Gyrokinetic Turbulence Simulation
We carry out gyrokinetic simulations of core and edge turbulence using the GEM, XGC and GENE gyrokinetic codes. The GEM code was developed at the University of Colorado. Recent focus has been on nonlinear simulations of electron and ion scale electromagnetic micro-instabilities in tokamak edge pedestal region.
(Stefan Tirkas, Haotian Chen, Yang Chen, Scott Parker)
Kinetic Core-Edge Coupling
We are part of Exascale Computing Project fusion application lead by the Princeton Plasma Physics Laboratory (PPPL). Ongoing research involves performance and optimization of the GEM gyrokinetic particle code on pre-exascale computers, including the Summit supercomputer at Oak Ridge National Laboratory which, as of this writing, is the fastest open supercomputer in the world. We have successfully coupled the core GEM code with the XGC edge code assuming adiabatic electrons and work is underway to develop a kinetic coupling allowing for kinetic electrons.
(Junyi Cheng, Haotian Chen, Yang Chen, Scott Parker)
Analysis of Gyrokinetic Edge Simulations (XGC)
Edge turbulence simulations using the XGC code developed at PPPL use enormous amounts of computer time on Summit. We are part of a paradigm shift where multiple scientists analyze heroic large-scale simulations on Summit. We are also doing companion "small tokamak" XGC simulations to further investigate scrape-off layer and blob physics.
(Junyi Cheng, Scott Parker, in collaboration with Jim Myra, Lodestar Corporation)
Quantum Algorithms for Solving the Vlasov Equation
We are developing quantum algorithms for solving hyperbolic partial differential equations widely used in plasma physics and computational fluid dynamics. We have developed a continuum algorithm solving the kinetic Landau damping problem with a complexity that scales logarithmically with the velocity grid size using Hamiltonian simulation. We are exploring generalizations including nonlinearity. It is especially challenging to obtain speedups for nonlinear equations.
(Alex Engel, Scott Parker, in collaboration with Graeme Smith, JILA)
Direct Numerical Simulation of Ultra-Cold Ion Crystals
Ultra-cold non-neutral plasma crystals made up of hundreds of ions can be used as a platform for quantum simulation and sensing experiments. Our group is using direct numerical simulation to model such systems. We include a fairly detailed model of the experimental configuration, including the rotating wall potential and Doppler cooling lasers. The simulation predicts temperatures and spectral features similar to what is observed in the NIST Penning trap experiment in Boulder, Colorado, We are exploring the stability of ultra cold crystal states and glass states.
Chen Tang, Dominic Meiser, Scott Parker, in collaboration with John Bollinger, NIST-Boulder)