A study of the higher excitation levels of /sup 11/B via the /sup 10/B(n,n)/sup 10/B and /sup 10/B(n,n')/sup 10/B*(0. 72, 1. 74, 2. 15, 3. 59, 4. 77 MeV) reactions

Technical Report · Tue Nov 01 04:00:00 EST 1988

OSTI ID:6645320

Sadowski, E T

As part of the study of the higher energy-level structure of /sup 11/B, cross sections for elastic and inelastic scattering of neutrons from isotopically enriched /sup 10/B samples have been measured for incident neutron energies from 3.03 MeV to 6.45 MeV in 250 keV increments and from 7.02 MeV to 12.01 MeV in 500 keV increments. Inelastic angular distributions for scattering to the states in parentheses in /sup 10/B have been measured from the indicated energy up to 12.01 MeV; (0.718) from 3.02 MeV; (1.74) from 3.27 MeV; (2.15) from 3.77 MeV; (3.59) from 5.52 MeV; (4.77) from 7.02 MeV. The measurements at 3.02, 3.51, 4.02, and 4.51 MeV were done at nine laboratory angles from 20/degree/ to 158/degree/ in 17.5/degree/ increments with a sample that is isotopically 95.86% /sup 10/B. All other distributions measured scattering at 11 laboratory angles from 18/degree/ to 158/degree/ in 15/degree/ increments from a sample that is isotopically 99.49% /sup 10/B. The data are corrected for air scattering, sample attenuation, minor isotope impurity, multiple scattering, and elastic and inelastic scattering from the sample of the neutron source continuum and contaminants. An eight-channel, multilevel R-matrix analysis was performed on the data. Level energies, spins, and parities were deduced for twelve levels above 13 MeV excitation in /sup 11/B. Only two definite and three tentative assignments for T = /1/2/ levels had been made previously above 13 MeV. The two definite levels were confirmed. Good agreement between the data and the R-matrix calculation in all analyzed channels was obtained for the proposed structure. 122 refs., 40 figs., 7 tabs.

• Research Organization: Ohio Univ., Athens (USA). Dept. of Physics
• DOE Contract Number: FG02-88ER40387
• OSTI ID: 6645320
• Report Number(s): DOE/ER/40387-2; ON: DE89003254
• Country of Publication: United States
• Language: English

Related Subjects

651320* -- Nuclear Properties & Reactions
A=6-19
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
BARYON REACTIONS
BORON 10 TARGET
CROSS SECTIONS
DATA ANALYSIS
DISTRIBUTION
ELASTIC SCATTERING
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
HADRON REACTIONS
INELASTIC SCATTERING
MATHEMATICAL MODELS
MATRICES
NEUTRON REACTIONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEON REACTIONS
R MATRIX
SCATTERING
SHELL MODELS
TARGETS