Plasma and Beam Physics Commons^™

String-Of-Pearls Measurements Of Supersonic Plasma Jets Using Magnetospheric Multiscale Satellites, Amelia Koth

Discovery Day - Daytona Beach

High-energy supersonic plasma jets form when the solar wind, which is a flow of charged particles from the Sun, slows down as it encounters Earth’s magnetic shield. Occasionally, the solar wind remains at supersonic speeds as it enters this region. This forms plasma jets that propagate toward Earth; these jets can carry strong magnetic fields, drive magnetic reconnection, and potentially initiate substorms that lead to auroral activity.   Previously studied plasma jets occurred when the interplanetary magnetic field (IMF) points southward. In contrast, this study focuses on northward IMF conditions, which are less understood, yet still capable of producing supersonic jets. …

Effects Of Coulomb Collisions On The Structures Of Fast Magnetosonic Shocks, Bo Farnell

Physics and Astronomy Undergraduate Senior Theses

We present fully kinetic particle-in-cell simulations demonstrating qualitative effects of binary Coulomb collisions on fast magnetosonic shocks. We find that with a sufficiently high collisional frequency, shock rippling and reformation can be inhibited, creating stationary, laminar shocks. We see that collisions rapidly bring the reflected population into equilibrium with the upstream population, adding credibility to existing theories that the separation of these two populations create these dynamical behaviors around the shock transition region. We also see that Ohmic heating from Coulomb collisions can suppress instabilities.

Information Theory Analysis Of The Solar Wind Magnetic Structures For Space Weather Prediction, Katherine Holland

Doctoral Dissertations and Master's Theses

Forecasting space weather at Earth is highly complicated, because of the limited measurements of the dynamic processes in the Sun that span multiple temporal, spatial, and energy-scales. The solar wind is a highly structured, multi-scale, evolving plasma and consists of coronal mass ejections (CMEs), stream interaction regions (SIRs), expanding flux tubes (Borovsky, 2008), and interplanetary magnetic field (IMF) discontinuities and fluctuations. The aim of this research is to improve our understanding of the evolution and dissipation of different scale-size solar wind magnetic structures as they move from the Sun-Earth Lagrange point 1 (L1) to Earth's bow shock and, ultimately, to …

Empirical Validation Of Einstein’S Coefficient For The Deflection Of Light Due To Gravitational Forces, Alexandra R. Mcdowell

Honors College Theses

Einstein’s formula to calculate the deflection angle of light through space as it interacts with gravity was introduced in his 1916 publication on general relativity. This was not a new idea, but his equation was, and it was correct. Just 3 years after this publication, it was empirically validated by Sir Arthur Eddington and Sir Frank Dyson. Since that experiment in 1919, at least seven others have been performed that also gave definitive answers in support of Einstein’s deflection constant of 1.751 arcseconds. The two most recent ones made groundbreaking contributions to this effort. The 2017 eclipse showed reproducible results …

Reconnection-Driven Electron Acceleration, Ripudaman Singh Nirwan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Magnetic reconnection converts the magnetic energy available in a plasma to the kinetic energy of its constituent particles. In the simplest case, it occurs between anti-parallel magnetic field lines meeting in a plane. Another variant known as ‘component reconnection’ involves field lines reconnecting at an angle, giving a non-zero magnetic field component perpendicular to the plane of reconnection. This component is known as the ‘guide field’ and it is normalized to the reconnecting field in the literature. The guide field controls the particle-scale dynamics of reconnection and influences the ensuing particle acceleration.

Component reconnection occurs in the Earth’s magnetosphere, along …

Three-Dimensional Spreading Of Magnetic Reconnection Between Non-Parallel Flux Ropes With A Guide Field, Regis John

Graduate Theses, Dissertations, and Problem Reports (ETD)

Magnetic reconnection is a fundamental plasma process that facilitates the rapid conversion of magnetic energy into particle acceleration, plasma flows, and heating. It plays a central role in explosive astrophysical events such as solar flares, where vast amounts of magnetic energy are released on short time scales. A key structure in many reconnection sites is the magnetic flux rope, a column of plasma carrying current threaded by helical magnetic fields, which is frequently involved in or generated by reconnection. Understanding how reconnection unfolds in such flux rope systems is critical for interpreting both space weather phenomena and laboratory plasma dynamics. …

Modeling Energetic Electron Precipitation: Radiation Belt Loss, Its Drivers, And Atmospheric Impacts, Zhi Gu Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

Energetic electrons in the terrestrial outer radiation belt present significant hazards to spacecraft systems and human operations in space. The intensity of these electrons can vary rapidly and dramatically during geomagnetic storms, governed by a complex competition between acceleration and loss processes. Among these, precipitation into the atmosphere via resonant wave-particle interaction acts as a key loss mechanism. This dissertation focuses on improving the quantification of energetic electron precipitation using physics-based modeling constrained by low-altitude satellite observations.

We begin by developing and validating the Drift-Diffusion model, which simulates low-altitude electron dynamics while accounting for azimuthal drift, pitch-angle diffusion, and atmospheric …

On The Nature Of Low-Frequency Power Spectra In Solar Wind Turbulence, Mason Alden Dorseth

Theses and Dissertations

An important challenge in the accurate estimation of power spectra of plasma fluctuations in the solar wind at very low frequencies is that it requires extremely long signals, which will necessarily contain a mixture of qualitatively different solar wind streams. This unavoidably affects the structure of the power spectra by conflating all these different properties into a single power spectrum. This work develops a conditional statistical analysis to accurately estimate the power spectrum at arbitrarily low frequencies for ``pure'' slow solar wind stream, based on estimated autocorrelation functions of signals excluding portions that do not satisfy the required conditions. The …

Identifying Ion-Scale Waves In Parker Solar Probe Sub-Alfvénic Intervals, Nicholas Henry Androski, Kristoff Paulson

Physics

Identification of coherent quasi-parallel ion-scale (1-32 Hz) wave activity in sub-Alfvénic regions of the solar wind observed by NASA's Parker Solar Probe during perihelion encounters 8 to 16. Wave activity is filtered computationally by coherency, circular polarization and propagation angle with respect to the mean magnetic field. Initial statistical results are presented with suggestions for future improvements and studies. A general overview of the heliosphere and the context of ion-cyclotron waves (an ion-scale wave) in the coronal heating problem. Along the way to identify ion-scale wave activity, tables of sub-Alfvénic intervals and current sheet crossings for encounters 8 to 16 …

Kinetic Modeling Of Ionospheric Outflows Observed By The Visions-1 Sounding Rocket, Robert M. Albarran Ii

Doctoral Dissertations and Master's Theses

Plasma escape from the high-latitude ionosphere (ion outflow) serves as a significant source of heavy plasma to magnetospheric plasma sheet and ring current regions. Outflows alter mass density and reconnection rates, hence global responses of the magnetosphere. The VISIONS-1 (VISualizing Ion Outflow via Neutral atom imaging during a Substorm) sounding rocket was launched on Feb. 7, 2013 at 8:21 UTC from Poker Flat, Alaska, into an auroral substorm with the objective of identifying the drivers and dynamics of nightside ion outflow at altitudes where it is initiated, below 1000 km. Energetic ion data from the VISIONS-1 polar cap boundary crossing …

Mms Observations Of The Kelvin-Helmholtz Instability And Associated Ion Scale Waves, Rachel C. Rice

Doctoral Dissertations and Master's Theses

The detailed mechanisms coupling the solar wind to Earth's magnetosphere are not yet fully understood. Solar wind plasma is heated non-adiabatically as it penetrates the magnetosphere, and this process must span scale sizes. Reconnection alone is not able to account for the observed heating; other mechanisms must be at work. One potential process is the Kelvin-Helmholtz instability (KHI). The KHI is a convective instability which operates at the fluid scale in plasmas, but is capable of driving secondary process at smaller scales. Previous work has shown evidence of magnetic reconnection, various ion scale wave modes, mode conversion, and turbulence associated …

Solar Radio Burst Type Ii And Iii With Half Wave Dipole Antenna, Mohd Pauzi Farah Aqilah

Student Works (2020-2029)

An investigation into the physics of solar radio burst type II was done to understand the frequency gap between its fundamental and harmonic emissions that happen as aftershocks of Coronal Mass Ejection (CME). Up until now, the evolution of type II and its associated coronal wave still remain a mystery. Hazardous CME study upholds its fore coming danger to human and technology. This work also addresses the issue of the lack of spatial resolution of previous solar radio burst type II studies. An instrument produced by ETH Zürich namely the Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Spectrometers …

The Undeniable Attraction Of Lunar Swirls, Dany Waller

Posters-at-the-Capitol Presentations

Lunar swirls are complex patterns on the Moon with distinct brightness signatures and magnetic characteristics. Current research has suggested that the formation of lunar swirls relies on local magnetic fields to shield impinging solar wind, based on a shift in electromagnetic wavelength peaks related to solar radiation and space weathering. Our research combined recent models and methods to characterize these anomalies at the surface of the Moon, exploring the effects of field strength and position. We have produced a high resolution map of a famous swirl named Reiner Gamma using magnetic dipole modeling. These maps and models are considered when …

The Undeniable Attraction Of Lunar Swirls, Cierra Waller, Dhananjay Ravat

Posters-at-the-Capitol

Lunar swirls are complex patterns on the Moon with distinct brightness signatures and magnetic characteristics. Current research has suggested that the formation of lunar swirls relies on local magnetic fields to shield impinging solar wind, based on a shift in electromagnetic wavelength peaks related to solar radiation and space weathering. Our research combined recent models and methods to characterize these anomalies at the surface of the Moon, exploring the effects of field strength and position. We have produced a high resolution map of a famous swirl named Reiner Gamma using magnetic dipole modeling. These maps and models are considered when …

The Magnetopause: Bringing Space Physics Into A Junior Lab, Jim Crumley, Ari Palczewski,, Stephen Kaster

MapCores Faculty Publications

Undergraduate students often have minimal exposure to many subfields
of physics which are active areas of research. Space physics
is an area that is particularly difficult to expose students to since
it builds off of another area that most undergraduates see little of,
plasma physics. The magnetopause is convenient entry point
into space physics, since it can be modeled as a pressure balance, which is
a concept familiar from introductory physics. We use the Earth's
magnetopause as the basis for a lab for junior physics majors. In
the lab students analyze results from a NASA MHD simulation and
data from …