ITPA High Priority Research Tasks 2004-2005
 
 
 

These are physics R&D tasks which provide a focus for the ITPA Topical Group's activities over a timeframe of 1-2 years. They are determined on the basis of their likely importance, both in increasing understanding of fusion plasmas and in providing increased confidence in achieving significant fusion gain in ITER, as well as on the probability of achieving significant progress within this timeframe.

Diagnostics
  • Develop methods of measuring the energy and density distribution of confined and escaping alphas
  • Review requirements for measurements of neutron/a source profile and assessment of possible methods of measurement
  • Dertermine life-time of plasma facing mirrors used in optical systems
  • Develop new methods to measure steady state magnetic fields accurately in a nuclear environment and assessment of thermal EMF on irradiated coils used for steady state magnetic field measurements
  • Develop requirements for measurements of dust, and assessment of techniques for measurement of dust and erosion

MHD, Disruption and Control
  • Perform MHD stability analysis of H-mode edge transport barrier under Type I and tolerable ELM conditions.
  • Investigate/Determine island onset threshold of NTMs, stabilisation of (3,2) and (2,1) NTM islands at high b and b recovery, and possible operation with benign NTMs (FIR, seed island control); identify requirements for reactor plasmas.
  • Enhance understanding and mitigation of the effects of RWMs by analysis, experimental verification of control, determination of role of plasma rotation and error fields.  Determination of control system requirements for diagnostics.
  • Construct new disruption DB including conventional and advanced scenarios and heat loads on wall/targets.
  • Develop disruption mitigation techniques, particularly by noble gas injection.

Steady State Operation and Energetic Particles

  • Investigate hybrid scenarios for prolonged plasma operation and develop full current drive plasmas with significant bootstrap current: assess beta limits
  • Develop real time current profile control using heating and CD actuators: assess predictability, in particular for off-axis CD
  • Study fast particles collective modes in low and reversed magnetic shear configurations: Identify key parameters. Perform theory-data comparison on damping and stability, including non-linear mode dynamics and fast particle transport.

Transport Physics
  • Improve experimental characterization and understanding of critical issues for reactor relevant regimes with enhanced confinement, by:
  • Obtaining physics documentation for transport modeling  of ITER hybrid and steady-state demonstration discharges
  • Addressing reactor relevant conditions, e.g., electron heating, Te~Ti, impurities, density, edge-core   interaction, low momentum input...
  • Contribute to and utilize international experimental ITPA database for tests of the  commonality of hybrid and steady state scenario transport physics across devices
  • Encourage tests of simulation predictions via comparisons to measurements of turbulence characteristics, code-to-code comparisons and comparisons to transport scalings

Confinement Database and Modelling
  • Assemble and manage multi-machine databases, analysis tools, and physics models
  • Evaluate global and local models for plasma confinement by testing against the databases.
  • Predict the performance of Burning Plasma Experiments using the models, and  include an estimate of the uncertainty of the predictions.

Pedestal and Edge

  • Construct a Profile DB based on Inter machine experiment and perform tests of modeling using the profile DB as TG work.
  • Improve predictive capability of pedestal structure through profile modelling.
  • Construct physics-based and empirical scaling of pedestal parameters
  • Improve predictive capability for ELM size and frequency and assess accessibility to regimes with small or no ELMs.

Divertor and SOL
  • Understand the effect of ELMs/disruptions on divertor and first wall structures.
  • Improve understanding of Tritium retention & the processes that determine it.
  • Improve understanding of SOL plasma interaction with the main chamber.
  • Develop improved prescription of SOL perpendicular transport coefficients and boundary conditions for input to BPX modelling.

 
   
   
   
  Updated 3 December, 2004