Optimization of the Prompt Gamma Site at the McMaster Nuclear Reactor for in Vivo Neutron Activation Analysis

Abstract

<p> This work was the first study at the beam port # 4 at the McMaster Nuclear Reactor, involving prompt gamma in vivo neutron activation analysis. The project consisted of experimental and computational parts. The computational part was done using MCNP program, which simulates the neutron and photon transport in the medium. The first thing assessed was the energy dependent neutron fluence rate in the collimated neutron beam, at the site. This was done in order to figure out the complete source (sdef) card for further MCNP calculations. This was combined experimental and computational work. For the experimental part, various activation foils were used and computational part was done by using MCNP programming.</p> <p> The second part of the project involved experimental prompt gamma in vivo activation analysis using 7 different phantoms, ranging from 30 mL to 2 L. Three different elements were observed. The prompt gamma in vivo detection of cadmium was the preliminary calibration study and the experiments were done with all seven phantoms. The calibration lines and MDL were assessed for all phantoms, with concentration ranging from 0 to 50 ppm. The prompt gamma in vivo detection of boron and mercury was done using 30 mL phantoms. Calibration lines and MDL for both elements were assessed as well.</p> <p> MCNP experimental simulations for 30 mL water phantoms were done and they were in close agreement with the experimental results. Furthermore, the MCNP gamma and neutron dose survey in the cave was done.</p> <p> The results obtained showed that there are numerous open possibilities for improvement in terms of in vivo prompt gamma analysis at the site. It predominantly includes the improvements in prompt gamma detection techniques and MCNP source definition. Furthermore, it was found that MCNP programming is the ideal tool for assessment and control of the experimental results in this case. It means that in the future research, the MCNP modeling will be the essential part of the in vivo prompt gamma activation analysis at this beam port.</p>