Plasma and Beam Physics Commons^™

Modeling Velocity Distributions Of Interstellar Neutral Hydrogen In The Heliosphere, Lucas Robert Dyke

Dartmouth College Ph.D Dissertations

As interstellar neutral hydrogen (ISN H) is the most abundant neutral element in the helio- sphere, the region within which the solar wind interacts with the portion of the interstellar medium through which our solar system moves through, it is integral that we aim to under- stand its many properties and interactions within this region. This work details the synthesis and use of a model of ISN H, using trajectory methods to backtrace from a target point at a radial distance of 1 au where explorer probes like Interstellar Boundary Explorer (IBEX) and Interstellar Mapping and Acceleration Probe (IMAP) reside. …

Developing A Workforce To Build A Star On Earth, Vola Andrianarijaona, Angelina Castillo, Sean Walters

Campus Research Month

This study is meant to help understand why fusion has remained "30 years away" for decades and why that may finally be changing.We see nuclear fusion not merely as a physics phenomenon, but as a complex engineering challenge requiring coordination across different disciplines, including physics, materials science, electrical and mechanical engineering, systems engineering, robotics, and computer science, etc. Indeed, nuclear fusion is not just about "making atoms fuse"—it's about controlling, powering, measuring, and stabilizing one of the most extreme environments humans have ever built. Advances in superconducting magnets, new materials are bringing fusion closer to reality than ever before, and …

High-Latitude Ionospheric Irregularities Characterized Through Machine Learning Methods, Anna-Marie Bals

Doctoral Dissertations and Master's Theses

This study uses Machine Learning and data-driven techniques to understand plasma irregularities in high-latitude regions better. By combining observations and recent findings from modeling, the goal is to identify and classify scintillation signatures caused by different types of irregularities in the ionosphere. The focus is on irregularities from electron precipitation in the auroral oval and ExB drifts in the polar cap. Using Machine Learning tools, the study aims to distinguish between different scintillation signatures and link them to their sources, improving our ability to detect and characterize these events. Using multiple instruments and advanced filtering, the aim is to enhance …

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. …

On The Ubiquity, Properties And Evolution Of Small-Scale Magnetic Flux Ropes In The Heliosphere, Hameedullah Farooki

Dissertations

The solar wind is a plasma constantly blowing out from the Sun with a large-scale magnetic field having significant local complexity at small scales. Small-scale magnetic flux ropes (SMFRs), plasma structures with twisted field lines, are an important element of this complexity. This dissertation contributes several studies that further our understanding of SMFRs. The first study applies machine learning to measurements from Wind labeled by the presence of SMFRs and magnetic clouds (MCs). MCs were distinguished from non-MFRs with an AUC of 94% and SMFRs with an AUC of 89% and had distinctive plasma properties, whereas SMFRs appeared to be …

Next-Generation Alpha Irradiation Platform: Design, Development, And Applications In Radiobiological Research, Harsh Arya

Physics Dissertations - Archive

This dissertation unveils the innovative design, development, and application of a next-generation alpha irradiation platform, specifically crafted for pre-clinical and university-level radiobiological research. Driven by the quest to overcome the inherent limitations of existing alpha particle irradiators, this study explores the profound therapeutic potential of alpha particles in cancer treatment. Known for their exceptional high linear energy transfer (LET), alpha particles exhibit a unique prowess in inducing clustered DNA damage, sparking intriguing possibilities for highly targeted cancer therapies. Yet, their application has been historically constrained by their limited range of biological tissues and the absence of precise delivery systems.

Our …

Strong Ultrafast Demagnetization Due To The Intraband Transitions, G. P. Zhang, Mitsuko Murakami

Symposium Projects

Demagnetization in ferromagnetic transition metals driven by a femtosecond laser pulse is a fundamental problem in solid state physics, and its understanding is essential to the development of spintronic devices. Ab initio calculation of time-dependent magnetic moment in the velocity gauge so far has not been successful in reproducing the large amount of demagnetization observed in experiments. In this work, we propose a method to incorporate intraband transitions within the velocity gauge through a convective derivative in the crystal momentum space. Our results for transition-element bulk crystals (bcc Fe, hcp Co and fcc Ni) based on the time-dependent quantum Liouville …

Adaptive Plasmonic Metasurfaces For Radiative Cooling And Passive Thermoregulation, Azadeh Didari-Bader, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri

Engineering Faculty Articles and Research

In this work, we investigate a class of planar photonic structures operating as passive thermoregulators. The radiative cooling process is adjusted through the incorporation of a phase change material (Vanadium Dioxide, VO₂) in conjunction with a layer of transparent conductive oxide (Aluminum-doped Zinc Oxide, AZO). VO₂ is known to undergo a phase transition from the “dielectric” phase to the “plasmonic” or “metallic” phase at a critical temperature close to 68°C. In addition, AZO shows plasmonic properties at the long-wave infrared spectrum, which, combined with VO₂, provides a rich platform to achieve low reflections across the …

Classification Of Pixel Tracks To Improve Track Reconstruction From Proton-Proton Collisions, Kebur Fantahun, Jobin Joseph, Halle Purdom, Nibhrat Lohia

SMU Data Science Review

In this paper, machine learning techniques are used to reconstruct particle collision pathways. CERN (Conseil européen pour la recherche nucléaire) uses a massive underground particle collider, called the Large Hadron Collider or LHC, to produce particle collisions at extremely high speeds. There are several layers of detectors in the collider that track the pathways of particles as they collide. The data produced from collisions contains an extraneous amount of background noise, i.e., decays from known particle collisions produce fake signal. Particularly, in the first layer of the detector, the pixel tracker, there is an overwhelming amount of background noise that …

Lattice Optics Optimization For Recirculatory Energy Recovery Linacs With Multi-Objective Optimization, Isurumali Neththikumara, Todd Satogata, Alex Bogacz, Ryan Bodenstein, Arthur Vandenhoeke

College of Sciences Posters

Beamline optics design for recirculatory linear accelerators requires special attention to suppress beam instabilities arising due to collective effects. The impact of these collective effects becomes more pronounced with the addition of energy recovery (ER) capability. Jefferson Lab’s multi-pass, multi-GeV ER proposal for the CEBAF accelerator, ER@CEBAF, is a 10- pass ER demonstration with low beam current. Tighter control of the beam parameters at lower energies is necessary to avoid beam break-up (BBU) instabilities, even with a small beam current. Optics optimizations require balancing both beta excursions at high-energy passes and overfocusing at low-energy passes. Here, we discuss an optics …

Comparing Twins Ion Temperature Maps With Mms, Ampere, And Themis Observations During July 26, 2017 Reconnection Event, Isabella M. Householder

Honors Theses and Capstones

The solar wind releases a constant stream of ionized particles into space which causes complex behaviors to occur within Earth’s magnetosphere. These disruptions can initiate magnetic reconnection and cause flow reversal of ions in the magnetotail. Two flow reversal events were locally detected by the Magnetospheric Multiscale Mission (MMS) on July 26, 2017 at 0700 UT and 0730 UT. The Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) provide a global measurement of heated signatures of the magnetic field and detected an increase in ion temperature during these reconnection events without the presence of a geomagnetic storm. Active Magnetosphere and Planetary Electrodynamics …

Radio Diagnostics Of Particles And Plasma In The Solar Corona, Sherry Chhabra

Dissertations

Radio diagnostics, in addition to their capabilities in exploring intense, impulsive bursts, also provide a high sensitivity to much weaker events, which may not show any substantial signature in other wavelengths.

The initial case study examines a complex event consisting of multiple radio sources/bursts associated with a fast coronal mass ejection (CME) and an M 2.1 class solar flare (SOL2015-09-20). ‘First-light’ data from the Owens Valley Radio Observatory–Long Wavelength Array is put in context with observations from Large Angle and Spectrometric Coronagraph onboard the Solar and Heliospheric Observatory, along with the WAVES radio spectrograph onboard WIND, the Expanded Owens Valley …

Optimizing Llrf Parameters In The Electron-Ion Collider, William M. Bjorndahl

Physics

To improve particle interaction in the future Electron-Ion Collider (EIC), we investigated different feedback implementations to control the accelerating voltage and examined the power and beam phase for each instance. Using MATLAB, we studied three feedback mechanisms: Direct, One Turn, and Feedforward. Enacting feedforward yielded the best performance. To minimize the klystron power consumption, we analyzed different Low-Level Radio Frequency (LLRF) parameters such as detuning. Combining theory and simulated results, we found the optimal detuning value that minimizes klystron power consumption.

The Population Densities Of Argon Metastable Levels, Nada Khogeer, Chelsy Gonzalez, Milka Nikolic

Physics and Astronomy

In this experiment, we used the optical emission spectroscopy (OES) method to obtain the main properties of low temperature Argon plasma. The experiment was sustained in powers and pressures that ranges from 30-100 W and 15-100 mTorr. We used numerical methods for the Argon kinetic model to calculate metastable levels and resonant states for the first excited states in low temperature Argon plasma. By finding the ratio of two spectral lines and finding another ratio from a different upper energy level that goes down to the same two lower energy levels, we can construct a system of two nonlinear equations. …

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 …

Power-Recycled Weak-Value-Based Metrology, Kevin Lyons, Justin Dressel, Andrew N. Jordan, John C. Howell, Paul G. Kwiat

Mathematics, Physics, and Computer Science Faculty Articles and Research

We improve the precision of the interferometric weak-value-based beam deflection measurement by introducing a power recycling mirror, creating a resonant cavity. This results in all the light exiting to the detector with a large deflection, thus eliminating the inefficiency of the rare postselection. The signal-to-noise ratio of the deflection is itself magnified by the weak value. We discuss ways to realize this proposal, using a transverse beam filter and different cavity designs.

Quantitative Assessment Of Blood Coagulation By Cold Atmospheric Plasma, Caitlin Heslin, Daniela Boehm, Vladimir Milosavljevic, Michelle Laycock, Patrick J. Cullen, Paula Bourke

Articles

Cold atmospheric plasma (CAP) is produced by ionizing a chosen gas, thereby creating charged and reactive species. The reactive species generated are capable of inducing a range of biomedically relevant interactions including blood coagulation. However, the underlying biochemical processes of plasma-assisted blood coagulation are largely unknown, and data quantifying blood clot formation or the impact of system parameters on the intensity of the blood clot are scarce. In this study, blood coagulation was quantified by measuring hemoglobin absorbance. System parameters of the kINPen plasma jet were investigated and compared, including treatment time, distance from the plasma source and gas flow …

Gaussian Beam Steering On A Target Plane Via High Speed Orthogonal Mirror-Mounted Galvanometers, Keith Gresiak

Physics

No abstract provided.

Operation Characteristics And Bio Application Of An Atmospheric Dielectric Barrier Discharge., Chee Kin Lai

Student Works (2010-2019)

This research project involved the construction of a dielectric barrier discharge (DBD) system capable of producing low temperature plasma at atmospheric pressure. The DBD was characterized for the purpose of investigating the effectiveness of low temperature plasma for inactivation of bacteria such as Escherichia coli, Salmonella enteritidis, and Bacillus cereus. The discharge was ignited in the air gap between two parallel copper disc electrodes (3.8cm diameter each) where one of the electrodes was insulated by a dielectric barrier. Glass ( thickness = 2mm) and alumina ( thickness = 1.0mm) were used as the barrier. The DBD was powered by a …

Investigation Of Track-Cluster Matching Vs Track-Cell Matching In The Alice Detector At Cern, Kevin Coulombe

Physics

The ALICE (A Large Ion Collider Experiment) Experiment is a detector that is one of four stationed at the CERN Large Hadron Collider. The goal of ALICE is to investigate the properties of the quark-gluon plasma, a new form of matter which only existed during the first microsecond of the Universe. ALICE measures the aftermath of the collision of two lead ions. Some information detected is the trajectory of the particles traveling through the tracking detectors and energy deposited in the calorimeters. Both the tracks and energy are required to determine the identities of the various particles as they travel …

Energy Losses Of Solar Neutrinos, Zamri Zainal Abidin

Student Works (2000-2009)

Using the stopping power of matter. the effects of oscillations on the energy losses of solar neutrinos are investigated. The adiabatic and non-adiabatic survival probabilities of the neutrino oscillations, the mixing angles and Am² are the parameter.; in the calculations. The total energy losses for ⁸B neutrinos with maximum spectral energy of 14.06 MeV is 5 x 10⁻⁷ MeV and is slightly lower than the losses from the non-adiabatic conversion which is ~7 x 10⁻⁷ MeV. From the calculation, we found that the maximum total energy loss for solar neutrinos is of the order 10⁻⁶ MeV. We also include the …