Photoneutron cross sections for /sup 15/N

Journal Article · Wed Sep 01 00:00:00 EDT 1982 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.26.777· OSTI ID:6701344

Jury, J W; Berman, B L; Woodworth, J G; Thompson, M N; Pywell, R E; McNeill, K G

Photoneutron cross sections involving the emission of one and two neutrons from /sup 15/N have been measured over the excitation energy interval from threshold (10.8 MeV) to 38 MeV using monoenergetic photons from the annihilation in flight of fast positrons. A very broad giant dipole resonance extending from about 16 to 30 MeV was observed, with a maximum (..gamma..,n/sub tot/) cross section of about 11 mb at 23.5 MeV. The magnitude of the measured average photoneutron energies shows that most of the strength below 15 MeV decays to the ground state of /sup 14/N, whereas most of the strength in the giant resonance decays to excited states. Comparison with particle-capture cross-section data indicates that multiparticle-multihole interference effects probably account for some of the pronounced intermediate structure observed above 16 MeV in the (..gamma..,n) cross section. Comparison with a recent shell-model calculation favors the use of a Tabakin potential over a delta-function force with a Soper exchange mixture, in marked contrast with recent corresponding results for /sup 13/C and /sup 17/O. Features of recently measured photoreaction cross sections for the /sup 12/C, /sup 13/C, /sup 14/N, /sup 15/N, /sup 16/O, /sup 17/O, and /sup 18/O nuclei are compared as well.

• Research Organization: Lawrence Livermore National Laboratory, University of California, Livermore, California 94550
• OSTI ID: 6701344
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 26:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651325* -- Nuclear Properties & Reactions
A=6-19
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
BARYONS
CROSS SECTIONS
DIPOLE MOMENTS
ELEMENTARY PARTICLES
EMISSION
ENERGY RANGE
FERMIONS
GIANT RESONANCE
HADRONS
ISOTOPES
LIGHT NUCLEI
MEV RANGE
MEV RANGE 10-100
NEUTRON EMISSION
NEUTRONS
NITROGEN 14
NITROGEN 15 TARGET
NITROGEN ISOTOPES
NUCLEAR REACTIONS
NUCLEI
NUCLEONS
ODD-ODD NUCLEI
PHOTONEUTRONS
PHOTONUCLEAR REACTIONS
PHOTONUCLEONS
RESONANCE
STABLE ISOTOPES
TARGETS