Advances in nuclear analysis methods

Abstract

Recent developments in excitation, detection depth profiling and ultratrace analysis are discussed. On the topic of ultratrace analysis, the coupling of neutron activation followed by mass spectrometric detection of the activation products opens the possibility of determinations based on stable reaction products. The feasibility of neutron activation-mass spectrometry (NA-MS) has been demonstrated by its application to the determination of both ⁶Li(n,³H)⁴He and ¹⁰B(n,α)⁷Li. In the realm of depth profiling, resonant elastic scattering is a valuable tool for tracking ¹⁶O via ¹⁶O(α,α)¹⁶O with a depth resolution of 6 µg cm^–2. The technique of recoil-nucleus time-of-flight neutron depth profiling is discussed. The availability of cold neutron beams will result in a signal intensity increase of two or more orders of magnitude over thermal neutron beams. Hence cold neutron beams will enhance the capabilities of neutron capture, of prompt γ-ray activation analysis and of neutron depth profiling. Finally, heavy ion induced desorption with time-of-flight mass spectrometric detection of desorbed species presents a unique capability for the analysis of surfaces, mixtures and, in particular, large biomolecules.