Speaker
Description
In this talk, GUERNICA, a new continuum kinetic neutral code, is presented for the simulation of atomic hydrogen transport in fusion edge plasmas, solving the Boltzmann equation with charge exchange, ionization and elastic neutral-neutral collisions. Neutral atoms strongly influence tokamak edge and divertor physics through fueling, momentum exchange and volumetric power loss [1]. Accurate neutral modeling is increasingly important for future devices, particularly for detachment which is central to managing power exhaust [2]. In contrast to Monte Carlo approaches, which suffer from noise and high computational cost in strongly collisional regimes, GUERNICA combines a discontinuous Galerkin discretization in configuration space with a discrete velocity formulation, enabling noise-free, high-fidelity solutions whose cost is independent of plasma-neutral collisionality. Verification and validation are demonstrated using analytic test problems and comparisons against DEGAS2 in one-dimensional configurations. Performance results show favorable scaling with velocity resolution and high throughput on single-GPU hardware. These results are extended to initial two-dimensional simulations in a MAST-U geometry driven by a static plasma background, underscoring the potential of deterministic kinetic neutral modeling for next-generation edge studies.
[1] S. Mordijck, Nucl. Fusion 60, 082006 (2020)
[2] U. Fantz et al, J. Nucl. Mater. 290–293, 367–73 (2001)
Work supported by US DOE under DE-SC0007880.