Doctoral Dissertation Defense by Ramona Perez

Event information


Designs for future nuclear fusion power reactors rely on the ability to create a stable plasma (hot ionized gas of hydrogen isotopes) as a medium with which to sustain nuclear fusion reactions. My dissertation work involves designing, constructing, testing, installing, operating, and validating a new diagnostic for spherical tokamaks, a type of reactor test facility. Through detecting charged particles emitted from the plasma, this instrument can quantitatively assess nuclear fusion reaction rates at specific locations inside the plasma and as a function of time. This can provide valuable data that can be used to evaluate theory-based simulations related to energy transport and plasma stability.

The Proton Detector (PD), installed in the Mega Amp Spherical Tokamak (MAST) at the Culhame Centre for Fusion Energy (CCFE) in Abingdon, England, was the first instrument to experimentally detect 3 MeV Protons and 1 MeV Tritons created from Deuterium-Deuterium (hydrogen isotopes) nuclear fusion reactions inside a spherical tokamak's plasma. It was installed in MAST and data were collected over a period of two months in the summer of 2013. Proton and triton particle production rates as high as 200 kHz were measured and initial distributions of the density of these particle production rates inside the plasma were extracted.

These results will be compared to a complementary instrument at MAST as well as theory-based simulations and form the knowledge basis for developing a larger future instrument. The design and performance of all instrument components (electrical, computational, mechanical), and subsequent data analysis methods and results will be discussed.