, S ^[3]

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1. Radiochemistry Division, Bhabha Atomic Research Centre, Bombay 400085 (India)
2. Health Physics Unit, Variable Energy Cyclotron Centre, I/AF Bidhan Nagar, Calcutta 700064 (India)
3. Saha Institute of Nuclear Physics, I/AF Bidhan Nagar, Calcutta 700064 (India)

Excitation functions of isomeric yields have been measured for {sup 198}Tl, {sup 197}Hg, {sup 198}Au, and {sup 196}Au produced by {alpha}+{sup 197}Au reactions in the 35--50 MeV energy range. The isomeric yield ratios are analyzed in terms of pre-equilibrium and evaporation emissions. Single as well as two-nucleon pre-equilibrium emissions are taken into account. Various combinations of pre-equilibrium and equilibrium emissions together with different sequences in which the ejectiles may be emitted are explicitly considered to evaluate the average spin distribution of the final nucleus. The choice of the spin cutoff parameter and the effect of forward-angle emissions of pre-equilibrium particles have been investigated. The isomeric yield ratios are found to depend sensitively on the pre-equilibrium angular distribution and on the spin cutoff parameter for equilibrium emissions. Inadequate description of the reaction mechanism leads to incorrect predictions of excitation functions as well as isomeric yield ratios.

• OSTI ID: 7205935
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 45:3; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR MOMENTUM
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
CROSS SECTIONS
DAYS LIVING RADIOISOTOPES
DIRECT REACTIONS
ELECTRON CAPTURE RADIOISOTOPES
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EXCITATION FUNCTIONS
FUNCTIONS
GOLD 196
GOLD 197 TARGET
GOLD 198
GOLD ISOTOPES
HEAVY NUCLEI
HELIUM 4
HELIUM ISOTOPES
HOURS LIVING RADIOISOTOPES
INTERNAL CONVERSION RADIOISOT
INTERNAL CONVERSION RADIOISOTOPES
ISOMER RATIO
ISOMERIC NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LIGHT NUCLEI
MERCURY 197
MERCURY ISOTOPES
NUCLEAR REACTIONS
NUCLEI
ODD-ODD NUCLEI
PARTICLE PROPERTIES
PROTON SPECTRA
RADIOISOTOPES
SPECTRA
SPIN
STABLE ISOTOPES
TARGETS
THALLIUM 198
THALLIUM ISOTOPES
TRANSFER REACTIONS