While INAA is becoming a less popular analytical technique and it is a mature tool, there are still many improvement happening in the field. The effect of the new semi-planar detector is evaluated as compared to geological reference material and as its performance to the classical coaxial detector. The semi-planar detector offers improved accuracy (about 5%) for many analytes (As, Ba, Ce, Co, Cr, Eu, Hf, Lu, Nd, Rb, Sm, Th, U, Yb and Zn) while the coaxial gives an accuracy in the range of 10-15%.
The platinum-group elements (PGEs) are commonly determined by INAA and ICP-MS after a NiS fire assay preconcentration. The results of the initial round robin for the PGEs and gold were examined for geological Canadian reference materials (WGB-1, TDB-1, UMT-1, WPR-1, WMG-1, and WMS-1). The Au accuracy is generally within 15% for both methods. For Ir, Os, Pd, Pt and Rh the accuracy for most samples is better than 10% for FA-ICP-MS and FA-INAA (true only for sulfide-bearing samples in the case of FA-INAA). Ru is not very accurate by either methods. Ru and Au have problems with precision which is interpreted to be related to the loss of gold in the dissolution step and for Ru, the source of the problem is not yet understood. Kurtosis show that FA-INAA has higher clustering than FA-ICP-MS for most analytes. It suggests a slightly better precision for FA-INAA. This is explained by the robustness of INAA after the NiS preconcentration despite its lower instrumental precision versus the complex dissolution steps involved in ICP-MS. For samples richer in PGEs (sulfide- and/or oxide-bearing rocks) both methods perform adequately but for low PGEs concentration samples (crustal rocks) ICP-MS shows an advantage.
Authors:J. Calvert, D. Lees, D. Derry, and D. Barnes
The various nuclear techniques which have been used to study oxygen self-diffusion in oxides are discussed. Results are given
for measurements using resonance capture in the18O(p, α)15N and18O(p, γ)19F reactions and the different techniques are compared.
Authors:P. Horlock, J. Clark, I. Goodier, J. Barnes, G. Bentley, P. Grant, and H. O’Brien
82Sr has now been produced by the spallation of Molybdenum by protons of up to 800 MeV. The radiochemical recovery of strontium
is described together with a description of the analytical techniques used to estimate recovered yields of the various radionuclides
generated. A radionuclide generator is described for the rapid recovery of82Rb, the 1.25 min half-life decay product of82Sr. An outline is given of the quality control procedure adopted to ensure that the82Rb is suitable for clinical use.
Authors:L. Tandon, E. Hastings, J. Banar, J. Barnes, D. Beddingfield, D. Decker, J. Dyke, D. Farr, J. FitzPatrick, D. Gallimore, S. Garner, R. Gritzo, T. Hahn, G. Havrilla, B. Johnson, K. Kuhn, S. LaMont, D. Langner, C. Lewis, V. Majidi, P. Martinez, R. McCabe, S. Mecklenburg, D. Mercer, S. Meyers, V. Montoya, B. Patterson, R. Pereyra, D. Porterfield, J. Poths, D. Rademacher, C. Ruggiero, D. Schwartz, M. Scott, K. Spencer, R. Steiner, R. Villarreal, H. Volz, L. Walker, A. Wong, and C. Worley
The goal of nuclear forensics is to establish an unambiguous link between illicitly trafficked nuclear material and its origin.
The Los Alamos National Laboratory (LANL) Nuclear Materials Signatures Program has implemented a graded “conduct of operations”
type analysis flow path approach for determining the key nuclear, chemical, and physical signatures needed to identify the
manufacturing process, intended use, and origin of interdicted nuclear material. This analysis flow path includes both destructive
and non-destructive characterization techniques and has been exercized against different nuclear materials from LANL’s special
nuclear materials archive. Results obtained from the case study will be presented to highlight analytical techniques that
offer the critical attribution information.