My scientific interests are, I think, pretty broad. I was almost exclusively interested in astronomy and astrophysics when I entered college, but I slowly developed a taste for other areas of physics. I am active in several different fields of energy modeling and simulation as well as quantum computing and information, kinetic theory and data mining.
I am the lead architect, developer and principal investigator of the NEAMS Integrated Computational Environment (NiCE) for the US Department of Energy's Advanced Modeling and Simulation Office in the Office of Nuclear Energy. The primary goal of NiCE is to create a unified, integrated and dynamically reconfigurable environment in which analysts and developers can perform modeling and simulation tasks without having to fight with command line tools or hacked-together utilities. This project has many research challenges, the most important of which is the development of a single "workflow engine" that easily handle all sorts of different tasks - from problem setup to data analysis - for many different fields.
In addition to the development of new modeling and simulation capabilities, NiCE is directly responsible for a new branch of my research program in the area of nuclear simulation data mining. After working with simple post-processing tools for nuclear simulation results, my team and I worked to apply data mining and anomaly detection techniques to nuclear data in a scalable way. This is an exciting development with some success (two papers, some talks) and I’m looking forward to its development in the future.
I learned about quantum computing and information as an undergraduate and had the opportunity to work in the field a couple of years ago with some colleagues at the Lab. My team and I worked with those colleagues to develop a simulator for adiabatic quantum computers and we are currently researching ways that they simulator can be used to simulate these systems for large numbers of cubits. (>40 cubits is large for a simulation and some systems available commercially have 512 cubits.)
My newest project is the Xolotl Plasma-Surface Interactions simulator that is under development for the U.S. Department of Energy’s Scientific Computing through Advanced Computing program. This project is developing a brand new high-performance computing simulator for investigating the interfaces between plasmas and surfaces in tokamaks and linear fusion devices to determine the damage due to Helium irradiation of the bulk. In addition to the computational physics research, my team and I are also investing a large amount of effort into determining the best ways to embed performance monitoring and visualization technologies into the software. We are also doing research to determine the best techniques for quantifying the uncertainty in Xolotl’s results so that it can be compared directly to experiment.
I am still active in astrophysics when I have time to spare from all of these other activities. I no longer research colliding galaxies, but I do continue to work with the joint UTK+ORNL astrophysics group to investigate novel methods for solving reaction networks (“kinetic theory”). Over the past decade or so we have developed and published on several new algorithms that allow extremely stiff systems of equations to be integrated explicitly by exploiting the underlying physics and making appropriate approximations.
As a perennially curious man, I am always adding new things to my plate and looking for opportunities to collaborate to answer meaningful and exciting questions.