학술논문

Recent EAST Experimental Results and Systems Upgrade in Support of Long-Pulse Steady-State Plasma Operation
Document Type
Periodical
Source
IEEE Transactions on Plasma Science IEEE Trans. Plasma Sci. Plasma Science, IEEE Transactions on. 50(11):4330-4334 Nov, 2022
Subject
Engineered Materials, Dielectrics and Plasmas
Fields, Waves and Electromagnetics
Plasmas
Heating systems
Antennas
Couplings
Steady-state
Particle beam injection
Cyclotrons
EAST
experimental data
long-pulse steady-state plasma operation (SSO)
systems upgrade
Language
ISSN
0093-3813
1939-9375
Abstract
In recent years, EAST has achieved a 60-s scale steady-state plasma operation (SSO), which is electron dominant heated by the electron cyclotron wave and low hybrid wave. Substantial progresses have been made in the development of long-pulse operation, such as active control of radiative divertor, edge localized mode (ELM) suppression, and He plasma experiment. To further develop the steady-state operation scenario and study the related critical physical issues, the upgrade of EAST has been completed in 2020. The auxiliary heating systems were rearranged and upgraded with a total heating power capability of 33 MW. The 2.45-GHz lower hybrid current drive (LHCD) launcher has been updated from full active multijunction (FAM) to passive active multijunction (PAM) to avoid damage caused by plasma–material interaction. The injection power capability of electron cyclotron resonance heating (ECRH) system is upgraded to 1.4 MW. The upgraded ion cyclotron resonance frequency (ICRF) antenna injects low parallel wavenumber ( $k_{\vert \vert }$ ) spectra with good single pass absorption. The neutral beam injection (NBI) system is moved from F-port to D-port and is reoriented from counterclockwise to clockwise injection. The armor material of lower divertor has been upgraded from graphite to tungsten improving the steady-state heat handling capability from 2 to 10 MW/m2. Based on the upgraded pumping system and improved conductance, the effective pumping speed for $D_{2}$ of the EAST lower divertor increased twice. With all these upgrades, 100-s scale steady-state operation ( $T_{e0} >10$ keV) and 1056-s high-performance operation with 1.73-GJ injection energy were achieved in 2021 campaigns. The experience in high-performance long-pulse operation obtained on EAST will lay a foundation for the ITER and Chinese Fusion Engineering Testing Reactor (CFETR) operation.