Research

The following article first appeared as David C. Pace, William W. Heidbrink, and Michael A. Van Zeeland, “Keeping Fusion Plasmas Hot,” Physics Today 68, 34 (2015). In the article, we discuss interactions between high energy ions and electromagnetic waves in magnetically confined plasmas. These plasmas are produced in nuclear fusion reactors known as tokamaks. My 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. […]