1A. Non-Linear Least-Squares Fitting Techniques for Gamma Spectroscopy Part I
Sunday, March 23, 2025, 9-11 AM
A fundamentally-different and powerful method of HPGe spectral analysis will be described and demonstrated. Unlike conventional methods that begin with a search for peaks, a single, self-consistent function is fitted to all of the data in the spectrum, taken together as a single unit, using non-linear least-squares to find best fits for activities, calibrations, efficiencies, and attenuations. After a brief discussion of the mathematics of the method, a Windows program known as “VRF” that implements the method will be demonstrated with examples including in-situ uranium, persistent radio-pharmaceutical contaminants, and a prompt-gamma activation analysis. A free introductory version of VRF will be given to those who also attend Part II, so those who bring laptops can follow along with the examples.
Organizers: G. Lasche, Snakedance Scientific; C. Cray, Cray Consulting
1B. Non-Linear Least-Squares Fitting Techniques for Gamma Spectroscopy Part II
Sunday, March 23, 2025, 1-3 PM
Participants will be given a free introductory version of the VRF application for limited trial use afterwards with the included example spectra. Those who participated with Part I and bring a laptop will be able to follow along with analysis of examples during the workshop. Participants will also be introduced to advanced features of VRF including decay chain analysis, peak summing corrections, thermal neutron capture for PGAA, charged-particle reactions, non-equilibrium Bateman calculations, isotopic ratios, compounds and mixtures, imported efficiencies, batch processing, simulated spectra, decay during acquisition, decay since collection, report generation, user logging, adding or editing gamma sources, VRF Significance MDA, and more.
Organizers: G. Lasche, Snakedance Scientific; C. Cray, Cray Consulting