"Parametric Decay Instability and Dissipation of Low-frequency Alfvén Waves in Low-beta Turbulent Plasmas," by Xiangrong "Sean" Fu (New Mexico Consortium, Los Alamos)

Date: 
Wednesday, February 21, 2018 - 2:00pm to 3:00pm
Series: 
Plasma Seminars

Plasma Seminar

Physics & Astronomy Building (PAB) Room 4-330
Wednesday, February 21, 2018
2:00 PM

Guest Speaker: Xiangrong "Sean" Fu (New Mexico Consortium, Los Alamos)

Talk Title: "Parametric Decay Instability and Dissipation of Low-frequency Alfvén Waves in Low-beta Turbulent Plasmas," by Xiangrong "Sean" Fu (New Mexico Consortium)

Abstract:

Evolution of the parametric decay instability (PDI) of a circularly polarized Alfvén wave in a turbulent low-beta plasma background is investigated using 3D hybrid simulations. It is shown that the turbulence reduces the growth rate of PDI as compared to the linear theory predictions, but PDI can still exist. Interestingly, the damping rate of ion acoustic mode (as the product of PDI) is also reduced as compared to the linear Vlasov predictions. Nonetheless, significant heating of ions in the direction parallel to the background magnetic field is observed due to resonant Landau damping of the ion acoustic waves. In low-beta turbulent plasmas, PDI can provide an important channel for energy dissipation of low-frequency Alfvén waves at a scale much larger than the ion kinetic scales, different from the traditional turbulence dissipation models. arXiv:1710.04149.

Bio:

Xiangrong (Sean) Fu earned his Bachelor's degree in Geophysics and Master's degree in Space Physics from the University of Science and Technology of China, studying electron acceleration in magnetic reconnection. He received his Ph.D. in physics in 2013 from the University of Texas at Austin, focusing on turbulent transport in fusion plasmas using quasilinear theory and gyrokinetic simulations. Afterwards he went to Los Alamos National Laboratory as a postdoc in ISR-1 group and worked on wave-particle interactions in space plasmas, including instabilities associated with anisotropic electron beams, generation of banded chorus, and formation of double layers. Starting from 2016, Sean is a research scientist at the New Mexico Consortium (Los Alamos), working on generation of whistler and EMIC waves in the inner magnetosphere and parametric decay instabilities in the solar wind turbulence, using large-scale particle-in-cell and hybrid simulations.

Event Attachments: 
Location: 
PAB 4-330