Orbit-Space Integrated Data Analysis of Fast Ions in the C-2W Field Reversed Configuration

The C-2W advanced beam-driven field reversed configuration (FRC) device utilizes 15-40 keV neutral beams to create a large population of fast ions, which are critically important for FRC heating, current drive, and stabilization. [1, 2] The suite of fast ion diagnostics on the C-2W device include neutral particle analyzers (NPAs), scintillating neutron detectors, silicon proton detectors, and particle bolometers. Fast and accurate diagnostic modeling techniques are vital to developing an understanding of these fast ion diagnostic signals, and how they relate to fast ion dynamics. We present an integrated data analysis (IDA) paradigm which utilizes weight functions to model these signals. Fast ion orbits in high-beta FRCs are well described by two conserved variables, which allows for the development of two-dimensional “orbit-space” weight functions which fully represent the diagnostic sensitivity, instead of the full four or six dimensions required by many traditional methods. Combined with Monte Carlo particle simulations, they provide a powerful tool for rapid modeling of fast ion diagnostics in an integrated framework with other diagnostic information. We also utilize this newly-developed IDA model to infer properties of the fast ion distribution and explore fast ion dynamics, utilizing both forward simulations and experimental data.

 

[1] H. Gota et al., Nucl. Fusion 59, 112009 (2019).

[2] M. Binderbauer et al., Phys. Plasmas 22, 056110 (2015).