This research project was to improve the prompt gamma-ray neutron activation analysis (PGNAA) measurement approach for bulk analysis, oil well logging, and small sample thermal enutron bean applications.

Prompt gamma activation analysis (PGAA) is a unique, non-destructive nuclear analytical method with multi-element capabilities. It is most effective if intense neutron beams (especially cold beams) of nuclear reactors are used to induce the prompt gamma radiation. Based largely on the authors' pioneering research in cold neutron PGAA, the handbook describes the methodology in self-contained manner and reviews recent applications. The library of prompt gamma ray data and spectra for all natural elements is a unique aid to the practitioner. The level is understandable by a broad audience, which facilitates teaching and training. The Handbook of Prompt Gamma Activation Analysis is a comprehensive handbook written for those practising the method, wanting to implement it at a reactor facility, or just looking for a powerful non-destructive method of element analysis. The book is also useful for nuclear physics, chemistry and engineering scientists, scholars and graduate students interested in neutron-induced gamma ray spectroscopy and nuclear analytical methods.

Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) offers a non-destructive, relatively rapid on-line method for determination of elemental composition of bulk and other samples. However, PGNAA has an inherently large background. These backgrounds are primarily due to the presence of the neutron excitation source. It also includes neutron activation of the detector and the prompt gamma rays from the structure materials of PGNAA devices. These large backgrounds limit the sensitivity and accuracy of PGNAA. Since Most of the prompt gamma rays from the same element are emitted in coincidence, a possible approach for further improvement is to change the traditional PGNAA detection technique and introduce the gamma-gamma coincidence technique. It is well known that the coincidence technique can eliminate most of the interference backgrounds and improve the signal-to-noise ratio. A new Monte Carlo code CEARCPG is being developed at CEAR to predict coincidence counting in coincidence PGNAA. Compared to the other existing Monte Carlo code, a new algorithm of sampling the prompt gamma rays, which are produced from neutron capture reaction and neutron inelastic scattering reaction, is developed in this work. All the prompt gamma rays are taken into account by using this new algorithm. Before this work, the commonly used method is to interpolate the prompt gamma rays from the pre-calculated gamma-ray table. It works fine for the single spectrum. However it limits the capability to simulate the coincidence spectrum. This new algorithm is to sample the prompt gamma rays from the nucleus scheme. It makes possible to simulate the coincidence spectrum by using Monte Carlo method. The primary nuclear data library used to sample the prompt gamma rays comes from ENSDF library. Three cases are simulated and the simulated results are checked with the experiments. The first case is the prototype for ETI PGNAA application. This case is designed to check the capability of CEARCPG for sing.

Neutron-capture prompt-gamma activation analysis (PGAA) is particularly valuable as a non-destructive nuclear method in the measurement of elements that do not form neutron capture products with delayed gamma ray emissions. Inaccurate and incomplete data have been a significant hindrance in the qualitative and quantitative analysis of complicated capture gamma spectra by means of PGAA. This database was produced to improve the quality and quantity of required data in order to make possible the reliable application of PGAA in fields such as materials science, geology, mining, archaeology, environment, food analysis and medicine. The database provides a variety of tables for all natural elements (from H to U) including the following data: isotopic composition, thermal radiative cross-section (total and partial), Westcott g-factors, energy of the gamma rays (prompt and delayed), decay mode, half-life and branching ratios. The CD-ROM included in this publication contains the database, the retrieval system and important electronic documents related to the project.--Publisher's description.

In this work a prompt gamma neutron activation analysis (PGNAA) facility has been designed, built, and characterized at the Oregon State University TRIGA® reactor. PGNAA is a technique used to determine the presence and quantity of trace elements such as boron, hydrogen and carbon which are more difficult to detect with other neutron analysis methods. In PGNAA, isotopes are subjected to a neutron beam, resulting in the formation of an unstable compound nucleus. The compound nucleus immediately decays, producing a series of gamma-rays, whose energies are distinctive to each element. These gamma-rays are then measured using an HPGe detector to determine the elemental composition of the sample. The measured thermal and epithermal neutron fluxes of the PGNAA facility at Oregon State University are 2.81 x 107 ± 5.13 x 105 cm−2s−1 and 1.70 x 104 ± 3.11 x 102 cm−2s−1 respectively. This gives the facility a cadmium ratio of 106. Measured detection limits for boron, chlorine, and potassium in SRM 1571 orchard leaf standard were, 5.6 x 10−4mg/g, 8.2 x 10−2 mg/g and, 1.0 mg/g respectively. Also, the detection limit for hydrogen in high-density polyethylene is, 6.8 x 10−2mg/g. Detection limits for additional elements are presented in this work.

The normal prompt gamma-ray neutron activation analysis for either bulk or small beam samples inherently has a small signal-to-noise (S/N) ratio due primarily to the neutron source being present while the sample signal is being obtained. Coincidence counting offers the possibility of greatly reducing or eliminating the noise generated by the neutron source. The present report presents our results to date on implementing the coincidence counting PGNAA approach. We conclude that coincidence PGNAA yields: (1) a larger signal-to-noise (S/N) ratio, (2) more information (and therefore better accuracy) from essentially the same experiment when sophisticated coincidence electronics are used that can yield singles and coincidences simultaneously, and (3) a reduced (one or two orders of magnitude) signal from essentially the same experiment. In future work we will concentrate on: (1) modifying the existing CEARPGS Monte Carlo code to incorporate coincidence counting, (2) obtaining coincidence schemes for 18 or 20 of the common elements in coal and cement, and (3) optimizing the design of a PGNAA coincidence system for the bulk analysis of coal.