This paper discusses three different plasma phenomena that lead to transport of beam ions in tokamaks. The material was first presented as an invited talk at the 23rd IAEA Fusion Energy Conference in Daejon, Republic of Korea in 2010. That IAEA meeting is held every two years and it represents the largest (most important?) fusion-specific […]
Research
Convective beam ion losses due to Alfven eigenmodes in DIII-D reversed-shear plasmas
This paper presents the first observations of coherent beam ion losses due to plasma waves in the DIII-D tokamak. The actual measurement is the flux of beam ions that hit a probe located at the outer wall. That diagnostic, the Fast Ion Loss Detector (FILD), was built as part of a collaboration with the ASDEX Upgrade tokamak. […]
Modeling the Response of a Fast Ion Loss Detector Using Orbit Tracing Techniques in a Neutral Beam Prompt Loss Study on the DIII-D Tokamak
This paper details a method for correlating measurements of beam ion losses with the injection of individual beams in the DIII-D tokamak. This turns out to be a great tool for making sense of the measurements. The probe measures ion impacts, and then we use particle orbit calculations to backtrack the ions to specific beams. […]
Exponential Frequency Spectrum in Magnetized Plasmas
This paper represents the main result from my Ph.D. Thesis: power spectra with exponential dependencies in frequency (semilog format) can be caused by Lorentzian shaped pulses in the time series of the measured fluctuating quantity. Knowing this can provide a big step in the understanding of how transport processes evolve in a plasma, for example, […]
Spontaneous Thermal Waves in a Magnetized Plasma
This paper holds a special place in my heart as my very first primary-author paper. It was also very fun to write because the observation (discovery!) was not an intended goal of my Ph.D. thesis project. My thesis was about wave fluctuations in a tiny plasma filament. Along the way, however, I found that there […]