CORE
🇺🇦
make metadata, not war
Services
Services overview
Explore all CORE services
Access to raw data
API
Dataset
FastSync
Content discovery
Recommender
Discovery
OAI identifiers
OAI Resolver
Managing content
Dashboard
Bespoke contracts
Consultancy services
Support us
Support us
Membership
Sponsorship
Community governance
Advisory Board
Board of supporters
Research network
About
About us
Our mission
Team
Blog
FAQs
Contact us
Off-axis neutral beam current drive for advanced scenario development in DIII-D
Authors
PM Anderson
ME Austin
+33 more
NH Brooks
RV Budny
CD Challis
JC Deboo
JS Degrassie
JR Ferron
P Gohil
WW Heidbrink
J Hobirk
CT Holcomb
EM Hollmann
RM Hong
AW Hyatt
MJ Lanctot
J Lohr
TC Luce
MA Makowski
DC McCune
M Murakami
TH Osborne
JM Park
CC Petty
PA Politzer
R Prater
JT Scoville
HE St John
T Suzuki
TS Taylor
EA Unterberg
MA Van Zeeland
MR Wade
WP West
JH Yu
Publication date
6 July 2009
Publisher
eScholarship, University of California
Abstract
Modification of the two existing DIII-D neutral beamlines is planned to allow vertical steering to provide off-axis neutral beam current drive (NBCD) peaked as far off-axis as half the plasma minor radius. New calculations for a downward-steered beam indicate strong current drive with good localization off-axis so long as the toroidal magnetic field, BT, and the plasma current, Ip, point in the same direction. This is due to good alignment of neutral beam injection (NBI) with the local pitch of the magnetic field lines. This model has been tested experimentally on DIII-D by injecting equatorially mounted NBs into reduced size plasmas that are vertically displaced with respect to the vessel midplane. The existence of off-axis NBCD is evident in the changes seen in sawtooth behaviour in the internal inductance. By shifting the plasma upwards or downwards, or by changing the sign of the toroidal field, off-axis NBCD profiles measured with motional Stark effect data and internal loop voltage show a difference in amplitude (40-45%) consistent with differences predicted by the changed NBI alignment with respect to the helicity of the magnetic field lines. The effects of NBI direction relative to field line helicity can be large even in ITER: off-axis NBCD can be increased by more than 30% if the BT direction is reversed. Modification of the DIII-D NB system will strongly support scenario development for ITER and future tokamaks as well as provide flexible scientific tools for understanding transport, energetic particles and heating and current drive. © 2009 IAEA, Vienna
Similar works
Full text
Available Versions
Sustaining member
eScholarship - University of California
See this paper in CORE
Go to the repository landing page
Download from data provider
oai:escholarship.org:ark:/1303...
Last time updated on 25/12/2021