Mode identification using “fingerprint method” on DIII-D

Comparisons between gyrokinetic simulations and experimental data from a new diagnostic tool: Faraday-effect Radial Interferometer-Polarimeter (RIP)[1] and Beam emission spectroscopy (BES)[2], are utilized for verification of micro-tearing instabilities (MTM) in DIII-D. Instability identification in simulations is achieved by using a variety of transport coefficients and their ratios to provide gyrokinetic “fingerprints”[3]. RIP will provide the $\frac{\int \delta (n_eB_r) dR}{\int n_e dR}$ with information of frequency, which can be compared with simulation results that provide strong indication that MTM are present in the pedestal region based on large $\frac{\delta B/B}{\delta n/n}$. BES measurements provide a location of density fluctuation with its amplitude at the outboard midplane. Global and local simulations using Gyrokinetic Electromagnetic Numerical Experiment (GENE) will be compared with experimental measurements. $^1$ J. Chen, W. X. Ding, D. L. Brower, et al., (2017) \url{http://dx.doi.org/10.1063/1.4960056.} $^2$ G. McKee et al., (1999) \url{https://doi.org/10.1063/1.1149416.} $^3$ M. Kotschenreuther et al., 5–6 (2019). \url{https : / /iopscience.iop.org/article/10.1088/1741-4326/ab1fa2}