Digital Commons Network^™

An Evaluation On The Uncertainty For The Routine Of Dosimetry Calibration At The National Secondary Standard Dosimetry Laboratory, Albania, Klotilda Nikaj

International Journal of Nuclear Security

Every employer must, in relation to any work with ionizing radiation that they undertake, take all necessary steps to restrict so far as is reasonably practicable the extent to which their employees and other persons are exposed to ionizing radiation. This goal leads to an increased awareness about the proper maintenance and annual calibration of the personal dosimeters to ensure an accurate and precise radiation dose. The present work has described the performance of the radiation system of the ¹³⁷Cs source at the National Secondary Standard Dosimetry Laboratory (SSDL), located at the Institute of Applied Nuclear Physics at the …

Neutron Star Low-Mass X-Ray Binaries In And Out Of Focus: Nustar Stray Light, Songwei Li

Wayne State University Dissertations

Neutron star low-mass X-ray binaries (NS LMXBs) provide crucial insights into the physics of accretion under extreme gravity. In this dissertation, we explore the capabilities of NuSTAR’s stray light (SL) observations to supplement, and in some cases, surpass focused data in spectral studies of bright LMXBs. Utilizing the use of SL datasets, we perform detailed spectral analyses of two Z sources: GX 340+0 and Sco X-1.

For GX 340+0, we compare 7 focused and 25 SL observations across multiple spectral states, demonstrating that SL data significantly expand temporal coverage and allow for the detection of long-term spectral evolution not evident …

A Random Walk Simulation Of Positron Annihilation Depth As A Function Of Positron Beam Energy, Saniya Anjum Aqeel Ahmed Yadgeer

Physics Theses - Archive

Depth resolved defect and chemical characterization studies using positron annihilation spectroscopy depend on the ability to estimate the fraction of positrons annihilating at surface, in the bulk, at defects or as Positronium. The depth resolution is limited by the implantation profile of the energetic positrons and the diffusion of the thermalized positrons. Here we implement a random walk simulation as described in S. Eichler et al. [1] to track the monoenergetic positrons implanted into multilayer graphene on Cu. For our simulations the implantation depths were sampled from a Makhovian distribution that has been shown to accurately represent the implantation profile …

Measurement Of Two-Point Energy Correlators Within Jets In P+P Collisions At Sqrt[S]=200  Gev, Star Collaboration

Physics and Astronomy Faculty Publications

Hard-scattered partons ejected from high-energy proton-proton collisions undergo parton shower and hadronization, resulting in collimated collections of particles that are clustered into jets. A substructure observable that highlights the transition between the perturbative and nonperturbative regimes of jet evolution in terms of the angle between two particles is the two-point energy correlator (EEC). In this Letter, the first measurement of the EEC at RHIC is presented, using data taken from 200 GeV p þ p collisions by the STAR experiment. The EEC is measured both for all the pairs of particles in jets and separately for pairs with like and …

Design And Construction Of An Affordable Adjustable Repetition Rate Optical Frequency Comb, Christopher Latchford

Physics, Astronomy and Geophysics Honors Papers

Two different adjustable repetition rate optical frequency combs were designed and constructed with off-the-shelf components, including several improvements to established erbium fiber designs. These designs were assembled at a fraction of the cost of a commercial comb. Both combs were constructed with a repetition rate of roughly 100 MHz, with one combs tuning range being 2 MHz and the others being 3 MHz. These combs followed different designs, the first being a modification of an established nonlinear polarization rotation (NPR) design, the second being a modification to a “figure 9” design. A stabilization control loop for frep achieved long-term drifts …

A Fault-Tolerant Exchange-Coupled Spin-Ensemble Qubit At Elevated-Temperatures, Aniruddha Chakraborty

Theses and Dissertations

This thesis introduces a novel qubit architecture: the ferromagnetic exchange-coupled spin ensemble qubit (E-qubit), designed to address the noise-induced instability. In this work, the time evolution of the ensemble’s density matrix is studied using the Liouville–von Neumann equation. To benchmark against a single-spin qubit, the gate fidelity of an E-qubit is computed in the presence of thermal noise. Coherence time is also analyzed under identical thermal condition and a linear scaling is observed with qubit size . The results show that, at 6 K , the gate fidelity error (0.7 % ) of the seven- spin ensemble is an order …

Reasoning Through Change: Exploring Covariational Thinking In Student Exponential Graph Interpretation, Samantha Lynn Pearson

Honors Theses and Capstones

This study explores how life science students reason about exponential functions in the context of an introductory physics course. While exponential functions are essential in both physics and biology—appearing in scenarios like population growth and temperature cooling—students often encounter challenges in interpreting them. Using a resources framework, we examined the cognitive resources these students bring to exponential reasoning, focusing on what ideas and strategies they already possess. Our methodology involved conducting think-aloud interviews with nine students from PHYS 402. Interviews were coded using a framework informed by prior research on covariational reasoning and exponential understanding. Results show that students generally …

Cfd Analysis Of Hydrodynamic Cavitation Through An Orifice: Influence Of Different Inlet Pressures And Number Of Orifice Holes, Lemthong Chanphavong, Vongsavanh Chanthaboune, Keophousone Phonhalath

ASEAN Journal on Science and Technology for Development

Hydrodynamic cavitation (HC) is considered an energy-efficient process with high potential for utilization in many chemical processes. This study presents a computational fluid dynamics (CFD) analysis of cavitating flow through an orifice with a constant flow area. The Reynolds-Averaged Navier-Stokes (RANS) equations, coupled with turbulence and cavitation models, are employed to capture the complex flow behaviors. The effects of inlet pressures and number of orifice-holes on cavitation behavior are investigated. Result of the numerical simulation is validated with the existing experimental data from the literature. The CFD study revealed that cavitation initiates just behind the inlet edge of the orifice …

Nonperturbative Aspects Of The Electromagnetic Pion Form Factor At High Energies, K. Quirion, C. Fernandez-Ramirez, V. Mathieu, G. Montaña, R. J. Perry, A. Pilloni, A. Rodas, V. Shastry, W. A. Smith, A. P. Szczepaniak, D. Winney

Physics Faculty Publications

The structure of hadronic form factors at high energies and their deviations from perturbative quantum chromodynamics provide insight on nonperturbative dynamics. Using an approach that is consistent with dispersion relations, we construct a model that simultaneously accounts for the pion wave function, gluonic exchanges, and quark Reggeization. In particular, we find that quark Reggeization can be investigated at high energies by studying scaling violation of the form factor.

Background-Field Method And Qcd Factorization, Ian Balitsky

Physics Faculty Publications

One method for deriving a factorization for QCD processes is to use successive integration over fields in the functional integral. In this approach, we separate the fields into two categories: dynamical fields with momenta above a relevant cutoff, and background fields with momenta below the cutoff. The dynamical fields are then integrated out in the background of the low-momentum background fields. This strategy works well at tree level, allowing us to quickly derive QCD factorization formulas at leading order. However, to extend the approach to higher loops, it is necessary to rigorously define the functional integral over dynamical fields in …

Flavor Dependence Of Charged Pion Fragmentation Functions, H. Bhatt, P. Bosted, S. Jia, W. Armstrong, D. Dutta, R. Ent, D. Gaskell, E. Kinney, H. Mkrtchyan, S. Ali, R. Ambrose, D. Androić, C. Ayerbe Gayoso, A. Bandari, V. Berdnikov, D. Bhetuwal, D. Biswas, M. Boer, E. Brash, A. Camsonne, M. Cardona, J. P. Chen, J. Chen, M. Chen, E. M. Christy, S. Danagoulian, M. Diefenthaler, S. Covrig, B. Duran, M. Elaasar, C. Elliot, H. Fenker, E. Fuchey, J. O. Hansen, F. Hauenstein, T. Horn, G. M. Huber, M. K. Jones, M. L. Kabir, A. Karki, B. Karki, S. J. D. Kay, C. Keppel, V. Kumar, N. Lashley-Colthirst, W. B. Li, D. Mack, S. Malace, P. Markowitz, M. Mccaughan, E. Mcclellan, D. Meekins, R. Michaels, A. Mkrtchyan, G. Niculescu, I. Niculescu, B. Pandey, S. Park, E. Pooser, B. Sawatzky, G. R. Smith, H. Szumila-Vance, A. S. Tadepalli, V. Tadevosyan, R. Trotta, H. Voskanyan, S. A. Wood, Z. Ye, C. Yero, X. Zheng

Physics Faculty Publications

We have measured the flavor dependence of multiplicities for π⁺ and π⁻ production in semi-inclusive deep-inelastic scattering (SIDIS) on proton and deuteron to explore a possible charge symmetry violation in fragmentation functions. The experiment used an electron beam with energies of 10.2 and 10.6 GeV at Jefferson Lab and the Hall-C spectrometers. The electron kinematics spanned the range 0.3 < x < 0.6, 2 < Q² < 5.5 GeV², and 2.2 < W < 3.2 GeV. The pion fractional momentum range was 0.3 < z < 0.7, and the transverse momentum range was 0 < p_T < 0.25 GeV/c. Assuming factorization and allowing for isospin breaking, the results can be described by two “favored” and two “unfavored” effective low p_T fragmentation functions that are flavor-dependent. We find each pair converges to a common flavor-independent fragmentation function at the highest W, where factorization is most applicable.

Avenues For A Number Density Interpretation Of Dihadron Fragmentation Functions, T. Rogers, A. Courtoy

Physics Faculty Publications

In this letter, we reassess the underlying physics of the number sum rule for dihadron fragmentation functions. We will argue that, currently, there are no settled constraints on what constitutes a valid number density interpretation for multihadron fragmentation functions. Imposing overly restrictive criteria might lead to misinterpretating the data. Most importantly, and on the basis of phenomenological analyses, the slightly varying definitions used in previous work are not excluded from possessing legitimate number density interpretations (up to the usual issues with ultraviolet divergences and renormalization), so long as they are paired with appropriate factorization theorems. We advocate for further theoretical …

Sensitivity Analysis Of The 197 Mhz Prototype Crab Cavity For Eic, Subashini De Silva, Jean R. Delayen, B. Xiao, E. Drachuk, I. H. Senevirathne, A. Castilla, N. Huque, Z. Li

Physics Faculty Publications

The Electron-Ion Collider at BNL requires several crabbing systems that will be operating at 197 MHz and 394 MHz to compensate for the loss of luminosity due to the large crossing angle of the colliding beams. Two 197 MHz crab cavity cryomodules containing two cavities each will be installed in the Hadron Storage Ring (HSR) at the IP6 interaction region. Due to its large size compared to previously developed crabbing cavities, the 197 MHz crabbing cavity system was identified as one of the critical rf systems in the EIC. Therefore, a cavity has been designed including the ancillaries, and is …

First Measurement Of Near-Threshold And Subthreshold J/Ѱ Photoproduction Off Nuclei, J. R. Pybus, L. Ehinger, T. Kolar, B. Devkota, P. Sharp, B. Yu, M. M. Dalton, D. Dutta, H. Gao, O. Hen, E. Piasetzky, S. N. Santiesteban, A. Schmidt, A. Somov, H. Szumila-Vance, S. Adhikari, A. Asaturyan, A. Austregesilo, C. Ayerbe Gayoso, J. Barlow, V. V. Berdnikov, H. D. Bhatt, D. Bhetuwal, T. Black, W. J. Briscoe, G. Chung, P. L. Cole, A. Deur, R. Dotel, H. Egiyan, P. Eugenio, C. Fanelli, L. Gan, A. Gasparian, J. Guo, K. Hernandez, D. W. Higinbotham, P. Hurck, I. Jaegle, R. T. Jones, V. Kakoyan, A. Karki, H. Li, W. B. Li, G. R. Linera, V. Lyubovitskij, H. Marukyan, M. D. Mccaughan, M. Mccracken, K. Mizutani, D. Nguyen, S. Oresic, A. I. Ostrovidov, Z. Papandreou, C. Paudel, K. Peters, J. Ritman, A. Schick, J. Schwiening, A. Smith, S. Somov, I. Strakovsky, K. Suresh, V. V. Tarasov, S. Taylor, T. Xiao, Z. Zhang, X. Zhou

Physics Faculty Publications

We report on the first measurement of J/ψ photoproduction from nuclei in the photon energy range of 7 to 10.8 GeV, extending above and below the photoproduction threshold in the free proton of ∼8.2 GeV. The experiment used a tagged photon beam incident on deuterium, helium, and carbon, and the GlueX detector at Jefferson Lab to measure the semi-inclusive A(γ,e⁺e^-p) reaction with a dilepton invariant mass M(e⁺e^-)∼m_J/ψ=3.1 GeV. The incoherent J/ψ photoproduction cross sections in the measured nuclei are extracted as a function of the incident photon energy, momentum transfer, …

Emc Effect Of Tritium And Helium-3 From The Jlab Marathon Experiment, D. Abrams, H. Albataineh, B. S. Aljawmeh, S. Alsalmi, D. Androic, K. Aniol, W. Armstrong, J. Arrington, H. Atac, T. Averett, C. Ayerbe Gayoso, X. Bai, J. Bane, S. Barcus, A. Beck, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, D. Blyth, W. Boeglin, D. Bulumulla, J. Butler, A. Camsonne, M. Carmignotto, J. Castellanos, J. -P. Chen, I. C. Cloët, E. O. Cohen, S. Covrig, K. Craycraft, R. Cruz-Torres, B. Dongwi, B. Duran, D. Dutta, N. Fomin, E. Fuchey, C. Gal, T. N. Gautam, S. Gilad, K. Gnanvo, T. Gogami, J. Gomez, C. Gu, A. Habarakada, T. Hague, J. -O. Hansen, M. Hattawy, F. Hauenstein, D. W. Higinbotham, R. J. Holt, E. W. Hughes, C. Hyde, H. Ibrahim, S. Jian, S. Joosten, A. Karki, B. Karki, A. T. Katramatou, C. Keith, C. Keppel, M. Khachatryan, A. Khanal, A. Kievsky, D. King, P. M. King, I. Korover, S. A. Kulagin, K. S. Kumar, T. Kutz, N. Lashley-Colthirst, S. Li, W. Li, H. Liu, S. Liuti, N. Liyanage, P. Markowitz, R. E. Mcclellan, D. Meekins, S. Mey-Tal Beck, Z. -E. Meziani, R. Michaels, M. Mihovilovic, V. Nelyubin, D. Nguyen, Nuruzzaman, M. Nycz, R. Obrecht, M. Olson, V. F. Owen, E. Pace, B. Pandey, V. Pandey, M. Paolone, A. Papadopoulou, S. Park, S. Paul, G. G. Petratos, R. Petti, E. Piasetzky, R. Pomatsalyuk, S. Premathilake, A. J. R. Puckett, V. Punjabi, R. D. Ransome, M. N. H. Rashad, P. E. Reimer, S. Riordan, J. Roche, G. Salmè, N. Santiesteban, B. Sawatzky, A. Schmidt, B. Schmookler, S. Scopetta, J. Segal, E. P. Segarra, A. Shahinyan, S. Širca, N. Sparveris, T. Su, R. Suleiman, H. Szumila-Vance, A. S. Tadepalli, L. Tang, W. Tireman, F. Tortorici, G. M. Urciuoli, B. Wojtsekhowski, S. Wood, Z. H. Ye, J. Zhang

Physics Faculty Publications

Measurements of the EMC effect in the tritium and helium-3 mirror nuclei are reported. The data were obtained by the MARATHON Jefferson Lab experiment, which performed deep inelastic electron scattering from deuterium and the three-body nuclei, using a cryogenic gas target system and the high resolution spectrometers of the Hall A Facility of the Lab. The data cover the Bjorken x range from 0.20 to 0.83, corresponding to a squared four-momentum transfer Q² range from 2.7 to 11.9  (GeV/c)², and to an invariant mass W of the final hadronic state greater than 1.84  GeV/c². The tritium EMC effect measurement is …

New Measurements Of The Deuteron-To-Proton F₂ Structure-Function Ratio, D. Biswas, F. A. Gonzalez, W. Henry, A. Karki, C. Morean, A. Nadeeshani, A. Sun, Z. Ahmed, S. Alsalmi, W. Armstrong, A. Asaturyan, C. Ayerbe Gayoso, V. Berdnikov, H. Bhatt, D. Bhetuwal, P. Bosted, E. Brash, M. H. S. Bukhari, J. P. Chen, M. Chen, M. E. Christy, S. Covrig Dusa, K. Craycraft, S. Danagoulian, D. Day, M. Diefenthaler, M. Dlamini, J. Dunne, B. Duran, D. Dutta, R. Ent, H. Fenker, N. Fomin, E. Fuchey, D. Gaskell, T. N. Gautam, J. O. Hansen, F. Hauenstein, A. V. Hernandez, T. Horn, G. M. Huber, M. K. Jones, S. Joosten, M. L. Kabir, C. Keppel, A. Khanal, P. M. King, E. Kinney, M. Kohl, M. Lashley-Colthirst, S. Li, W. B. Li, A. H. Liyanage, D. Mack, S. Malace, P. Markowitz, J. Matter, D. Meekins, R. Michaels, A. Mkrtchyan, Z. Moore, S. J. Nazeer, S. Nanda, G. Niculescu, I. Niculescu, D. Nguyen, B. Pandey Nuruzzaman, S. Park, E. Pooser, A. J. R. Puckett, M. Rehfuss, J. Reinhold, B. Sawatzky, G. R. Smith, H. Szumila-Vance, A. S. Tadepalli, V. Tadevosyan, R. Trotta, S. A. Wood, C. Yero, J. Zhang

Physics Faculty Publications

Nucleon structure functions, as measured in lepton-nucleon scattering, have historically provided a critical observable in the study of partonic dynamics within the nucleon. However, at very large parton momenta, it is both experimentally and theoretically challenging to extract parton distributions due to the probable onset of nonperturbative contributions and the unavailability of high-precision data at critical kinematics. Extraction of the neutron structure and the d quark distribution have been further challenging because of the necessity of applying nuclear corrections when utilizing scattering data from a deuteron target to extract the free neutron structure. However, a program of experiments has been …

Multidimensional Measurements Of Beam Single-Spin Asymmetries In Semi-Inclusive Deep-Inelastic Charged-Kaon Electroproduction Off Protons In The Valence Region, Clas Collaboration, A. Kripko, S. Diehl, K. Joo, P. Achenbach, J. S. Alvarado, M. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, L. Baashen, N. A. Baltzell, L. Barion, L. Bashkanov, F. Benmokhtar, A. Bianconi, A. S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, K. -T. Brinkmann, W. J. Briscoe, W. K. Brooks, T. Cao, R. Capobianco, D. S. Carman, J. C. Carvajal, A. Celentano, P. Chatagnon, G. Ciullo, P. L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Dilks, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, S. Fegan, I. P. Fernando, A. Filippi, G. Gavalian, G. P. Gilfoyle, D. I. Glazier, R. W. Gothe, Y. Gotra, K. Hafidi, H. Hakobyan, M. Hattawy, F. Hauenstein, T. B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D. G. Ireland, E. L. Isupov, H. Jiang, H. S. Jo, T. Kageya, A. Kim, W. Kim, V. Klimenko, V. Kubarovsky, S. E. Kuhn, L. Lanza, P. Lenisa, X. Li, Z. Lu, I. J. D. Macgregor, D. Marchand, D. Martiryan, V. Mascagna, D. Matamoros, M. Maynes, B. Mckinnon, R. G. Milner, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, P. Nadel-Turonski, T. Nagorna, K. Neupane, D. Nguyen, S. Niccolai, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, L. L. Pappalardo, R. Paremuzyan, E. Pasyuk, S. J. Paul, N. Pilleux, S. Polcher Rafael, J. Poudel, J. W. Price, Y. Prok, T. Reed, M. Ripani, J. Ritman, C. D. Roberts, P. Rossi, A. A. Rusova, S. Schadmand, A. Schmidt, Y. G. Sharabian, E. V. Shirokov, S. Shrestha, U. Shrestha, D. Sokhan, N. Sparveris, M. Spreafico, I. I. Strakovsky, S. Strauch, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, T. Vittorini, H. Voskanyan, A. Vossen, E. Voutier, Y. Wang, D. P. Watts, U. Weerasinghe, X. Wei, M. H. Wood, L. Xu, S. -S. Xu, N. Zachariou, V. Ziegler, M. Zurek

Physics Faculty Publications

Measurements of beam single-spin asymmetries in semi-inclusive deep-inelastic electron scattering (SIDIS) with positively charged kaons off protons have been performed with 10.6 and 10.2 GeV incident electron beams using the CLAS12 spectrometer at Jefferson Lab. We report an analysis of the electroproduction of positively charged kaons over a large kinematic range of fractional energy, Bjorken x, transverse momentum, and photon virtualities Q² ranging from 1 GeV² up to 6 GeV². This is the first published multidimensionally binned CLAS12 measurement of a kaon SIDIS single-spin asymmetry in the valence quark regime. The data provide constraints on the structure function ratio …

Investigating The Roles Of Intrinsic Point Defects And Transition Metal Doping In Monolayer And Bulk Tis2, Patrick J. Keeney

UNF Graduate Theses and Dissertations

Within this thesis, the magnetic and electronic properties of various 1T-TiS₂ systems are thoroughly examined using density functional theory (DFT) and scanning tunneling microscopy (STM). Formation energies and electronic implications of intrinsic point defects in bulk TiS₂ and monolayer TiS₂ are analyzed by approximating a computational monolayer of TiS₂ as the surface layer of a bulk sample. This approximation is validated given that intralayer covalent bonding dominates interlayer van der Waals interactions. We conclude that the most energetically favorable intrinsic defects are Ti atoms settling above the outermost S plane and S vacancies. In addition, the …

Frustrated Quantum Magnetism: The Interplay Of Isotropic And Anisotropic Interactions With Application To Α-Rucl3, Evan M. Wilson

UNF Graduate Theses and Dissertations

We investigate how anisotropic spin interactions, including Dzyaloshinskii–Moriya and Kitaev terms, manifest across quantum spin systems ranging from a single S = 1/2 dimer to molecular spin clusters and layered magnetic materials. Beginning with an exact analysis of the spin dimer, we demonstrate how singlet–triplet mixing induced by Dzyaloshinskii–Moriya interaction directly influences both thermodynamic observables and inelastic neutron scattering spectra. These microscopic fingerprints are then extended to trimer, tetramer, and tetrahedron geometries, where field-induced phase transitions and heat capacity anomalies reveal the interplay between isotropic Heisenberg and anisotropic Kitaev exchanges. In the frustrated zigzag honeycomb lattice, we show that a …

Measuring Resistivity With Low-Cost 3-D Printed Four-Point Probe, Benjamin Siens

SPARK Symposium Presentations

Resistivity is an intrinsic property that determines how strongly electrical current is resisted. Measurement of the resistivity of materials is vital for many fields of science and engineering. This is easily accomplished with a four-point probe. However, commercial probes can be costly. Using 3-D printing and based on the design in Lu et al. (J. Chem. Educ. 2017), a functional four-point probe has been built at a much lower cost in materials. Additionally, the probe design has been simplified for easier construction and better compatibility with Belmont University’s 3- D printers. ITO glass was used to determine the accuracy of …

Fortifying Nuclear Security: Cultivating Vigilance Culture Among Personnel For Enhanced Prevention And Response, Sabariah Kader Ibrahim, Sonia Naz

International Journal of Nuclear Security

A vigorous nuclear security culture is crucial in preventing the theft and sabotage of nuclear material. It requires vigilance from all employees because relying solely on closed-circuit television systems and security personnel is insufficient to deter potential threats. Employee attentiveness plays a vital role in recognizing and preventing suspicious activities. However, achieving a strong security culture is challenging because of the lack of incidents in some facilities, leading to employee complacency.

This paper highlights the pivotal role of personnel in the success of nuclear security measures, emphasizing the need for a proactive and vigilant mindset among staff. Through the analysis …

Tidal Love Numbers For A Non-Rotating Two-Fluid Neutron Star: Interior Solution, Gregory G Jaurequi

Dissertations and Theses

We investigate the tidal Love numbers for a non-rotating dark matter admixed neutron star (NS). Tidal Love numbers, which quantify a star's response to the tidal field of a companion object, are an important feature in the gravitational wave (GW) signal and vary depending on the star’s equation of state and dark matter profiles. By determining how the internal properties of the NS affect the GW signal, we hope that improvements in gravitational wave detection will help constrain these parameters by providing additional data from neutron star mergers with other compact objects. To this end, we focus on solving the …

Co₂ Isotopologues From The Ace Satellite, D. English, P. Bernath, C. Boone

Chemistry & Biochemistry Faculty Publications

Carbon dioxide isotopologues have been studied thoroughly in the troposphere. In the stratosphere, the minor oxygen CO₂ isotopologues have anomalous abundances due to their exchange reactions with isotopically fractionated ozone, differentiating them from tropospheric CO₂. Previously a model predicted that this anomalous isotopic abundance continues into the mesosphere but lacked verification from experimental observations. Here we use the Atmospheric Chemistry Experiment Fourier Transform Spectrometer which records infrared transmittance spectra of the Earth's limb from low Earth orbit using solar occultation. These infrared spectra provide measurements of global CO₂ isotopologue volume mixing ratios (VMRs) from the upper troposphere to the lower …

The Requirements Of A Nuclear Propulsion System For The Human Exploration Of Mars, Scotia Rollins

Pitzer Senior Theses

This thesis investigates the propulsion requirements for a crewed mission to Mars, focusing on how mission architecture, particularly the choice between opposition- and conjunction-class trajectories, influences the selection between nuclear thermal propulsion (NTP) and nuclear electric propulsion (NEP). By applying the Tsiolkovsky rocket equation, the Delta-V (∆V) needed for efficient interplanetary transfers is shown to exceed the performance limits of chemical propulsion, motivating the need for nuclear alternatives. An engineering comparison of NTP and NEP systems evaluates key parameters including specific impulse, thrust, propellant mass fraction, system mass, and power-to-mass ratios. NTP provides high thrust but moderate efficiency, making it …

Nonlinear Wave Dynamics In Asteroseismology With Application To Delta Scuti Stars, Mohammed Mourabit

Physics Dissertations - Archive

This thesis compiles the collection of works in nonlinear astroseismology and its implication to the δ Sct variable that we carried over the course of five years. With the advent of high-resolution space missions such as the Kepler and TESS telescopes, we were able to see significant progress in the field in recent years. Nonetheless the new technologies also brought an increasing number of observation that are seemingly contradictory to the linear theory of asteroseismology. In particular, we find the δ Sct variable, which eludes our models in terms of how varied we find they spectra for stars with very …

From Plasmonics To Superfluorescence: Engineering Light- Matter Interactions For Quantum Optical Phenomena, Aaron J. Wildenborg

Dissertations, Master's Theses and Master's Reports

This work presents different ways to engineer light-matter interactions by using nanostructures to exploit quantum-optical phenomena. First, sodium (Na) is predicted to be an ideal plasmonic material due to its ultra-low optical losses from the visible to the near-infrared (NIR). However, Na has practical limitations due to its high chemical reactivity. Using a scalable fabrication method for Na plasmonic nanostructures by combining phase-shift photolithography and a thermo-assisted spin-coating process, we produced nano-pit arrays of varying periodicities (300-600 nm), supporting tunable surface plasmon polariton (SPP) modes spanning visible to NIR. These structures demonstrated SPP resonances as narrow as 9.3 nm, with …

Polarized Photocathode R&D At Bnl And Spin Consideration For The Eic Preinjector, Jyoti Biswas, Erdong Wang, Omer Rahman, John Skaritka, Adam Masters, Sylvain Marsillac, Tai-De Li

Electrical & Computer Engineering Faculty Publications

Superlattice GaAs photocathodes are vital for producing polarized electron beams for the Electron-Ion Collider (EIC) at Brookhaven National Laboratory. The electron pre-injector at the EIC requires a 7 nC bunch with at least 85% spin polarization from a GaAs-based superlattice cathode. The doping density of the very surface layer of the cathode needs to be optimized to extract a high bunch charge beam from the high-voltage DC gun. The polarization axis of the emitted beam is longitudinal, and it will be rotated to transverse direction using two Wien filters, each rotating the spin by 45 degrees. In this paper, we …

Time-Marching Quantum Algorithm For Simulation Of Nonlinear Lorenz Dynamics, Efstratios Koukoutsis, George Vahala, Min Soe, Kyriakos Hizanidis, Linda Vahala, Abhay K. Ram

Electrical & Computer Engineering Faculty Publications

Simulating nonlinear classical dynamics on a quantum computer is an inherently challenging task due to the linear operator formulation of quantum mechanics. In this work, we provide a systematic approach to alleviate this difficulty by developing an explicit quantum algorithm that implements the time evolution of a second-order time-discretized version of the Lorenz model. The Lorenz model is a celebrated system of nonlinear ordinary differential equations that has been extensively studied in the contexts of climate science, fluid dynamics, and chaos theory. Our algorithm possesses a recursive structure and requires only a linear number of copies of the initial state …

Streamer Discharge Modeling For Plasma-Assisted Combustion, Stuart Reyes, Shirshak Kumar Dhali

Electrical & Computer Engineering Faculty Publications

Some of the popular and successful atmospheric pressure fuel/air plasma-assisted combustion methods use repetitive ns pulsed discharges and dielectric-barrier discharges. The transient phase in such discharges is dominated by transport under strong space charge from ionization fronts, which is best characterized by the streamer model. The role of the nonthermal plasma in such discharges is to produce radicals, which accelerates the chemical conversion reaction leading to temperature rise and ignition. Therefore, the characterization of the streamer and its energy partitioning is essential to develop a predictive model. We examine the important characteristics of streamers that influence combustion and develop some …

The Effect Of Electrode Geometry On Excited Species Production In Atmospheric Pressure Air-Hydrogen Streamer Discharge, Shirshak Kumar Dhali, Stuart Reyes

Electrical & Computer Engineering Faculty Publications

When a gas is overvolted at or near atmospheric pressure, it results in a streamer discharge formation. Electrode geometries exert significant impact on the electrical breakdown of gases by altering the spatial profile of the electric field. In many applications the efficient generation of radicals is critical and is determined by the characteristics of the streamer discharge. We examine the effect of electrode geometry on the streamer characteristics and the production of radicals. This is performed for three different electrode geometries: plane–plane, pin–plane, and pin–pin. A two-dimensional rotationally symmetric fluid model is used for the streamer discharge simulation in the …