Marek Gołkowski

Polarization of Narrowband VLF Transmitter Signals as an Ionospheric Diagnostic

Very low frequency (VLF, 3–30 kHz) transmitter remote sensing has long been used as a simple yet useful diagnostic for the D region ionosphere (60–90 km). All it requires is a VLF radio receiver that records the amplitude and/or phase of a beacon signal as a function of time. During both ambient and disturbed conditions, the received signal can be compared to predictions from a theoretical model to infer ionospheric waveguide properties like electron density. Amplitude and phase have in most cases been analyzed each as individual data streams, often only the amplitude is used. Scattered field formulation combines amplitude and phase effectively, but does not address how to combine two magnetic field components. We present polarization ellipse analysis of VLF transmitter signals using two horizontal components of the magnetic field. The shape of the polarization ellipse is unchanged as the source phase varies, which circumvents a significant problem where VLF transmitters have an unknown source phase. A synchronized two-channel MSK demodulation algorithm is introduced to mitigate 90∘ ambiguity in the phase difference between the horizontal magnetic field components. Additionally, the synchronized demodulation improves phase measurements during low-SNR conditions. Using the polarization ellipse formulation, we take a new look at diurnal VLF transmitter variations, ambient conditions, and ionospheric disturbances from solar flares, lightning-ionospheric heating, and lightning-induced electron precipitation, and find differing signatures in the polarization ellipse.

Magnetospheric whistler mode ray tracing in a warm background plasma with finite electron and ion temperature

Whistler mode waves play a major role in the energy dynamics of the Earths magnetosphere. Numerical raytracing has been used for many years to determine the propagation trajectories of whistler mode waves from various sources, both natural and anthropogenic. Previous work has been under the ideal cold plasma assumption even though temperatures of the background ions and electrons are in the range of several eV. We perform numerical raytracing with the inclusion of finite electron and ion temperatures to more accurately model the plasma environment of the Earths magnetosphere. Finite temperature effects are found to play a significant role in the whistler mode refractive index surface only when the wave frequency is near the lower hybrid resonance frequency and the wave normal angle is oblique. In such cases, the primary effect on whistler mode propagation is to lower the refractive index magnitude and increase the group velocity with slight modifications to the ray trajectories. Landau damping is shown to increase slightly with the inclusion of finite temperature.

Principles of Plasma Physics for Engineers and Scientists: Preface

This unified introduction provides the tools and techniques needed to analyze plasmas, and connects plasma phenomena to other fields of study. Combining mathematical rigor with qualitative explanations, and linking theory to practice with example problems, this is a perfect textbook for senior undergraduate and graduate students taking a one-semester introductory course in plasma physics. For the first time, material is presented in the context of unifying principles, illustrated using organizational charts, and structured in a successive progression from single-particle motion to kinetic theory and average values, through to the collective phenomena of waves in plasma. This provides students with a stronger understanding of the topics covered, their interconnections, and when different types of plasma models are applicable. Furthermore, mathematical derivations are rigorous yet concise, so physical understanding is not lost in lengthy mathematical treatments. Worked examples illustrate practical applications of theory, and students can test their new knowledge with 90 end-of-chapter problems.

Principles of Plasma Physics for Engineers and Scientists: Plasma diffusion

1. Introduction 2. Single particle motion 3. Kinetic theory of plasmas 4. Moments of the Boltzmann equation 5. Multiple fluid theory of plasmas 6. Single fluid theory of plasmas: magnetohydrodynamics 7. Collisions and plasma conductivity 8. Plasma diffusion 9. Introduction to waves in plasmas 10. Waves in cold magnetized plasmas 11. Effects of collisions, ions and finite temperature on waves in magnetized plasmas 12. Waves in hot plasmas 13. Plasma sheath and the Langmuir probe Appendix A. Derivation of second moment of the Boltzmann equation Appendix B. Useful vector identities.

Principles of Plasma Physics for Engineers and Scientists: Single-particle motion

1. Introduction 2. Single particle motion 3. Kinetic theory of plasmas 4. Moments of the Boltzmann equation 5. Multiple fluid theory of plasmas 6. Single fluid theory of plasmas: magnetohydrodynamics 7. Collisions and plasma conductivity 8. Plasma diffusion 9. Introduction to waves in plasmas 10. Waves in cold magnetized plasmas 11. Effects of collisions, ions and finite temperature on waves in magnetized plasmas 12. Waves in hot plasmas 13. Plasma sheath and the Langmuir probe Appendix A. Derivation of second moment of the Boltzmann equation Appendix B. Useful vector identities.