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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
BEGIN:VEVENT
SEQUENCE:0
UID:UW-Physics-Event-3512
DTSTART:20141110T180000Z
DTEND:20141110T190000Z
DTSTAMP:20260416T144438Z
LAST-MODIFIED:20141106T160148Z
LOCATION:2535 Engineering Hall
SUMMARY:3D Modeling of RF Antennas\, Sheaths\, and Slow Waves in Time 
 Domain\, Plasma Physics (Physics/ECE/NE 922) Seminar\, David Smithe\, 
 Tech-X Corporation
DESCRIPTION: <br>
\nFinite difference time domain simulation tools off
 er unique capability for the study of RF antennas in fusion-scale expe
 riments\, because of their traditional focus on accurate detailed repr
 esentation of 3D geometry.<br>
\n<br>
\nThis talk will present our eff
 orts to apply such a code to the modeling of antennas on MST\, NSTX\, 
 CMod\, and ITER. RF sheaths on or near the antenna are believed to be 
 responsible for impurity production\, a major concern for fusion exper
 iments.  These same sheath effects are also key to producing non-therm
 al electron populations which maintain ionization in some industrial p
 lasmas.<br>
\nThe talk will show how we use sub-grid models to represe
 nt the RF and rectified sheath\, and how we plan to combine this with 
 test particles to model non-thermal physics.  Finally\, while performi
 ng such simulations\, an observation of strong slow-wave excitation in
  a thin layer near the antenna has also led to questions of whether su
 ch waves might be a contributor to parasitic losses from these antenna
 s\, e.g.\, in NSTX.  The talk will discuss this hypothesis\, and on-go
 ing modeling efforts aimed at better understanding it.<br>
\n
URL:https://www.physics.wisc.edu/events/?id=3512
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