<p> The decay of 3.5 minute 89Kr to levels in 89Rb has been investigated with small and large volume Ge(Li) detectors used singly and in coincidence. A total of 160 gamma rays have been attributed to the nuclear process, 120 of which have been incorporated into a proposed decay scheme.</p> / Thesis / Master of Science (MSc)

Calculating or predicting the total in-core nuclear heating is a difficult tast. Full-core models can be constructed in a Monte Carlo code, such as MCNP6 or TRIPOLI4, and will allow an analyst to calculate the prompt-gamma heating at any given in-core location; however, such codes are generally unable to track the activated or fission-product isotopes and therefore the delayed-gamma sources can't be included in such a model. Some analysts have coupled Monte Carlo transport codes to burnup codes in an effort to include delayed-gamma sources, but the solutions tend to be reactor specific, time-independent and a lot of work. New ideas are required to calculate the total time-dependent in-core nuclear heating. Within this report, two new models have been derived: the nuclear heating equation, and the coupled neutron and nuclear heating point kinetics (NHPK) equations. These models can be used to calculate the time and position-dependent in-core heating. The nuclear heating equations are generalized expressions of the nuclear heating in a volume of interest, within an arbitrary geometry; these equations use Monte Carlo tallies as coefficients and treat the geometry's scalar neutron flux within as the independent variable. The NHPK model describes the nuclear heating in a volume of interest, within a critical assembly by coupling nuclear heating to the famous neutron point kinetics equations. A SCK-CEN gamma thermometer (GT) was commissioned in a materials testing reactor (MTR), the McMaster Nuclear Reactor (MNR), to measure the dynamic in-core nuclear heating in two locations. The nuclear heating equation was used to calculate self-heating of the SCK-CEN GT by neutron capture reactions. This calculation used CapGam and IAEA PGAA prompt-gamma emission data; delayed-particle emission data from NuDat 2.6 was also employed. Analysis of the GT's signal resulted in a quantitative description of the dynamic delayed-gamma heating in MNR, and provided the coefficients for the NHPK model. The NHPK model is capable of reproducing the measured time-dependent nuclear heating, and therefore should also be capable of predicting in-core nuclear heating as a function of reactor power. / Dissertation / Doctor of Philosophy (PhD)

<p> The polymerization of styrene initiated with gamma radiation as well as thermal initiation was studied at temperatures, 150, 155, 160, 165, 180 and 200C and dose rates of 0.072-0.1836 M Rads/hour. In all cases the reactions were studied up to 100% conversion and the following results were obtained. (1) Rate of polymerization was independent of dose rate. (2) 165C was considered to be the temperature at which the radiation polymerization system in the case of styrene reaches a limiting rate of initiation caused by high temperature and dose rate. (3) Self-production of ethynylbenzene in the system at 200C probably caused retardation of the initial rate of polymerization. (4) No significant gel effect was observed in the investigated temperature range. (5) Polystyrene produced by radiation at high temperatures has a very low average molecular weight. (6) A general mechanism was proposed based on the characteristics of the reactions. (7) A temperature range was proposed as an optimal reaction temperature for radiation polymerization of styrene. </p> / Thesis / Master of Engineering (MEngr)

The success of many experiments at rare-isotope facilities, such as the National Superconducting Cyclotron Laboratory (NSCL), depends on achieving a level of statistics that is partly driven by the overall number of nuclei produced in the beam. One such future study at the NSCL requires maximizing the beam content of 34mCl. To prepare for this 34mCl study, an initial measurement to determine the 34mCl yields and overall beam purity was performed at the NSCL by utilizing a Beta-decay experimental station. Isotopes delivered to the experimental station were identified using standard time of flight and energy loss techniques. To explore ways of maximizing 34mCl production, 6 different beam energy settings that selected different rigidities for isotopic selection and altered its entrance angles before the beam went into the fragment separator, were utilized. The absolute intensity of the peak energies associated with the decay of 34mCl (1177, 2127, and 3304 keV) were determined, as well as the overall number of 34Cl atoms delivered, thereby enabling 34mCl yield and beam purity determinations for each beam setting.

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