As part of the Plasma Physics group and John Adams Institute for Accelerator Science, I study a variety of fundamental and applied aspects of non-linear and relativistic energy-density propagating structures excited in various types of plasmas. This quest lies at the confluence of distinctly identified research areas such as advanced accelerator physics, non-linear plasma physics, computational electromagnetics & electrodynamics, high-energy density physics etc.
These unusual plasma density structures that are excited by increasingly high-intensity energy-sources sustain spatial charge-separation between the plasma particles with differing inertia. As the intensity (energy density) of the driving energy-sources increases, density structures and interaction processes tend towards unfamiliar and exotic regimes. Matter under such extreme conditions are usually found in astrophysical objects.
Plasma-based acceleration methods that use the extraordinary electromagnetic fields of such structures, hold the promise for developing low-cost, compact and tunable sources of high-energy particle beams and pulses of light. This has the potential to transform several fields of scientific research that rely on light & particle sources for visualizing or manipulating physical, biological & chemical processes.
In my work, I analytically model the interaction of energy sources of high energy density (intense beams of photons or particles) with a variety of plasmas. This leads to estimates of properties of the mechanisms & processes excited by these interactions.
As these interactions invariably excite non-linear phenomena in the plasma, computational modeling is often a more accurate way to investigate the dynamics of interaction and evolution. The interaction space typically contains around a trillion particles whose dynamics evolves in time, requiring cutting-edge numerical methods & approximations for accurate modeling. Such theoretical explorations eventually lead to predictions of measurable signatures or scaling laws that could be obtained in a well-designed experiment.
My research interests span topics in applied electromagnetics, computational physics, plasma physics, accelerator physics, intense laser-plasma and beam-plasma interactions, nonlinear dynamics and laser diodes.
Imperial 2nd Yr. B.Sc. Physics Academic Tutorials - 2016-17
Unifying Laser, Plasma & Accelerator Physics, USPAS, June 2016 with Prof. Seryi
Imperial 3rd Yr. B.Sc. Physics Academic Tutorials (Comp. Exam) - 2015-16
Electronics Design Lab, Duke University, Fall 2014
Laser Plasma Accelerators (with E.Esarey & C.Shroeder), USPAS, Jan 2013
Electromagnetics, Duke University, Fall 2011
et al., 2014, Improving the self-guiding of an ultraintense laser by tailoring its longitudinal profile., Phys Rev Lett, Vol:113
et al., 2013, Relativistically induced transparency acceleration of light ions by an ultrashort laser pulse interacting with a heavy-ion-plasma density gradient., Phys Rev E Stat Nonlin Soft Matter Phys, Vol:88
Sahai AA, 2014, Motion of the plasma critical layer during relativistic-electron laser interaction with immobile and comoving ion plasma for ion accelerationa), Physics of Plasmas, Vol:21, ISSN:1070-664X, Pages:056707-056707
Sahai AA, Katsouleas TC, Optimal positron-beam excited plasma wakefields in Hollow and Ion-Wake channels
Sahai AA, Katsouleas TC, Longitudinal instabilities affecting the moving critical layer laser-plasma ion accelerators, Advanced Accelerator Workshop 2014