Type: 
Senior Thesis Presentation
Date-Time: 
Thursday, May 24, 2018 - 14:00 to 15:00
Location: 
Johnson 102
Event Speaker: 
Abraham Teklu
Local Contact: 
Schellman
Abstract: 

Soon the largest fusion project in the world, ITER, will attempt to produce fusion power. The tokamak (a toroidal fusion device) being built in France will be running at such high temperatures that heat distribution is a problem. To prevent future calamity a tokamak run by General Atomics, Doublet III (DIII-D), is running experiments to modify the heat distribution in the divertor region; a narrow area on the floor of the tokamak. The resonant magnetic perturbations (RMPs) from 3D coils are varied to modify the splitting of the divertor strike points in DIII-D. This splitting is imaged in filtered visible and infrared emission to determine the particle and heat flux patterns on the target plates. The observed splitting is compared to vacuum modeling in dis- charges where a subset of the RMP coils were ramped to shift the divertor footprints from dominantly n = 3 to n = 2 pattern. The measured splitting has a very similar pattern to the modeled splitting, but is on a scale that is 5 times larger. These results could later be used to determine if the plasma response model can be validated with the measured splitting seen in the camera data. The sensitivity of the modeled splitting seems to depend on details of the 2D equilibrium. Models with a kinetic equilibrium seem to have a better fit at later timeslices, but no significant improvement from mod- els with a magnetics only equilibrium for earlier timeslices. This RMP ramp technique could be used in ITER to spread out the heat flux while avoiding excessive forces on the RMP coils. *Work supported by U.S. DOE under the Science Undergraduate Lab- oratory Internship (SULI) program and DE-FC02-04ER54698, DE-FG02-07ER54917, DE-FG02-05ER54809 and DE-AC52-07NA2734

Abraham Teklu is a student in the Honors College.