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New observations at the DIII-D National Fusion Facility offer vital insights into energetic ions in fusion plasmas, key for fusion power development and space DIII-D National Fusion Facility provide the first direct observations of energetic ions moving through space and energy in a tokamak. Researchers combined these measurements with advanced computer models of electromagnetic waves and how they interact with energetic ions. The results provide an improved understanding of the interplay between plasma waves and energetic ions in fusion plasmas.
Advancements in Fusion Research and Practical Applications
Plasma physics and fusion research are moving from experimental facilities toward demonstration power plant designs. To make this move a success, researchers need accurate simulations and other tools that predict how power plant designs will perform. Most current facilities do not produce burning plasmas. However, researchers understand much of the relevant physics and are developing simulations to reproduce observed experimental behavior.
The current research made new measurements of energetic ion flow in the DIII-D tokamak. This will accelerate the development of models that account for all relevant wave-ion interaction dynamics.
This improved understanding also allows for the application of phase-space engineering. Researchers can use this process to design new fusion plasma scenarios based on predicted ideal interactions between waves and ions. Notably, these interactions can also impair satellites, so this research may help improve their reliability.
Innovations at the DIII-D National Fusion Facility
Researchers at the DIII-D National Fusion Facility, a Department of Energy user facility, have used the first measurements from a new diagnostic system, the Imaging Neutral Particle Analyzer (INPA), to observe the flow of energetic ions in a tokamak. A multi-year effort to conceptualize, design, and build the INPA has now provided the first-ever capability to observe this behavior.
After being injected into the tokamak by neutral beams, energetic ions interact with electromagnetic plasma waves and flow in energy and position through the tokamak. Simulations reproduce the observed behavior, thereby demonstrating the DOI: 10.1088/1741-4326/acbec5
“Modelling the Alfvén eigenmode induced fast-ion flow measured by an imaging neutral particle analyzer” by J. Gonzalez-Martin, X.D. Du, W.W. Heidbrink, M.A. Van Zeeland, K. Särkimäki, A. Snicker, X. Wang and Y. Todo, 29 September 2022, Nuclear Fusion.
DOI: 10.1088/1741-4326/ac7406
“Visualization of Fast Ion Phase-Space Flow Driven by Alfvén Instabilities” by X. D. Du, M. A. Van Zeeland, W. W. Heidbrink, J. Gonzalez-Martin, K. Särkimäki, A. Snicker, D. Lin, C. S. Collins, M. E. Austin, G. R. McKee, Z. Yan, Y. Todo and W. Wu, 1 December 2021, DOI: 10.1103/PhysRevLett.127.235002
This work was supported by the Department of Energy (DOE) Office of Science, Office of Fusion Energy Sciences, using the DIII-D National Fusion Facility, a DOE Office of Science user facility.