Physics

Dr Kiritkumar Makwana
IIT Hyderabad

Abstract: Plasma turbulence is a phenomenon characterized by energy transfer over a vast range of spatial-temporal scales, for ex. in the solar wind. Magnetic reconnection is a process that involves conversion of magnetic energy into particle energy via change in magnetic topology, for ex. in solar flares. Both these phenomena are ubiquitous and interlinked in a variety of space, astrophysical, & laboratory plasmas. I will briefly introduce some past research and some major open questions in these topics. To tackle these questions, fluid models are used to simulate a plasma at large scales while particle-in-cell models are used at small scales where the particulate nature of plasma (“kinetic” physics) becomes important. I will describe my work which has involved using, comparing, and coupling simulations of these different models. This has led to the discovery of novel features of plasma turbulence in the compressively-driven fluid regime as well as dissipative structures in the kinetic regime. These features have also been seen in observations. In magnetic reconnection we find that kinetic physics plays an important role even at large scales. I will also describe exciting opportunities and challenges that lie ahead in this field, especially with new computational tools and observational data.