Student: Vincent Graber
Project: Control-Oriented Core-SOL-Divertor Model for Integrated Burn and Divertor Control in ITER
View: Research Poster (PDF) | Presentation (YouTube)
Department: Mechanical Engineering and Mechanics
Advisor: Eugenio Schuster
Abstract
Burn control in ITER will require careful regulation of the core-plasma’s density and temperature while guaranteeing safe operation of the divertor. Satisfying performance objectives in the plasma core is challenging due to the core’s sensitivity to both the conditions and the requirements in the scrape-off-layer (SOL) and divertor regions. First, SOL-divertor conditions determine the strength to which deuterium-tritium recycling fuels the core. This could be particularly important in ITER where there might be limits on the level of tritium that can be supplied externally. Second, the SOL-divertor conditions prescribe the intensity to which intrinsic impurities (W and He) and puffed impurities (needed to achieve detachment) pollute the plasma core. Third, the ability to maintain some level of detachment depends strongly on the separatrix density and the power flowing into the SOL from the core. Clearly, core-control objectives will need to be balanced with divertor-control objectives. In this work, the phenomena outlined above are described by using a control-oriented core-SOL-divertor model. The model consists of three components: (1) the energy and density transport equations of the core-plasma, (2) neutral particle balances in the divertor region, and (3) a two-point model that relates the plasma conditions at some upstream separatrix position to that at the divertor target. Using this core-SOL-divertor model, the coupled burn and divertor control challenges faced by ITER can be investigated.
About Vincent Graber
Vincent Graber is a Ph.D. candidate in mechanical engineering and mechanics, and he is a member of Lehigh University’s Plasma Control Group. Dr. Eugenio Schuster, a professor in Lehigh University’s P.C. Rossin College of Engineering and Applied Science, heads the Plasma Control Group, and he is Vincent’s academic advisor. Their research focuses on the control of burning plasmas in devices called tokamaks. Burning plasmas are ionized gases that produce fusion. Tokamaks can confine these extremely hot plasmas by applying magnetic fields. Vincent and Professor Schuster have authored papers for the 58th IEEE Conference on Decision and Control, 2020 American Control Conference and more. Under the Department of Energy’s Office of Science Graduate Student Research program, they are currently working on a research proposal with Princeton Plasma Physics Laboratory (PPPL) scientist Dr. Dan Boyer. The research project seeks to assess burn controllers in closed loop with PPPL’s plasma transport code (TRANSP).