Adaptive Plasma Identification from Internal and External Measurements

Abstract

A key aspect of the controlled thermonuclear fusion is the plasma identification process, that is the determination of the relevant plasma parameters from measurements taken during the fusion event. One of the classical approaches to plasma identification is based on a representation of the plasma current in terms of simpler, equivalent, currents, whose values are determined by best fitting different sets of measurements. The possibility of combining different diagnostic systems is here analyzed to assess possible improvements of the identification process: in particoular, the integration of diagnostics providing information about magnetic field both in external and internal plasma region improves the quality of the reconstruction process and gives information about the inner plasma current profile. Under suitable hypotheses, the resulting inverse problem can be formulated as the pseudoinversion of a matrix linking the unknown equivalent currents to the various measurements.