NEUTRON SPECTRA FROM MONOENERGETIC PHOTONS OF BISMUTH.

Abstract

The technique for obtaining monochromatic photons from the 25 MeV betatron of the University of Illinois was extended to permit the measurement of neutron spectra from (gamma, n) reactions over the giant resonance region. Previous experiments with the bremsstrahlung monochromator involved the study of elastic and quasielastic scattering of gamma-rays. Neutron detection entailed new techniques, such as the discrimination against the high gamma-ray background, the development of a time-of-flight measuring apparatus, and a method for data analysis. The new technique used in this experiment presents the advantage that both the photon and neutron energies are known, and furthermore that the photon energy can be varied continuously. The experimental results were found to be in agreement with available theoretical calculations based on the particlehole model. Schematically this model was proposed to show how the residual particle-hole interaction could combine single particle excitations, arising in the absorption of a dipole gamma-ray, so as to produce a coherent giant dipole state.

Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1965
Accession Number
AD0625463

Entities

People

  • Franca Tagliabue Kuchnir

Organizations

  • University of Illinois Urbana–Champaign

Tags

DTIC Thesaurus Topics

  • Data Analysis
  • Detection
  • Diffraction
  • Gamma Rays
  • Measurement
  • Neutron Spectrum
  • Particles
  • Scattering
  • Spectra

Fields of Study

  • Physics

Readers

  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Solar Physics
  • Theoretical Analysis.