Photonuclear and atomic cross sections of /sup 27/Al between 3 and 38 MeV

Journal Article · Tue Sep 01 04:00:00 EDT 1987 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.36.911· OSTI ID:6286038

Sherman, N K; Davidson, W F; Ahrens, J

The total cross section for photon absorption of Al was measured for energies between 3 and 38 MeV with a el-ray spectrometer consisting of a liquid deuterium target viewed by a photoneutron time-of-flight detector. Corrections to the observed total cross section for background electromagnetic processes in the absorber were computed by a Monte Carlo method. Between 5 and 8 MeV where the photonuclear cross section sigma/sub N/ is negligible and the uncertainty in the measurements is small, values of the atomic cross section sigma/sub Z/ calculated by others systematically exceed the measured values by 0.7%. In this energy interval sigma/sub Z/ is mainly due to incoherent photon scattering by atomic electrons. Nonrelativistic atomic form factors and estimated radiative corrections used in calculating the tabulated incoherent scattering cross sections introduced enough uncertainty to justify decreasing sigma/sub incoh/ by 0.87% to bring sigma/sub Z/ into agreement with experiment. Correcting this discrepancy causes the integral between 10 and 38 MeV of sigma/sub N/, which has a maximum value of about 5% of sigma/sub Z/, to increase by 18% to 500 MeV mb. We conclude that the giant dipole resonance of /sup 27/Al has a strength of 1.24 classical sum rule units.

• Research Organization: Division of Physics, National Research Council of Canada, Ottawa, Ontario, Canada K1A0R6
• OSTI ID: 6286038
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Journal Issue: 3 Vol. 36:3; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651420* -- Nuclear Properties & Reactions
A=20-38
Experimental
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALUMINIUM 27 TARGET
ATOMS
BARYONS
CAPTURE
CORRECTIONS
CROSS SECTIONS
DATA
DIPOLE MOMENTS
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
EXPERIMENTAL DATA
FERMIONS
FORM FACTORS
GAMMA SPECTROMETERS
GIANT RESONANCE
HADRONS
INCOHERENT SCATTERING
INFORMATION
MEASURING INSTRUMENTS
MEV RANGE
MEV RANGE 01-10
MEV RANGE 10-100
MONTE CARLO METHOD
NEUTRONS
NUCLEAR REACTIONS
NUCLEONS
NUMERICAL DATA
PARTICLE PROPERTIES
PHOTONEUTRONS
PHOTONUCLEAR REACTIONS
PHOTONUCLEONS
RADIATIVE CORRECTIONS
RESONANCE
SCATTERING
SPECTROMETERS
SUM RULES
TARGETS
TIME-OF-FLIGHT METHOD
TOTAL CROSS SECTIONS