The new plasma diagnostic MANTIS developed by DIFFER is giving a detailed look at the plasma conditions in the Swiss fusion experiment TCV. With 10 different channels and a frame rate of 200-2000 images per second, MANTIS can analyse density, temperature and the presence of impurities in the intense exhaust plasma of TCV. With its real-time data analysis capability, MANTIS is designed to hook into the reactor control system and steer the plasma to optimal conditions.
The MANTIS system was developed by post-doc dr. Wouter Vijvers on an NWO Veni personal grant. At TCV (Swiss Plasma Center at EPFL Lausanne), his diagnostic is one of the systems that monitors the discharges in this fusion experiment. MANTIS looks at the lower part of the plasma discharge, where the hot, charged gas is guided to the reactor exhaust wall by magnetic fields. TCV is designed especially to shape this exhaust plasma into different geometries and study optimal ways of exhausting heat and particles from fusion reactors.
Real-time analysis at many wavelengths
The MANTIS system collects light through a single window in the tokamak and feeds it to ten cameras that each look at a very narrow wavelength band. The system is uniquely detailed and fast, says Wouter Vijvers. Combining the information from these cameras allows the system to pinpoint the exact position of the plasma edge and reconstruct temperatures along the exhaust stream, but also to analyse where impurities are present and how they influence the plasma conditions.
The MANTIS multispectral and real-time capabilities make it an interesting tool for researchers; several research groups at TCV are already using data from MANTIS, and other European fusion experiments have expressed an interest in a MANTIS-system of their own.