Abhay K. Ram

Biography

Education

University of Nairobi, Kenya, B.S., Mathematics (1971)
Massachusetts Institute of Technology, Ph.D., Physics (1977)

Expertise

Theoretical: electromagnetic wave propagation; wave scattering; nonlinear dynamics; wave-particle interactions in plasmas.

Research

Magnetic Fusion: Heating, current drive, and transport induced by radio frequency waves (ion cyclotron, lower hybrid, and electron cyclotron) in toroidal fusion devices. Scattering of radio frequency waves by plasma fluctuations. Propagation and damping of electromagnetic waves in plasmas. Parametric wave processes in the plasma edge.

Inertial Confinement Fusion: Laser-plasma interactions, nonlinear evolution of plasma waves, wave-particle interactions.

Space and Astrophysical Plasmas: Diffusion of magnetic field lines and charged particles in three-dimensional force-free magnetic fields, transport of particles in chaotic magnetic fields, nonlinear acceleration of ionospheric ions by waves, and propagation of waves in density cavities.

Nonlinear Plasma Physics: Coherent and chaotic dynamics of charged particles induced by electromagnetic waves, characterization of particle diffusion and the evolution of particle distribution function.

Publications

A. D. Papadopoulos, E. N. Glytsis, A. K. Ram, and K. Hizanidis, “Scattering of radio frequency waves by randomly modulated density interfaces in the edge of fusion plasmas,” accepted for publication in Journal of Plasma Physics (2021).

G. Vahala, L. Vahala, M. Soe, and A. K. Ram, “One- and two-dimensional quantum lattice algorithms for Maxwell equations in inhomogeneous scalar dielectric media I: theory,” Radiation Effects and Defects in Solids 176:1-2, 49-63 (2021).

G. Vahala, M. Soe, L. Vahala, and A. K. Ram, “One- and two-dimensional quantum lattice algorithms for Maxwell equations in inhomogeneous scalar dielectric media. II: simulations,” Radiation Effects and Defects in Solids 176:1-2, 64-72 (2021).

A. K. Ram, K. Hizanidis, F. Bairaktaris, A. Papadopoulos, and S.-I. Valvis (2020) “Scattering of radio frequency waves by density filaments,” Radiation Effects and Defects in Solids 175:11-12, 976-980 (2020).

G. Vahala, L. Vahala, M. Soe, and A. K. Ram (2020) “Building a three-dimensional quantum lattice algorithm for Maxwell equations,” Radiation Effects and Defects in Solids 175:11-12, 986-990 (2020).

G. Vahala, L. Vahala, M. Soe, and A. K. Ram, “Unitary Quantum Lattice Simulations for Maxwell Equations in Vacuum and in Dielectric Media,” Journal of Plasma Physics 86, 905860518 (2020).

A. D. Papadopoulos, E. N. Glytsis, A. K. Ram, S. I. Valvis, P. Papagiannis, K. Hizanidis, and A. Zisis, “Diffraction of radio frequency waves by spatially modulated interfaces in the plasma edge in tokamaks,” Journal of Plasma Physics 85, 905850309 (2019).

L. Vahala, G. Vahala, M. Soe, A. K. Ram, and J. Yepez, “Unitary qubit lattice algorithm for three-dimensional vortex solitons in hyperbolic self-defocusing media,” Communications in Nonlinear Science and Numerical Simulations 75, 152 (2019).

N. A. Lopez and A. K. Ram, “Mode-conversion of the extraordinary wave at the upper hybrid resonance in the presence of small-amplitude density fluctuations,” Plasma Physics and Controlled Fusion 60, 125012 (2018).

S. I. Valvis, A. K. Ram, K. Hizanidis, P. Papagiannis, A. Papadopoulos, A. Zisis, I. G. Tigelis, E. Glytsis, “Scattering of radio frequency waves by cylindrical filaments with general orientation relative to the magnetic field,” Journal of Plasma Physics 84, 745840604 (2018).

F. Bairaktaris, K. Hizanidis, A. K. Ram, P. Papagiannis, C. Tsironis, Y. Kominis, E. Glytsis, O. Chellai, S. Alberti, I. Furno, “Homogenization theory for the effective permittivity of a turbulent tokamak plasma in the scrape-off layer,” Journal of Plasma Physics 84, 45840501 (2018).

S. Samanta, M. S. Janaki, A. K. Ram, and B. Dasgupta, “Characterization of magnetic field lines in connection with their transport in Beltrami magnetic fields,” Physics of Plasmas 25, 122308 (2018).

Z. C. Ioannidis, A. K. Ram, K. Hizanidis, and I. Tigelis, “Computational studies on scattering of radio frequency waves by density filaments in fusion plasmas.” Physics of Plasmas 24, 102115 (2017).

A. K. Ram and K. Hizanidis, “Scattering of radio frequency waves by cylindrical density filaments in tokamak plasmas,” Physics of Plasmas 23, 022504 (2016).

A. K. Ram, B. Dasgupta, V. Krishnamurthy, and D. Mitra, “Anomalous diffusion of field lines and charged particles in Arnold-Beltrami-Childress force-free magnetic fields,” Physics of Plasmas 21, 072309 (2014).
https://doi.org/10.1063/1.4890360

D. Mitra, A. Brandenburg, B. Dasgupta, E. Niklasson, and A. K. Ram, “Particle energization through time-periodic helical magnetic fields,” Physical Review E 89, 042919 (2014).

Abhay K. Ram, Brahmananda Dasgupta, V. Krishnamurthy, and Dhrubaditya Mitra, “Anomalous diffusion of field lines and charged particles in Arnold-Beltrami-Childress force-free magnetic fields,” Physics of Plasmas 21, 072309 (2014).

Dhrubaditya Mitra, Axel Brandenburg, Brahmananda Dasgupta, Eyvind Niklasson, and Abhay Ram, “Particle energization through time-periodic helical magnetic fields,” Physical Review E 89, 042919 (2014).

A. K. Ram and K. Hizanidis, “Scattering of electromagnetic waves by a plasma sphere embedded in a magnetized plasma,” Radiation Effects and Defects in Solids 168, 759 (2013).

A. K. Ram, K. Hizanidis, and Y. Kominis, “Scattering of radio frequency waves by blobs in tokamak plasmas,” Physics of Plasmas 20, 056110 (2013).

P. A. Zestanakis, Y. Kominis, K. Hizanidis, and A. K. Ram, “Heating of ions by high frequency electromagnetic waves in magnetized plasmas,”  Physics of Plasmas 20, 072507 (2013).

Abhay K. Ram and Kyriakos Hizanidis, “Scattering of electromagnetic waves by a plasma sphere embedded in a magnetized plasma,” Radiation Effects and Defects in Solids: Incorporating Plasma Science and Plasma Technology 168, 759 (2013).

P. A. Zestanakis, Y. Kominis, K. Hizanidis, and A. K. Ram, “Heating of ions by high frequency electromagnetic waves in magnetized plasmas,” Physics of Plasmas 20, 072507 (2013).

Abhay K. Ram and Brahmananda Dasgupta, “Dynamics of charged particles in spatially chaotic magnetic fields,” Physics of Plasmas 17, 122104 (2010).

Y. Kominis, A. K. Ram, and K. Hizanidis, “Kinetic Theory for Distribution Functions of Wave-Particle Interactions in Plasmas,” Physical Review Letters 104, 235001 (2010).

Teaching

Introduction to Plasma Physics – 22.611J (Fall 2012)

Talks & Media

“Scattering of radio frequency waves by plasma blobs,” Magneto-fluid Dynamics Seminar, New York University, New York (November 18, 2014).

“Scattering of ECRF waves by edge density fluctuations and blobs,” 18th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating, Nara, Japan (April 22, 2014).

“Scattering of waves by blobs in tokamak plasmas: venturing beyond geometric optics,” invited talk 54th Annual Meeting of the APS Division of Plasma Physics, Providence, Rhode Island (October 30, 2012).

“Scattering of ECRF waves by edge density blobs and fluctuations in tokamak plasmas,” 17th Joint Workshop on Electron Cyclotron Emission and Electron Cyclotron Resonance Heating, Deurne, Netherlands (May 7, 2012).

“Dancing with the Stars – Fusion Energy”, seminar at the Knight Science Journalism at MIT (April 1, 2010).