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Abstract  

The University of Texas (UT) at Austin has collaborated with the National Institute of Standards and Technology for comparisons of concentration versus depth profiles of samples containing 10B. Technology sharing from NIST has allowed UT to avoid many initial set backs such that significant advancements in the UT-NDP facility’s experimental and analytical methodology have been achieved. UT has analyzed two samples loaned to them from NIST. The collaborative effort between the two institutions has given the UT-NDP facility the proper tools to begin profiling more advanced samples in hopes of meeting the capabilities set by NIST in the NDP field. The UT-NDP facility was able to profile a borosilicate surface deposit onto silicon such that the concentrations of 10B at various depths of the deposit were determined and fit well to a Pearson distribution.

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Abstract  

Stainless steel flux wires were used to determine the neutron energy spectra and total flux during the Reactor Accelerator Coupling Experiments (RACE) at The University of Texas at Austin. A LINAC electron accelerator produced 20 MeV electrons at a power of 1.6 kW, which struck a tungsten-copper target to produce bremsstrahlung radiation and photoneutrons. The neutrons produced in the target were multiplied by the subcritical core of a Triga reactor. The purpose of the RACE experiments is to develop a sub-critical accelerator driven system that would be capable of transmuting actinides from spent fuel. Flux measurements were made with 1.58 mm diameter stainless steel wires placed throughout the core between the fuel rods and cadmium covered and uncovered gold and indium foils above the target. The MAXED and GRAVEL computer codes were used to perform the spectrum unfolding. The composition of the stainless steel wires was determined using neutron activation analysis with comparators prior to the flux measurement. The reactions measured in the stainless steel to determine the flux were 50Cr(n,γ)51Cr, 58Ni(n,p)58Co, 54Fe(n,p)54Mn, and 58Fe(n,γ)59Fe. Flux measurements agreed well with an MCNP simulation of the experiment.

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Summary  

Halides, particularly Br- and Cl-, have been used as indicators of potential sources of Na+ and Cl- in surface water and groundwater with limited success. Contamination of groundwater and surface water by Na+ and Cl- is a common occurrence in growing urban areas and adversely affects municipal and private water supplies in Illinois and other states, as well as vegetation in environmentally sensitive areas. Neutron activation analysis (NAA) can be effectively used to determine these halogens, but often the elevated concentrations of sodium and chlorine in water samples can give rise to very high detection limits for bromine and iodine due to elevated backgrounds from the activation process. We present a detailed analytical scheme to determine Cl, Br and I in aqueous samples with widely varying Na and Cl concentrations using epithermal NAA in conjunction with Compton suppression.

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Summary  

In the past few years there has been renewed worldwide interest in the re-establishment of various nuclear and radiochemistry disciplines in the hope of training the next generation of skilled researchers in this area. In the United States there continues to be an acute shortage of MSc and PhD level trained students, particularly at the Department of Energy national laboratories. As a result of this critical need the Department of Energy established a Radiochemistry Education Award Program (REAP) in the late 1990's to address this issue. Several universities were awarded funding to establish various complimentary programs. One of the main goals of the REAP at the University of Texas was to establish a web-based graduate level course with associated labs and to have interactions with the national laboratories.

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Abstract  

Neutron activation analysis was used to investigate and quantify the level of heavy metal uptake in the marine environment of Lake Austin in Austin, TX. Specifically, the samples studied were largemouth bass, or micropterus salmoides. The presence of heavy metals in the food chain presents multiple hazards, mostly as a food hazard for those species that ingest the fish, namely humans. To measure the concentrations of heavy metals in various fish samples, the nuclear analytical technique of neutron activation analysis (NAA) was used. Both epithermal and thermal irradiations were conducted for the NAA to look for short and long-lived radioisotopes, respectively. The samples themselves consisted of liver and tissue samples for each of the fish caught. Each sample was freeze-dried and homogenized before irradiation and spectrum acquisition. The results showed that all levels of heavy metals were not sufficient enough to make the fish unsafe for eating, with the highest levels being found for iron and zinc. Gold was found to be at much higher concentrations in the younger fish and virtually non-existent in the larger of the samples.

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Summary  

In the last decade Compton suppressed neutron activation analysis has had increasing popularity as a powerful method to significantly lower backgrounds and reduce overlapping peaks caused by spectral or nuclear interferences. We give a detailed descriptive evaluation of the unique features of this technique and its usefulness in many areas of research employing non-destructive neutron activation analysis.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: S. Landsberger, A. Plionis, S. Biegalski, K. Foltz-Biegalski, E. Schneider, D. O’Kelly, J. Braisted, S. O’Kelly, and L. Welch

Abstract  

Over the last three years we have developed a very robust nuclear and radiochemistry program at The University of Texas at Austin. The cornerstone of support was the DOE Radiochemistry Educational Award Program (REAP) that was awarded from 2002–2005. A second award for the period of 2005–2008 was just received. This award has enabled us to support many educational activities from vanguard classroom instruction, to laboratory enhancements, to research activities at the graduate and undergraduate levels. Both traditional radiochemistry and advanced topics in nuclear instrumentation have been supported. Various DOE university programs, national lab funding and IAEA fellowship grants, have allowed the Nuclear and Radiation Engineering Program at the University of Texas to be at the forefront of nuclear and radiochemistry educational and research activities and help secure the next generation of needed expertise.

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