This issue highlights some of CASC’s contributions to making controlled laboratory fusion possible at the National Ignition Facility.

# Topic: *Transport*

Open-source software has played a key role in paving the way for LLNL's ignition breakthrough, and will continue to help push the field forward.

For the physicists, computer scientists, and code developers who have worked on fusion for decades, computer simulations have been inexorably tied to the National Ignition Facility’s quest for ignition.

A high-fidelity, specialized code solves partial differential equations for plasma simulations.

Highlights include power grid challenges, performance analysis, complex boundary conditions, and a novel multiscale modeling approach.

Highlights include scalable deep learning, high-order finite elements, data race detection, and reduced order models.

Proxy apps serve as specific targets for testing and simulation without the time, effort, and expertise that porting or changing most production codes would require.

The SAMRAI library is the code base in CASC for exploring application, numerical, parallel computing, and software issues associated with structured adaptive mesh refinement.

High-resolution finite volume methods are being developed for solving problems in complex phase space geometries, motivated by kinetic models of fusion plasmas.

Researchers are testing and enhancing a neutral particle transport code and its algorithm to ensure that they successfully scale to larger and more complex computing systems.