Contacts: Quinn Pratt, Stephen Storment

Short Description

Multi-channel Doppler back-scattering (DBS) diagnostic analysis


DBS, Flow Velocity, Turbulence, Density Fluctuations

Long Description

The OMFIT - DBS module provides an integrated approach to analyzing data from the UCLA multi-channel Doppler back-scattering (DBS) diagnostics installed on the DIII-D and MAST(U) tokamaks. Data from both DIII-D V-band systems (one at the 60-deg port, another at the 240-port) along with legacy systems (e.g. W-band, ‘DBS5’) are available for analysis. On MAST(U) we support data from both V-band and Q-band systems. Analysis is generally performed over multiple times slices (usually order ~ 10) which are 20-200 ms (typical) in length. Labor-intensive frequency-domain analysis (fitting Doppler-shifted spectral components) is possible with the DBS_SPECTROGRAM_GUI. Ray tracing (using GENRAY) is used to calculate scattering parameters. We also support 3D beam-tracing with the SCOTTY and TORBEAM codes. DBS outputs include: probed radial locations, probed wavenumbers wavenumbers, flow velocity of turbulent structures, radial electric field, omega_E.

Typical workflows

  • Fetch raw DBS data

  • (Optional) ELM filtering

  • DBS spectrum analysis and visualization
    • Doppler shift calculation

    • Spectral power calculation

  • GENRAY/SCOTTY/TORBEAM setup with EFIT geqdsk and profiles (OMFITprofile, pFiles, input.gacode, etc…)

  • Run Ray/Beam tracing with DBS launch parameters

  • Calculate derived quantities and plot

  • Plan for experiments (ray tracing angle-scans)

Supported devices

  • DIII-D

  • MAST

  • NSTX


List of contributors sorted by number of lines authored:

24763 Quinn Pratt
  658 Stephen Storment
  123 Clive Michael
   13 Will DeShazer
   11 Orso Meneghini
    2 Bhavin Patel
    1 Fusion Bot


List of usernames sorted by number of module imports: ashourvana, prattq, ernst, smithsp, hongrongjie, yuguanying, houshman, kobayashi, fernandezp, grierson, krietedm, meneghini, schmitzl