Determination of Nuclidic Ratios in Geological Samples with Neutron Capture Gamma Rays

Abstract

<p> This thesis is divided into two parts, the first part being devoted to the application of Neutron Capture Gamma Ray Analysis in determining S/Si and Fe/Si ratios in Allende meteorite and lunar samples and the second part, to evidence for a possible iron isotopic anomaly in the Allende meteorite obtained by the same method. The samples were irradiated in an in-core irradiation system in the McMaster swimming-pool nuclear reactor and the collimated beam of gamma rays was detected by a pair-spectrometer consisting of a Ge(Li) detector and NaI annulus. In the first part, besides the mainstream of the work, the basic principles of Neutron Capture Gamma Ray Analysis and Neutron Activation Analysis and the supremacy of the former over the latter for this particular problem has been discussed. In the second part, along with the implications and evidence of isotopic variations of other elements in the Allende meteorite, a brief description of the classification, structure and mineralogy of the Allende meteorite is given. The success and advantage of the method along with its limitations and further directions along these lines are also discussed.</p>