Neutron-interferometric measurements of the coherent scattering length of the isotopes of silver

Employing a new measuring scheme with the D18 neutron interferometer at the ILL, Grenoble, the thermal neutron coherent scattering length bsub(c) for bound atoms of natural Ag, 107Ag and 109Ag have been measured at the wavelength lambda = 1.8742 A. The results, corrected for composition and density of the actual samples, are nat Ag: bsub(c) = 5.922(7) fm 107Ag: 107bsub(c) = 7.555(11) fm 109Ag: 109bsub(c) = 4.165(11) fm. The result is in agreement with an earlier value obtained with the interferometer for nat Ag(5.932(6)) using a different measuring scheme and a totally different sample. For nat Ag and 107Ag the values determined interferometrically are approx. equal to0.05 and approx. equal to0.08 fm smaller, respectively, than those measured with the Christiansen filter method. (orig.)