Year: 2020
Type: article
Abstract: We study, by numerical and analytical means, the evolution of a collisionless plasma initiated between absorbing walls. The ensuing flow is described by rarefaction waves that travel inward from the boundaries, interact, and eventually vanish after crossing through, leading up to the asymptotic stage of the decay. Particle simulations indicate that the kinetic evolution strongly resembles one found in isentropic gas dynamics. Namely, a very gradual density profile forms in the expanding central region where the rarefaction waves interact, with an accompanying linear velocity profile. Asymptotically, the density falls off as 1/t. The density and the flux at the boundary show little variation over the period when rarefaction waves still exist. Plasma potential, on the other hand, drops quite rapidly (on the underlying ion-acoustic timescale) to less than initial electron temperature Te when over 70% of the particles still remain in the system. This is due to electron kinetics being governed by conservation of adiabatic invariant in a slowly varying potential well. Analytical model of the velocity distribution is presented to explain the simulations. The results have implications for afterglow plasmas used in material processing and also for ion-extraction devices. One property of potential interest is good uniformity of the decaying plasma that occurs after approximately one ion-acoustic time.
Source: Physics of Plasmas
DOI: 10.1063/5.0021833
Authors: A. V. Khrabrov, I. D. Kaganovich, J. Chen, H. Guo
Institutions: Princeton Plasma Physics Laboratory, Tsinghua University
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Awards: G1334233940, G1912174983, G2985213006, G4896746546, 1979-1502 GENERAL ELECTRIC (GC) GLOBAL RESEARCH - BASE AWARD
PROJECT ENTITLED ''INLINE GAS DISCHARGE TUBE BREAKER FOR MESHED MVDC GRIDS''
GE GLOBAL RESEARCH PROPOSES TO DEVELOP A GAS DISCHARGE TUBE (GDT) WITH A LOW-LOSS THERMIONIC CATHODE AS A FAST INLINE MEDIUM-VOLTAGE DIRECT-CURRENT (MVDC) CIRCUIT BREAKER. THE GUIDING MARKET FOR THE GDT BREAKER IS THE UP-RATING OF EXISTING MEDIUM-VOLTAGE ALTERNATING-CURRENT (MVAC) DISTRIBUTION CORRIDORS INTO A TRUE MESHED MVDC GRID, TO MEET GROWING POWER DEMANDS IN CONGESTED URBAN AREAS WITHOUT THE NEED TO CLEAR NEW RIGHTS-OF-WAY., G663282964, G969889393
OpenAlex ID: W3081409092