Introducing Minimum Fisher Regularisation Tomography to Bolometric and Soft X-ray Diagnostic Systems of the COMPASS Tokamak
The contribution focuses on plasma tomography via the Minimum Fisher Regularisation (MFR) algorithm applied on data from the recently commissioned tomographic diagnostics on the COMPASS tokamak. The MFR expertise is based on previous applications at Joint European Torus (JET), as exemplified in a new case study of the plasma position and Zeff analyses based on JET SXR tomographic reconstruction. Subsequent application of the MFR algorithm on COMPASS AXUV bolometric data disclosed a peaked radiating region near the limiter, and clearly allowed for a high resolution plasma positioning independent of the magnetic diagnostics. Moreover, its time evolution indicates transient plasma cooling following a radial plasma shift. In SXR data, MFR demonstrated that a proper calibration of the cameras on an X-ray source would be required.