Browsing by Author "M. Bourham, Committee Member"

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Advanced Thermosyphon Targets for Production of the 18F Radionuclide.
(2007-03-26) Stokely, Matthew Hughes; M. Shearer, Committee Member; G. Bida, Committee Member; B. Wieland, Committee Member; J. Michael Doster, Committee Chair; M. Bourham, Committee Member
Single phase and boiling batch water targets are the most common designs for the cyclotron production of 18F via the 18O(p,n)18F reaction. Thermosyphon targets have design and operating characteristics which enables higher power operation than conventional boiling targets of like size. Experiments and calculations were performed in order to characterize the performance of a 1.3 cc tantalum [18F]Target. The test target led to the development of a variety of computational techniques as well as experimental methods that will be used in future target design and optimization. Computational methods include several applications of Monte Carlo Radiation Transport as well as Finite Element Analysis. In addition, experimental thermal hydraulic and radiochemical analyses were performed.
Deployment, Testing and Analysis of Advanced Thermosyphon Target Systems for Production of Aqueous [18F]Fluoride via 18O(p,n)18F
(2008-07-10) Stokely, Matthew Hughes; Bruce Wieland, Committee Member; M. Bourham, Committee Member; Gerald Bida, Committee Member; Michael Shearer, Committee Member; J. Michael Doster, Committee Chair
High Capacity Heat Exchangers for Recirculating 18F Radionuclide Production Targets
(2007-03-28) Newnam, Robert Pruett; J.M. Doster, Committee Chair; T. Gerig, Committee Member; M. Haider, Committee Member; B. Wieland, Committee Member; M. Bourham, Committee Member
North Carolina State University in conjunction with Bruce Technologies Inc. is developing recirculating water targets for the cyclotron production of high yields of 18F fluoride for PET radiopharmaceuticals. Flourine-18 is commonly produced through proton irradiation of 18O enriched water by the 18O(p,n)18F reaction. Heat deposited in the target fluid by the proton beam is proportional to the 18F produced, thus production is often limited by the targets ability to reject heat. For power levels above 3 kW, boiling batch targets with local cooling can become impractical due to excessive 18O water volumes. One potential solution is a recirculating target system where the target water velocity is sufficient to prevent boiling. In this design the heated fluid travels through an external heat exchanger of sufficient capacity to remove the heat, and then through a pump which returns the cooled fluid to the target. A high-flow/low-volume pump and a high-capacity/low-volume heat exchanger are essential to the overall performance of the recirculating target. In this work, two different types of heat exchangers are considered. Laboratory testing was conducted on a small shell and tube heat exchanger that removed nearly 6 kW of heat at flows provided by a miniature regenerative turbine pump. Laboratory testing was also conducted on a small cross flow heat exchanger with measured performance of 7.4 kW and predicted peak performance approaching 10 kW.
A New Method for Radioactive Particle Tracking
(2005-12-08) Shehata, Ashraf Hassan; R. P. Gardner, Committee Chair; A. Hawary, Committee Member; M. Bourham, Committee Member; Geir Johanson, Committee Member; K. L. Murty, Committee Member
A system based on the concept of three detectors radio active particle tracking, to track a particle non-invasively in the three dimensions is presented. It consists of a set of three well collimated detectors mounted on a platform that can be moved to track the radioactive particle vertically through one collimated detector with a horizontal slot opening. The other two collimated detectors with vertical slot opening can be rotated angularly to track the radioactive particle in the planar domain, and deduce the polar coordinates. A complete description of the actual system developed is outlined including the hardware, the automation and control software, and the data acquisition aspects. A critique of the conventional tomographic radioactive particle tracking was established in comparison to the new three detectors system we developed. A number of obvious and valuable advantages of the new method were pointed out. The result presented here are illustrative through a series of benchmark experiments to test and verify the performance of the system. Results of real trajectories of a single radioactive particle moving in air, and in a bed filled with a mass of granular spherical attenuating medium is also presented. Through testing benchmark experiments that include a variety of real time trajectories the success of the tracking system is demonstrated.