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Revathi Jambunathan

Contact Information Revathi Jambunathan MS 50A-3111 Lawrence Berkeley National Lab 1 Cyclotron Rd. Berkeley, CA 94720 510-486-6900 (fax) [email protected]

I am a Research Scientist in the Center for Computational Sciences and Engineering (CCSE) in the Computing Sciences Area at the Lawrence Berkeley National Laboratory. I am interested in studying the interaction of charged particles in the presence of electromagnetic fields and how their behavior at the kinetic or micro-scale affects the dynamics of plasma systems over large spatial and temporal scales. Understanding these multi-scale interactions are crucial to the development of efficient plasma-based linear acceleratiors that has numerous applications in medicine, industry and the energy sectors. The well-established Particle-In-Cell method serves as a computational lens to study the evolution of and interaction between the charged particles and the self-consistent electric and magnetic fields. The most important challenge in simulating the above mentioned systems using fully-kinetic PIC methods is their computational cost. Yes! This research requires high-performance computing to exploit the computational acceleration provided by heterogeneous computer architectures on leadership-class supercomputers.

Here at CCSE, I contribute to the development and optimization of WarpX, which is an advanced three-dimensional electromagnetic Particle-In-Cell code that is primarily used to study laser-plasma interactions to build effective plasma-based linear particle accelerators. To efficiently resolve the dense plasma regions, we use the AMReX framework which handles the adaptive mesh generation, domain decomposition, and also data-transfer across the heterogeneous computer architectures. Recently, we have started extending WarpX to also simulate particle acceleration in astrophysical processes, such as, pulsar magnetospheres and magnetic reconnection. The fact that AMReX and WarpX are open-source codes that will benefit a broader plasma community make this work even more satisfying. My work has the potential to markedly reduce the development times spent by researchers in re-inventing their own frameworks. Instead, now the focus will be on reaching for the stars or at-least modeling them! :)

• R. Jambunathan, H. Jones, L. Corrales, H. Klion, M. Rowan, A. Myers, W. Zhang, and J.-L. Vay Application of mesh refinement to relativistic magnetic reconnection Submitted to Physics of Plasmas , August 2024 [arxiv]
• P. Kumar, A. Nonaka, R. Jambunathan, G. Pahwa, S. Salahuddin, and Z. Yao, FerroX: A GPU-accelerated, 3D Phase-Field Simulation Framework for Modeling Ferroelectric Devices, Computer Physics Communications, 108757, 2023 [arxiv] [doi]
• R. Jambunathan, Z. Yao, R. Lombardini, A. Rodriguez, and A. Nonaka, Two-Fluid Physical Modeling of Superconducting Resonators in the ARTEMIS Framework, Computer Physics Communications, 291, 2023. [arxiv] [doi
• H. Klion, R. Jambunathan, M. E. Rowan, E. Yang, D. Willcox, J.-L. Vay, R. Lehe, A. Myers, A. Huebl, W. Zhang, Particle-in-Cell Simulations of Relativistic Magnetic Reconnection with Advanced Maxwell Solver Algorithms, The Astrophysical Journal, 925, 1, 2023. [arxiv] [doi
• S. Sawant, Z. Yao, R. Jambunathan, and A. Nonaka, Characterization of Transmission Lines in Microelectronics Circuits using the ARTEMIS Solver, IEEE J. on Multiscale and Multiphysics Comp. Tech., 8, 2022. [doi
• R. Lehe, A Bielly, L. Giacomel, R. Jambunathan, J.L. Vay, "Absorption of charged particles in perfectly matched layers by optimal damping of the deposited current", Physical Review E, Oct 2022 [arxiv] [doi
• Z. Yao, R. Jambunathan, Y. Zeng, and A. Nonaka, A Massively Parallel Time-Domain Coupled Electrodynamics-Micromagnetics Solver, International Journal of High Performance Computing Applications, 10943420211057906, 2021. [link] [arxiv]
• R. Jambunathan, and D. Levin, "Kinetic, three-dimensional, PIC-DSMC simulations of ion thruster plumes and the backflow region", IEEE Transactions on Plasma Science, 2020 [doi]
• R. Jambunathan, and D. Levin, "A self-consistent open boundary condition for fully-kinetic plasma thruster simulations", IEEE Transactions on Plasma Science, 2020 [doi]
• R. Jambunathan, D. Levin, A. Borner, JC. Ferguson, and F. Panerai, "Prediction of gas transport properties through fibrous carbon preform microstructures using direct simulaiton Monte Carlo", International Journal of Heat and Mass Transfer, 2019. [doi]
• R. Jambunathan and D. Levin, "CHAOS: An octree-based PIC-DSMC code for modeling of electron kinetic properties in a plasma plume using MPI-CUDA parallelization", Journal of Computational Physics, 2018. [doi]
• R. Jambunathan and D. Levin, "Advanced parallelization strategies using hybrid MPI-CUDA octree DSMC method for modeling flow through porous media", Computers & Fluids, 2017. [doi]
• R. Jambunathan and D. Levin, "Grid-free octree approach for modeling heat transfer to complex geometries", Journal of Thermophysics and Heat Transfer, 2016. [doi]

• Comparison of plasma plume characteristics obtained using PIc-DSMC approach with Boltzmann approximations, International Conference On PLasma Science, (ICOPS) , Denver, Colorado, June-2018.
• A new self-consistent boundary condition for modeling of plasma plume evolution using a fully-kinetic PIC approach, International Conference On PLasma Science, (ICOPS) , Denver, Colorado, June-2018.
• Multi-GPU PIC solver for modeling of ion thruster plasma plumes, AIAA Scitech Conference , Kissimmee, Florida, January-2018.
• Prediction of thermal proctection system material permeaiblity and hydraulic tortuosity factor using DSMC, AIAA Scitech Conference , Kissimmee, Florida, January-2018.
• Kinetic modeling of plasma plumes using multi-GPU forest-of-octree approach, 35th International Electric Propulsion Conference , Atlanta, Georgia, October 2017.
• Characterization of thermal protection system materials using CHAOS DSMC solver, 9th Ablation Worshop, Bozemann, Montana, August 2017.
• Forest of octree DSMC simulation of flow through porous media, 30th International Symposium on Rarefied Gas Dynamics, August 2016.
• A hybrid CPU-GPU Parallel octree-based Direct Simulation Monte Carlo Approach, Joint Thermophysics and Heat Transfer Conference, Dallas, Texas, June 2015.
• Gridless DSMC approach for analysis of fractal-like spherical aggregates, Joint Thermophysics and Heat Transfer Conference, Atlanta, Georgia, June 2014.

• WarpX: Toward exascale modeling of pulsar magnetospheres, Connecting Micro and Macro Scales in Astrophysical Plasmas , Kavli Institute of Theoretical Physics, Santa Barbara.
• Ion thruster plasma plume simulations using CHAOC PIC-DSMC, SIAM CSE-2019 , Spokane, Washington, February 2019.