Integration of OEGDE Modelling into synthetic diagnostics for assessment of W Transport in the Scrape Off Layer of WEST

The WEST tokamak provides a unique capability to study the performance of a fully-tungsten, long pulsed plasma similar to the ITER operating scenario. Understanding tungsten (W) transport in the scrape off layer (SOL) is crucial for preventing contamination of the core plasma. To improve the understanding of SOL models, synthetic diagnosis techniques are needed to make direct comparisons with the experimental diagnostic data. A synthetic spectroscopy diagnosis technique has been developed using wavelengths and photon emissivity coefficients (PECs) for the full neutral W spectrum calculated by ColRadPy to compare with visible spectroscopy brightness (ph.m^-2.s^-1.sr^-1). The PECs are used to create emissivity profiles based on the OEDGE background plasma and W profiles. The CHERAB framework is used to simulate the expected intensities of the emission lines in the visible wavelength range by integrating the emissions over the lines of sight at the lower divertor and baffle and accounting for reflections on the all metal walls of WEST. This workflow is employed to compare the expected W excitation line of sight intensities and W-I spatial impurity profiles produced from modelling of a WEST L-mode power scan 1.5 – 2.35 MW reaching the SOL to the corresponding experimental data. The level of agreement of the synthetic spectra impurity profiles with measured spectra and impurity brightness profiles is evaluated to benchmark the workflow.



This work is supported by the U.S. DOE under Grant Number: DE-SC0020414