PHOTONEUTRON CROSS SECTIONS OF Tb$sup 159$ AND O$sup 1$$sup 6$

Journal Article · Mon Feb 24 04:00:00 EST 1964 · Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D

DOI:https://doi.org/10.1103/PhysRev.133.B869· OSTI ID:4074520

Bramblett, R L; Caldwell, J T; Harvey, R R; Fultz, S C

The photoneutron cross sections of O/sup 16/ and Tb/sup 159/ were measured up to 30 Mlev using photons of 3% resolution resulting from positron annihilation-in-flight. Thirteen resonances corresponding to levels in O/sup 16/ were observed in the O/sup 16/ ( gamma ,n) reaction. One, at 29 plus or minus 1 Mev, is previously unreported. The O/sup 16/( gamma ,n) cross section integrated to 30 Mev is 46 plus or minus 5 Mev-mb. Both the ( gamma ,n) and ( gamma ,2n) cross sections of Tb were measured using a statistical counting technique. The ratio of the two cross sections determines that the level density parameter, a = 17 plus or minus 5 (Mev)/sup -1/. The sum of the ( gamma ,n) and ( gamma ,2n) cross sections is a double peaked giant E1 resonance, from which the intrinsic quadrupole moment was determined to be 7.0 plus or minus 1.1 b. Additional structure in the Tb/sup 159/( gamma ,n) cross section was observed at 10.1 Mev. The sum of the ( gamma ,n) and ( gamma ,2n) cross sections of Tb/sup 159/, integrated to 28 Mev, is 2.3 plus or minus 0.2 Mev-b. (auth)

• Research Organization: Univ. of California, Livermore
• NSA Number: NSA-18-009408
• OSTI ID: 4074520
• Report Number(s): UCRL-7156; 0031-899X
• Journal Information: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D, Journal Name: Physical Review (U.S.) Superseded in part by Phys. Rev. A, Phys. Rev. B: Solid State, Phys. Rev. C, and Phys. Rev. D Vol. Vol: 133; ISSN PHRVA
• Country of Publication: United States
• Language: English

Related Subjects

ANNIHILATION
COUNTERS
CROSS SECTIONS
ELECTRIC MOMENTS
ENERGY LEVELS
GAMMA RADIATION
MEASURED VALUES
NEUTRON DETECTION
NUCLEAR MODELS
OXYGEN 16
PHOTONEUTRONS
PHYSICS
POSITRONS
RESOLUTION
RESONANCE
STATISTICS
TERBIUM 159