Simulation: The Digital Laboratory


Plasma physics simulation

The ultimate success of any physical theory lies in its predictive power. It is exceedingly complex to find analytical solutions to the equations that govern laser plasma interactions in HEDP as the extreme conditions that exist under an ultra-intense laser focus span 5 orders of magnitude in density and intensity. The problem is made no easier by the fact that these quantities change on very small temporal and spatial scales. Additionally, the transport of large, relativistic currents must take into account self-generated fields and the material response to these currents. On top of all this, the scales of the particles themselves that come into play are enormous, with the number of particles in the systems we examine being on the order of Avogadro's number (1023) for solid materials!

At the end of the day, keeping track of such large numbers of particles involves making approximations by using distributions, and by using smaller numbers of macroscopic particles to represent the real system. These systems may approach several hundred million (108) particles or more. Though greatly reduced, this is still a large number of particles, and it is a monumental feat to keep track of all of them, let alone their interactions with electromagnetic fields present in the system.

Modeling such exotic systems requires the use of immense supercomputing power granted by advanced parallel processors. Splitting the work up over multiple processors facilitates the required calculations and puts valid physical simulations within reach. Fortunately, Ohio State is in a strong position to model these types of systems by utilizing the computing resources available at the Ohio Supercomputer Center (OSC). With these techniques, physics calculations become tractable, and our simulations can be used to validate experimental models, and perhaps guide the design of future experiments.

The list below offers a sample of the topics currently under study.