Neutron hole states in /sup 207,206,205/Pb isotopes via the (/sup 3/He,. cap alpha. ) reaction at 100 MeV

Journal Article · Fri Feb 29 23:00:00 EST 1980 · Phys. Rev., C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.21.879· OSTI ID:5482742

Guillot, J; Van de Wiele, J; Langevin-Joliot, H; Gerlic, E; Didelez, J P; Duhamel, G; Perrin, G; Buenerd, M; Chauvin, J

Neutron hole states were investigated in the /sup 207,206,205/Pb isotopes up to 25 MeV excitation energy using the (/sup 3/He,..cap alpha..) reaction at 100 MeV incident energy with 100 keV energy resolution. Above the well-matched low-lying levels corresponding to high angular momentum transfers, new peaks are identified. In addition, three gross structures, riding on a continuous background, are observed in each of the three isotopes, with some fine structures showing up to 10 MeV excitation energy. For /sup 207/Pb, angular distributions have been obtained for the low-lying levels as well as for the deeply bound hole states. The data have been analyzed with distorted-wave Born-approximation calculations and spectroscopic factors extracted. It has been found that the low-lying levels do not exhaust the 1i13/2 and 1h9/2 neutron hole strengths. Corrections for exact finite-range effects, form factor shapes, and indirect pickup contributions have been calculated, and modify significantly the 2f 7/2 spectroscopic measured strength but not the 1i13/2 and the 1h9/2 ones. Most of the 1i13/2 and 1h9/2 missing strengths are found in the ''bump'' located at about 5 MeV excitation energy. The highly fragmented bump observed at about 8 MeV excitation energy is shown to arise from 1h11/2 neutron pickup exhausting 45% of the sum-rule limit. Finally, the very smooth structure extending to 21 MeV excitation energy is tentatively attributed to 1g7/2+1g9/2 neutron holes with 80% of the total strength. In /sup 207/Pb, the four first isobaric analog states are observed as narrow structures around 20 MeV excitation energy.

• Research Organization: Institut de Physique Nucleaire, BP n/sup o/ 1, 91406 Orsay, France
• OSTI ID: 5482742
• Journal Information: Phys. Rev., C; (United States), Journal Name: Phys. Rev., C; (United States) Vol. 21:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

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73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA SPECTRA
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BETA DECAY RADIOISOTOPES
CHARGED-PARTICLE REACTIONS
DIRECT REACTIONS
DISTRIBUTION
ELECTRON CAPTURE RADIOISOTOPES
ENERGY LEVELS
ENERGY RANGE
EQUATIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
HEAVY NUCLEI
HELIUM 3 REACTIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LEAD 205
LEAD 206
LEAD 206 TARGET
LEAD 207
LEAD 207 TARGET
LEAD 208 TARGET
LEAD ISOTOPES
MAGNETIC SPECTROMETERS
MATHEMATICAL MODELS
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 100-1000
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
ONE-NUCLEON TRANSFER REACTIONS
PARITY
PARTICLE PROPERTIES
PARTICLE-HOLE MODEL
PICKUP REACTIONS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
SPECTRA
SPECTROMETERS
SPECTROSCOPIC FACTORS
SPIN
STABLE ISOTOPES
SUM RULES
TARGETS
TRANSFER REACTIONS
YEARS LIVING RADIOISOTOPES