Diagnostic Overview for Non-solenoidal Startup Experiments on Pegasus-III

The diagnostic set for initial experiments on Pegasus-III is designed to quantify the efficacy of DC helicity injection and microwave injection as approaches to non-solenoidal tokamak startup. The diagnostic set must constrain kinetic equilibrium reconstructions, quantify magnetic helicity dissipation, characterize the MHD and kinetic activity associated with current drive and magnetic relaxation, quantify impurity content and radiative losses arising from plasma-material interaction, and characterize the current drive sources. The magnetics measurements utilize cable shielding and differential balancing to suppress volt level EMI from switching power supplies driving the electromagnets. Active charge exchange spectroscopy, microwave interferometry, and a Thomson scattering system provide constraints for the kinetic profiles. Radiation measurements from an AXUV diode array, a visible bremsstrahlung system, and SPRED are used with STRAHL simulations to quantify impurity dynamics. Visible imaging and Stark broadening measurements are used to characterize the dense injector plasmas. Microwave imaging is used for optimizing the launch angle and quantifying mode conversion efficiency for electron Bernstein wave injection.