<< December 2020 >>
Sun Mon Tue Wed Thu Fri Sat
   1   2   3   4   5 
 6   7   8   9   10   11   12 
 13   14   15   16   17   18   19 
 20   21   22   23   24   25   26 
 27   28   29   30   31   
Add an Event

Plasma Physics (Physics/ECE/NE 922) Seminars

<< Summer 2020 Fall 2020 Spring 2021 >>
Subscribe to receive email announcements of events

Events During the Week of December 6th through December 13th, 2020

Monday, December 7th, 2020

Demonstration of helium exhaust enhancement during resonant magnetic perturbation (RMP) field application at DIII-D
Time: 12:00 pm
Place: Zoom Meeting
Speaker: Edward Hinson, UW Engineering Physics department
Abstract: It is shown for the first time in a diverted tokamak that
key metrics for continuous fusion, effective helium particle
confinement time, 𝛕_p*He, and its ratio with energy confinement,
𝛕_p*He/𝛕_E, were reduced by a factor of 2-3 during suppression of
edge localized modes (ELMs) by resonant magnetic field perturbations
(RMPs) over the unperturbed ELMy case. Reduced 𝛕_p*He during RMP was
observed in the core, edge, and pump plenum, where higher helium
pressure and concentration were also found. Elevated ionized helium
line emission during ELM suppression, with a decay time matching
𝛕_p*He, was measured at the inner strike point, suggesting more
helium in the unconfined region. These observations suggest that
processes during application of RMPs better retain helium at the edge,
in excess of that expected from deuterium ‘pumpout,’ where it is
pumped more quickly. A multi-reservoir model, derived from a finite
volume approximation of the continuity equation with diffusive and
convective transport, fits the helium time evolution at each of the
above-mentioned measurements well. Transport parameters obtained from
these fits indicate the data are consistent with strongly increased
transport of helium in the separatrix region during RMP application,
although higher core transport is also found. These findings, which
were obtained in ITER-shaped plasmas, provide evidence that
application of RMP ELM suppression in future devices such as ITER may
be capable of matching or exceeding the helium impurity exhaust
produced by the ELM events themselves, thereby helping to avoid helium
ash buildup in a burning regime, and maintain high fusion gain.

Connection information:

Join Zoom Meeting

Meeting ID: 991 5610 7574
Passcode: 883688
Host: Paul Terry
Add this event to your calendar

Tuesday, December 8th, 2020

No events scheduled

Wednesday, December 9th, 2020

No events scheduled

Thursday, December 10th, 2020

No events scheduled

Friday, December 11th, 2020

No events scheduled

©2013 Board of Regents of the University of Wisconsin System