Accurate Determination of High Energy Gamma-Ray Standards

Published

October 16, 2008

Author(s)

Ernest G. Kessler Jr., Maynard S. Dewey, R Deslattes, Albert Henins, H G. Borner, M Jentschel, H Lehmann

Abstract

The extension of accurate crystal diffraction spectroscopy to the 2 to 6 MeV region is described. Gamma-ray standards with a relative uncertainty of (2 to 5)x10^-7 are obtained by measuring the small diffraction angles (a few tenths of a degree) through which the gamma rays are diffracted. Accurate knowledge of the crystal lattice spacing provides a wavelength scale that is consistent with the definition of the meter. The procedures and the facilities for measuring the small diffraction angles are briefly described. Measurements on gamma rays produced in neutron capture reactions involving H, ³²S, and ³⁵Cl are used to demonstrate the measurement capability that has been achieved. The relationship between accurate gamma ray and atomic mass measurements is described along with contributions to the fundamental constants such as the neutron mass.

Citation

International Symposium on Capture Gamma-Ray Spectroscopy

Pub Type

Journals

Keywords

atomic masses, crystal diffraction, gamma-ray standards

Citation

Kessler Jr., E. , Dewey, M. , Deslattes, R. , Henins, A. , Borner, H. , Jentschel, M. and Lehmann, H. (2008), Accurate Determination of High Energy Gamma-Ray Standards, International Symposium on Capture Gamma-Ray Spectroscopy (Accessed October 21, 2025)