Review of the NPA Diagnostic Application at Globus-M/M2

Abstract

The application of a neutral particle analyzer (NPA) diagnostic at the Globus-M/M2 spherical tokamaks is discussed. Physical principles of the diagnostic are reviewed. Two general approaches—active and passive measurements—are described. Examples of NPA application for the ion temperature and isotope composition measurements are presented. NPA-aided studies of the energetic ions in the MHD-free discharges, as well as in the experiments with sawtooth oscillations and toroidal Alfvén eigenmodes, are considered.

Keywords

• neutral particle analyzer
• NPA
• CX diagnostics
• spherical tokamak
• ion temperature
• isotopic composition