Improvements to standard diagnostic preparation and data-quality monitoring in the TCV tokamak

As modern fusion experiments continue to push the boundaries of fusion science, the number, complexity, and importance of standard diagnostics have increased. Ensuring the recording of high-quality data from standard diagnostics is a task of great importance, entrusted to Ph.D. students in the TCV tokamak. Students participate in the control room team as the ‘diagnostician of the day’ or diagnosticien du jour (DdJ). This paper presents recent improvements to the DdJ software routines that prepare standard diagnostic settings, display, and automatically monitor the quality of diagnostic data. Recent updates have automated gain preparation in several standard diagnostics, which has led to reduced saturation and minimized signal-to-noise losses in the digitization process. Refactoring has also brought important runtime improvements to automatic data check routines. Lastly, new gain-preparation routines have been implemented that predict changes in plasma temperature due to changes in external electron heating power to better prepare the Thomson Scattering diagnostic, resulting in reduced saturation compared with traditional gain-preparation routines. These improvements have been led by a multi-generational task force: the DdJ-Ninjas. • The role of the ‘diagnostician of the day’ in TCV operations is presented • Deploying automatic gain-preparation routines has reduced saturation by × 4 • Gain preparation maintains the diagnostic signal-to-noise ratio after digitization • New routines prepare diagnostics based on predictions of varying plasma conditions • Routines are integrated within the TCV plant-control system and version-controlled