# Computational Physics Group

The Computational Physics Group carries out research and development in collaboration with all of LLNL. Emphasis is placed on the use of modern numerical and computational techniques to solve problems. Examples include the use of CASC developed linear and non-linear solvers in Laboratory programmatic codes used to solve radiation transport, fluid dynamics, various types of particle transport, and multi physics systems. Group members contribute to efforts in defense technology, laser target simulations, materials science, astrophysics, engineering design, computational performance, and others.

Computational Physics Group members deal with an extremely broad variety of problems. The bottom line for us is to solve scientific problems by combining understanding of physical systems with good code design, appropriate algorithms, and efficient implementations, typically on parallel computers. Our research is usually motivated by consideration of issues that arise from real-world situations. Our group members collaborate on physics-based projects with scientists from organizations around the Laboratory, as well as on multi-institution projects with universities and other labs.

## Group Lead

Louis Howell: radiation transport, radiation diffusion, computational fluid dynamics, adaptive mesh refinement

## Research Staff

Bill Bateson: strongly driven systems, deterministic and non-deterministic transport, scientific algorithms, software tools methods

Peter Brown: linear and nonlinear systems, neutral particle transport

Britton Chang: neutron and photon transport, nonlinear methods, multigrid methods

Xiao Chen: uncertainty quantification, machine learning, nonlinear model reduction, data assimilation

Aaron Fisher: software development, parallel algorithms, nonlinear electromagnetics, solid mechanics

Mike Lambert: parallel algorithms, linear solvers, Z-pinch simulation, deterministic and non-deterministic transport, strongly driven system simulation

Nathan Masters: computational physics, interface reconstruction, adaptive mesh refinement, rarefied gas dynamics

Jose Milovich: laser target simulations, hydrodynamic instabilities, performance tuning, parallel algorithms

Doug Peters: fluid dynamics, transport modeling, software calibration and validation

Dan Shumaker: plasma physics, geologic modeling, scientific algorithms, simulation performance

Charles Tong: uncertainty quantification

Ping Wang: parallel algorithms and performance, computational physics,adaptive mesh refinement, radiation and hydrodynamics modeling