51st Annual Meeting of the APS Division of Plasma Physics
Volume 54, Number 15
Monday–Friday, November 2–6, 2009;
Atlanta, Georgia
Session MR1: Review: Physics Progress of Reversed Field Pinch Magnetic Confinement
8:00 AM–9:00 AM,
Wednesday, November 4, 2009
Room: Centennial I-II
Chair: Stewart Prager, Princeton Plasma Physics Laboratory
Abstract ID: BAPS.2009.DPP.MR1.1
Abstract: MR1.00001 : Physics progress of Reversed Field Pinch magnetic confinement
8:00 AM–9:00 AM
Preview Abstract
Author:
John S. Sarff
(University of Wisconsin-Madison)
Over the last decade, the international RFP community has made
large strides understanding key physics challenges for plasma
confinement with weak external magnetization. This progress
fundamentally changes the fusion outlook for the RFP. In several
areas, resolving the RFP's fusion challenges is simultaneously
advancing basic plasma physics, with potentially large impact in
astrophysics. For example, the magnetic dynamo in the RFP reveals
how large-scale instabilities can efficiently transport magnetic
energy. An understanding of MHD tearing that supports dynamo
action inspired current profile control. This produces a ten-fold
improvement in confinement, comparable to a same-size,
same-current tokamak. A recent push to higher plasma current
reveals remarkable self-organization to a helical equilibrium, or
quasi-single-helicity dynamo state, that also exhibits improved
confinement. These controlled and spontaneous transitions from
high to low levels of magnetic chaos probe transport in a
stochastic magnetic field, the natural state of the field in
astrophysical settings. High temperature ions $>$1 keV are
observed, heated during magnetic reconnection events. This is
reminiscent of non-collisonal heating in the solar atmosphere.
Coupled with current profile control, improved confinement with
multi-kilovolt temperature electrons and ions is demonstrated.
Active control of the magnetic boundary is now routine to
stabilize many resistive wall modes in pulse lengths $>$10 times
their growth rate, an essential need for the RFP and likely other
high beta configurations. Few options exist for steady-state
current sustainment in fusion plasmas. One is Oscillating Field
Current Drive, based on magnetic helicity conservation principles
that underpin magnetic self-organization. Partial OFCD
sustainment experiments so far agree with the self-organization
physics basis. This work is supported by the US DOE and NSF.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2009.DPP.MR1.1