Showing papers by "Lou-Chuang Lee published in 1998"
TL;DR: In this paper, the ion pickup process in a regime very different from what has been investigated before is discussed, where newly created ions that result from ionization of neutral atoms can be accelerated, and background thermal ions can be intensely heated when they interact with the excited Alfven waves.
Abstract: It is well known that freshly created ions can be picked up by a moving plasma via self-consistently excited Alfven waves, as discovered in cometary physics in the late 1980s. This paper discusses the ion pickup process in a regime very different from what has been investigated before. We show that such a process can occur inside a magnetic reconnection layer. We suggest that this process might explain the origin of solar energetic ions associated with flares. In order to demonstrate that the acceleration process is rapid and efficient, a series of numerical simulations are carried out for the parameter regime relevant to solar active regions in the lower corona. Simulation results show that not only can the newly created ions that result from ionization of neutral atoms be accelerated, but the background thermal ions can be intensely heated as well when they interact with the excited Alfven waves.
20 citations
TL;DR: In this article, a new approach is proposed to identify mirror waves based on the 90 degrees phase difference between the magnetic field and plasma fluctuations, which is independent of Doppler shift.
Abstract: A new approach is proposed to identify mirror waves based on the 90 degrees phase difference between the magnetic field and plasma fluctuations. Magnetosheath observations, the linear MHD theory, and one-dimensional hybrid simulations support that the 90 degrees phase difference is a special character for mirror waves. This phase difference is independent of Doppler shift which means that our result remains the same in both the satellite (laboratory) and the plasma frames of reference. Therefore it is useful to distinguish mirror waves from slow waves which also have an anticorrelation (i.e., 180 degrees out of phase) relationship between magnetic field strength and plasma density fluctuations. The time evolution in the later stage shows that the dominant perturbed components are the magnetic field fluctuation along the background magnetic field B-0 and the velocity fluctuation perpendicular to B-0 and the wave vector k. A higher coherence and a stable 90 degrees phase difference between these two dominant components are found as time increases. The coherence between this velocity component and the plasma density is also high with a 90 degrees phase difference. A tendency is found that the longer wavelengths are progressively generated when mirror waves grow in simulation.
14 citations