HL -2A Experimental Scenarios for 2006

      Research Areas

l      Confinement, transport & turbulence

l      MHD instabilities, disruption & its mitigation

l      Radio-frequency heating & current drive

l      Boundary and divertor physics

1.  Confinement, transport & turbulence

Long-term goal is to develop a predictive understanding of transport in magnetized plasmas. Recent goals include investigating the fundamental transport physics issues and novel transport ideas/experiments and providing a means to develop new discoveries.  
      Confinement and transport research work deal with electron and ion thermal transport, particle  & impurity transport (including fast ion transport), transport physics of edge and core barriers, etc.

1.1  New transport tools for the 2006 campaign

l        ECRH with power up to 2 MW provides independent control of power deposition at different positions

l        Improved supersonic molecular beam injection (SMBI) fuelling allows deeply modulated particle transport studies

l        Improved diagnostics for zonal flow fluctuations

l        Edge density measurement by microwave reflectometer with X-mode

l        Multiple channel density measurement

1.2 Main topics are as follows

l        H-mode physics with the ECRH (2MW) and LHCD (1MW)

l        Zonal flow mechanism with GAM and near zero frequencies under the conditions IP = 100 ~ 250 kABT = 1.5 ~ 2.6TNe = 0.8 ~ 4.0 1019m -3qa = 3 ~ 6

l        Thermal transport by modulated ECRH

l        Particle transport controlled by SMBI (near liquid-nitrogen temperature) or pellet injection.

l        Impurity transport using the LBO of TiAlMo.

l        Optimization of density profile by pellet injection and MBI.

l        High density close to Greenwald limit using mixed fuelling technique by GP + PI or GP + PI + MBI

2 MHD instabilities, disruption & its mitigation

    The long-term objective of MHD stability research is to establish the basis for understanding and predicting limits to macroscopic stability of toroidal plasmas. In addition to the more focused researches, the role of the instability area is to provide a broad range of good MHD stability science, investigate instability control in regimes relevant to ITER and other burning plasmas, and explore stability physics in new regimes. Main topics include

l        Basic MHD physics

l        Tearing mode physics (including neoclassical tearing mode)

l        Sawtooth physics & sawtooth control

l        Disruption physics & disruption mitigation

l        Edge pedestal stability

l        Plasma control
Subtopics in 2006 focus on

l    MHD stabilities in low q (q < 3) discharges

l    Seed island suppression and sawteeth control by ECCD

l    ELM features in H-mode discharge

l    Control of fast current quench

l    Disruption mitigation using the MBI of argon, impurity injection by LBO

l    Database for disruption prediction

3. Radio-frequency heating & current drive

The heating and current drive area comprises experiments on the physics of electron cyclotron heating and current drive, heating and current drive at lower hybrid frequency, neutral beam heating and current drive, and bootstrap current. Recent topics are as follows.

  l        Optimization of heating and current drive for ECRF with 1~2 MW

  l        Current profile control by LHCD with 0.5 ~ 1.0 MW

  l        Synergy of ECCD & LHCD

4. Boundary and divertor physics

The boundary and divertor physics area is concerned with the plasma physics from the pedestal plasma to the interaction with the material walls at the divertor plate and main chamber walls. In the past, research was organized around Edge Transport, Pumping and Radiative Divertor, and Impurity Transport. Current topics are emphasized on

  l        Wall conditioning using siliconization or boronization

  l        Local deposition of siliconization

  l        First mirror and its property

  l        Radiative and pumped divertor

  l        Zeff and impurity controls

  l        The comparison of divertor physics results with modeling