Accession Number:

AD0405434

Title:

INTERPRETATION OF QUASI-ELASTIC SCATTERING OF 11-19 MeV MONOCHROMATIC PHOTONS BY HOLMIUM USING ZERO-POINT VIBRATIONS IN THE HYDRODYNAMIC MODEL,

Descriptive Note:

Corporate Author:

ILLINOIS UNIV URBANA

Personal Author(s):

Report Date:

1962-08-22

Pagination or Media Count:

17.0

Abstract:

A bremsstrahlung monochromator was used to measure asi-elastic scattering of photons by Holmium-165 at 48 energies between 10.92 and 19.06 MeV. No very fine structure was observed but the gross splitting of the giant dipole resonance of this deformed nucleus into two peaks was clearly resolved. The 135 degree differential scattering cross section has maxima of 12.49 MeV 0.35 mbsr and 16.50 MeV 0.45 mbsr a minimum occurs at 13.50 MeV 0.28 mbsr. The observed energy dependence confirms the existence of tensor polarizability i.e., the absorption cross section depends on the relative orientation of the nuclear spin and the photon polarization. The combination of the observed scattering and photoabsorption results can be used to test photo nuclear models the existing data suggest that it may be necessary to refine the hydrodynamic model by including zero-point vibrations. The absolute magnitude of the scattering implies that the previously reported energy-integrated absorption cross section should be reduced by 21 this reduces the integrated sum in the giant resonance to 1.07 0.16 times the sum rule prediction with out exchange forces. Author

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Distribution Statement:

APPROVED FOR PUBLIC RELEASE