Reaching High Poloidal Beta at Greenwald Density with Internal Transport Barrier Close to Full Noninductive Current Drive

J. Hobirk; R. C. Wolf; O. Gruber; A. Gude; S. Günter; B. Kurzan; M. Maraschek; P. J. McCarthy; H. Meister; A. G. Peeters; G. V. Pereverzev; J. Stober; W. Treutterer; ASDEX Upgrade Team

doi:10.1103/PhysRevLett.87.085002

Reaching High Poloidal Beta at Greenwald Density with Internal Transport Barrier Close to Full Noninductive Current Drive

J. Hobirk, R. C. Wolf, O. Gruber, A. Gude, S. Günter, B. Kurzan, M. Maraschek, P. J. McCarthy, H. Meister, A. G. Peeters, G. V. Pereverzev, J. Stober, W. Treutterer, and ASDEX Upgrade Team

Phys. Rev. Lett. 87, 085002 – Published 2 August 2001

Abstract

In the ASDEX Upgrade tokamak, high poloidal beta up to $β_{pol} = 3$ at the Greenwald density with H-mode confinement has been reached. Because of the high beta, the plasma current is driven almost fully noninductively, consisting of $51 %$ bootstrap and $43 %$ neutral beam driven current. To reach these conditions the discharge is operated at low plasma current ( $I_{P} = 400 kA$ ) and high neutral beam heating power ( $P_{NBI} = 10 MW$ ). The discharge combines an edge (H mode) and internal transport barrier at high densities without confinement-limiting MHD activities. The extrapolation to higher plasma currents may offer a promising way for an advanced scenario based fusion reactor.

Received 16 April 2001

DOI:https://doi.org/10.1103/PhysRevLett.87.085002

Authors & Affiliations

J. Hobirk¹, R. C. Wolf¹, O. Gruber¹, A. Gude¹, S. Günter¹, B. Kurzan¹, M. Maraschek¹, P. J. McCarthy², H. Meister¹, A. G. Peeters¹, G. V. Pereverzev¹, J. Stober¹, W. Treutterer¹, and ASDEX Upgrade Team¹

¹Max-Planck-Institut für Plasmaphysik, EURATOM Association, Boltzmannstrasse 2, D-85748 Garching, Germany
²Physics Department, University College Cork, Association Euratom-DCU, Cork, Ireland