Physics

Feiyu Li, NMC Research Scientist
Sean Fu, NMC Research Scientist
Seth Dorfman, SSI Research Scientist

Supported by NASA and DOE grants commencing 2023, the team will aim for the first observation of Alfven wave parametric decay in the laboratory. Alfven waves are a major carrier of energy over long distances in space plasma. The dissipation of Alfven wave energy through nonlinear interactions may be powerful enough to accelerate the solar wind — a stream of plasma particles ejected from the Sun. The Alfven wave parametric decay instability (PDI) — where a large amplitude Alfven wave decays into a daughter Alfven wave and a sound wave — is widely conceived to be a key energy dissipation mechanism, driving plasma heating and turbulence. Yet, observational evidence of PDI in space is not well established due to complex space environments and limited spacecraft explorations.

These projects will take advantage of the Large Plasma Device (LAPD) at UCLA — 20-meter long linear device, and conduct PDI studies under well controlled conditions. In the past two years, the team have developed 3D kinetic simulations that are tailored to model LAPD Alfven wave studies using realistic geometries and wave and plasma conditions. These capabilities will enable detailed characterization and prediction of LAPD conditions needed to drive PDI. The projects will also devise novel methods to measure the growth rates of the instability and perform detailed scaling studies of PDI versus the broad LAPD parameters. The study will aid our understanding of the role of PDI in the solar terrestrial plasma system and help benchmark existing theories and our computational models.

Igor Savukov, LANL Staff Scientist, NMC Affiliate
Bryan Travis, NMC Research Scientist
John George, NMC Research Scientist
Olga Korzh, Junior Research Scientist

The goal of this research is to conduct nuclear-spin optical rotation (NSOR) experiments at Texas A&M university in collaboration with the Dr. Christian Hilty at his dynamic nuclear polarization (DNP) facility. NSOR can be of interest to applications related to National Security and it is imperative that basic science be investigated in order to evaluate the potential for National Security applications.

Igor Savukov, LANL Staff Scientist, NMC Affiliate
John George, NMC Research Scientist
Olga Korzh, Junior Research Scientist

The goal of this research is to conduct nuclear-spin optical rotation (NSOR) experiments at Texas A&M university in collaboration with the Dr. Christian Hilty at his dynamic nuclear polarization (DNP) facility. NSOR can be of interest to applications related to National Security and it is imperative that basic science be investigated in order to evaluate the potential for National Security applications.

Fan Guo, LANL Staff Scientist, NMC Affiliate

Magnetic reconnection is a fundamental plasma process that allows rapid changes of magnetic field topology and the conversion of magnetic energy into plasma kinetic energy. It has been extensively discussed in solar flares, Earth’s magnetosphere and laboratory applications, and more recently in the context of high-energy astrophysical systems. In high-energy astrophysical systems such as pulsar wind nebulae and relativistic jets from black holes, neutron stars, and their merging systems, it is expected that the magnetization parameter sigma can be much larger than unit. Magnetic reconnection is thought to be the driver for energy release and particle acceleration in the magnetically dominated regime.

These recent progresses have strong implications to high-energy plasma astrophysics. However, in most of studies the effect of radiation cooling may be important but not studied. The effect of radiation cooling on reconnection physics is an important problem in several extreme phenomena in high-energy plasma astrophysics, but its nature remains to be explored. We propose to use large-scale first-principle kinetic simulations including the radiation cooling to study the fundamental aspects of reconnection physics and particle acceleration processes. While most of studies focused on the cases with equal plasma conditions on both side of the current sheet, magnetic reconnection may occur at plasma boundary layers where magnetic fields and plasma flow can be significantly different. we will further study the relativistic reconnection under extreme conditions when there exists significant amount of magnetic shear and velocity shear.

Hui Li, LANL Staff Scientist
Xiangrong Fu, NMC Research Scientist

As part of the DoE/OFES project at LANL, this project performs advanced numerical simulations to study the current sheets and particle energization in turbulent plasmas. This has applications for space, solar and astrophysical plasmas. Dr. Xiangrong Fu from the NMC has developed hybrid and kinetic simulation techniques that can contribute to this project. He shall utilize these codes to study the effects of turbulence on particle energization and identify possible applications of these processes in systems such as solar wind, solar corona and accretion disk corona. This is an important part of our DoE/OFES project.