Soft x-ray virtual diagnostics for tokamak simulations.

Area of Science:

• Plasma physics
• Fusion energy research
• Computational modeling

Background:

• Soft x-ray diagnostics are crucial for understanding plasma behavior in fusion devices like DIII-D.
• Accurate comparison between theoretical models and experimental data is essential for validating diagnostic tools and plasma simulations.

Purpose of the Study:

• To develop and validate a numerical toolset, the FAR-TECH Virtual Diagnostic Utility, for generating virtual soft x-ray data.
• To compare virtual soft x-ray signals with experimental data from DIII-D discharges.
• To assess the utility of virtual diagnostics for routine experimental data comparison and motivate further model improvements.

Main Methods:

• The FAR-TECH Virtual Diagnostic Utility was employed to generate virtual soft x-ray signals based on theoretical models.
• Plasma density and temperature profiles from experimental Thomson scattering and electron cyclotron emission data were used for modeling.
• Virtual diagnostics were compared against experimental soft x-ray data for both equilibrium and ideal linear instability scenarios.

Main Results:

• Virtual soft x-ray diagnostics showed good agreement with experimental data for plasma equilibrium.
• Virtual diagnostics based on ideal linear instability models also demonstrated reasonable agreement with experimental findings.
• The validated methodology supports the routine use of virtual diagnostics for comparing experimental data.

Conclusions:

• The developed virtual diagnostic toolset is effective for validating soft x-ray diagnostics on DIII-D.
• The good agreement justifies the methodology for routine use and encourages further simulations incorporating advanced physical models.
• Future work will explore nonideal magnetohydrodynamics and nonlinear effects using virtual diagnostics for stability modeling.