CQL3D-M, A 3D Nonlinear, Bounce-Averaged Collision Model Coupled with Neutrals for Magnetic Mirrors, with Fusion Applications

The CQL3D-M continuum finite-difference bounce-averaged Fokker-Planck code for modeling of magnetic mirror plasmas is an adaption and enhancement of CQL3D for tokamaks. The code is run in a fully nonlinear collisional mode giving f(u,theta,rho;t). The NL feature is new compared to usual tokamak-type modeling giving deviations from Maxwellians, and conserves particles, momentum, and energy. With neutral beams and other sources, the resulting distributions give the time-evolving balance between plasma particle/momentum/energy and the losses to the magnetic loss cone, radiation, and radial transport. Results are obtained for an illustrative DT fusion case for the BEAM[1] conceptual mirror. For a simulation with 10 MW of DT neutral beam power, 7 MW absorbed, the released fusion power is 3 MW. Further optimizations are anticipated. It can be particularly important to include the effects of neutrals in the modeling, so CQL3D-M is being coupled to the FIDASIM Monte Carlo neutrals code[2]. The overall aim of the numerical project is to kinetically model all the particles in the device, both ionized and neutral species.

[1] C.B. Forest et al., JPP 90, 975900101 (2024). [2] J. Caneses-Marin, this meeting.

Supported by: USDOE grants DE-FG02-04ER54744, DE-SC0024369, DE-SC0024887 and Realta Fusion.