Nascap-2k Simulations of a VLF Plasma Antenna
Abstract
The response of a plasma to very low frequency (VLF) (3 kHz to 20 kHz) antennas at orbital altitudes of 1000 to 10,000 kilometers has been a subject of scientific interest for many decades. As this antenna frequency is less than either the plasma frequency or the electron gyrofrequency, (both nearly 300kHz for a plasma density of 10(exp 9) cu cm and a magnetic field of 0.1 gauss), only certain modes can propagate as an electromagnetic (EM) wave, and the near field is dominated by electrostatic (ES) effects. Although a comprehensive self-consistent EM-ES simulation would be the desired goal, there are many computational challenges to be overcome, so we begin with a quasi-static simulation so as to sort out the dominant ES effects. We present antenna simulations using Nascap-2k modeling the plasma using both an explicit Particle-in-cell (PIC) approach and a hybrid approach with PIC ions and fluid barometric electron densities. In the latter, electron plasma oscillations are suppressed, while in the former they are excited. Accuracy of the simulations is assessed by comparison with lower-dimensional simulations of similar cases.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 2005
- Accession Number
- ADA473320
Entities
People
- A. T. Wheelock
- C. Roth
- D. L. Cooke
- Myron J. Mandell
- Victoria A. Davis
Organizations
- Air Force Research Laboratory