Research

This paper means a lot to me. It has both a technical side and an emotional side. The physics of this paper concerns how small scale turbulent fluctuations in the plasma (e.g., fluctuations of the plasma density) can affect the way that energetic ions move across the magnetic field. Fundamentally, the orbit size of these […]

This paper describes the Fast Ion Loss Detector (FILD) at the Alcator C-Mod tokamak. The FILD captures ions that are accelerated to high energies due to radio wave power injection into C-Mod. A couple of neat things about this diagnostic are that it is made of the same molybdenum material as the walls in C-Mod, and […]

This paper describes observations of injected radio wave power getting absorbed by edge ions in the DIII-D tokamak. It’s a valuable observation because we inject those radio waves in order to heat the plasma more towards the center of the tokamak, so if some of that energy gets absorbed by particles in the far edge, then […]

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 […]

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. […]

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. […]