Abstract: A method is provided for simplifying the calibration of neutron multiplicity counters. The method includes multiplicity counter dead time correction algorithms that preclude the need for extended calibration steps with known radiation sources. The algorithms include approximations that allow calculation of the counter's efficiency without knowledge of sample source activity or origin.

Abstract: A method is provided for simplifying the calibration of neutron multiplicity counters. The method includes multiplicity counter dead time correction algorithms that preclude the need for extended calibration steps with known radiation sources. The algorithms include approximations that allow calculation of the counter's efficiency without knowledge of sample source activity or origin.

Abstract: A method for automating and extending the density range for gamma ray attenuation correction algorithms for all classes of non-destructive assay systems including those without automated shutters or automated collimators. A system and software for implementing the method are also provided. The system features a dual-intensity transmission source and utilizes a three pass scanning protocol. The high-energy source in conjunction with a beam modulator produces a high and low energy beam. Automated software determines which beam data to use in tomographic reconstruction of an object being scanned.

Abstract: In a preferred embodiment, a method of enhancing the neutron coincidence assay of low fissile mass samples, by combining assay precision improvement algorithms with novel background and matrix correction algorithms, to provide lower levels of detection with higher confidence that the reported results are not subject to biases resulting from environmental or sample matrix effects.