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Measurement Of The Neutron Decay Electron-Antineutrino Angular Correlation By The Acorn Experiment, Alexander Komives, Et Al. Apr 2021

Measurement Of The Neutron Decay Electron-Antineutrino Angular Correlation By The Acorn Experiment, Alexander Komives, Et Al.

Physics & Astronomy Faculty publications

The aCORN experiment measures the neutron-decay electron-antineutrino correlation (a coefficient) using a novel method based on an asymmetry in proton time-of-flight for events where the beta electron and recoil proton are detected in delayed coincidence. We report the data analysis and result from the second run at the NIST Center for Neutron Research, using the high-flux cold neutron beam on the new NG-C neutron guide end position: a=−0.10758±0.00136(stat)±0.00148(sys). This is consistent within uncertainties with the result from the first aCORN run on the NG-6 cold neutron beam. Combining the two aCORN runs, we obtain a=−0.10782±0.00124(stat)±0.00133(sys), which has an overall relative …

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Measurement Report: Firework Impacts On Air Quality In Metro Manila, Philippines, During The 2019 New Year Revelry, Genevieve Rose Lorenzo, Paola Angela Bañaga, Maria Obiminda L. Cambaliza, Melliza Templonuevo Cruz, Mojtaba Azadi Aghdam, Avelino Arellano, Grace Betito, Rachel A. Braun, Andrea F. Corral, Hossein Dadashazar, Eva-Lou Edwards, Edwin Eloranta, Robert Holz, Gabrielle Leung, Lin Ma, Alexander B. Macdonald, Jeffrey S. Reid, James Bernard Simpas, Connor Stahl, Shane Marie Visaga, Armin Sorooshian Apr 2021

Measurement Report: Firework Impacts On Air Quality In Metro Manila, Philippines, During The 2019 New Year Revelry, Genevieve Rose Lorenzo, Paola Angela Bañaga, Maria Obiminda L. Cambaliza, Melliza Templonuevo Cruz, Mojtaba Azadi Aghdam, Avelino Arellano, Grace Betito, Rachel A. Braun, Andrea F. Corral, Hossein Dadashazar, Eva-Lou Edwards, Edwin Eloranta, Robert Holz, Gabrielle Leung, Lin Ma, Alexander B. Macdonald, Jeffrey S. Reid, James Bernard Simpas, Connor Stahl, Shane Marie Visaga, Armin Sorooshian

Physics Faculty Publications

Fireworks degrade air quality, reduce visibility, alter atmospheric chemistry, and cause short-term adverse health effects. However, there have not been any comprehensive physicochemical and optical measurements of fireworks and their associated impacts in a Southeast Asia megacity, where fireworks are a regular part of the culture. Size-resolved particulate matter (PM) measurements were made before, during, and after New Year 2019 at the Manila Observatory in Quezon City, Philippines, as part of the Cloud, Aerosol, and Monsoon Processes Philippines Experiment (CAMP2Ex). A high-spectral-resolution lidar (HSRL) recorded a substantial increase in backscattered signal associated with high aerosol loading ∼440 m above the …

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Gauge Invariant Target Space Entanglement In D-Brane Holography, Sumit R. Das, Anurag Kaushal, Sinong Liu, Gautam Mandal, Sandip P. Trivedi Apr 2021

Gauge Invariant Target Space Entanglement In D-Brane Holography, Sumit R. Das, Anurag Kaushal, Sinong Liu, Gautam Mandal, Sandip P. Trivedi

Physics and Astronomy Faculty Publications

It has been suggested in arXiv:2004.00613 that in Dp-brane holography, entanglement in the target space of the D-brane Yang-Mills theory provides a precise notion of bulk entanglement in the gravity dual. We expand on this discussion by providing a gauge invariant characterization of operator sub-algebras corresponding to such entanglement. This is achieved by finding a projection operator which imposes a constraint characterizing the target space region of interest. By considering probe branes in the Coloumb branch we provide motivation for why the operator sub-algebras we consider are appropriate for describing a class of measurements carried out with low-energy probes in …

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Test Of Lepton-Flavor Universality In B→K∗ℓ+ℓ− Decays At Belle, S. Wehle, I. Adachi, K. Adamczyk, H. Aihara, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, P. Behera, M. Berger, V. Bhardwaj, J. Biswal, A. Bozek, M. Bračko, T. E. Browder, M. Campajola, L. Cao, M. -C. Chang, Milind Purohit, Et. Al. Apr 2021

Test Of Lepton-Flavor Universality In B→K∗ℓ+ℓ− Decays At Belle, S. Wehle, I. Adachi, K. Adamczyk, H. Aihara, D. M. Asner, H. Atmacan, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, P. Behera, M. Berger, V. Bhardwaj, J. Biswal, A. Bozek, M. Bračko, T. E. Browder, M. Campajola, L. Cao, M. -C. Chang, Milind Purohit, Et. Al.

Faculty Publications

We present a measurement of Rk+ , the branching fraction ratio B(B → K+μ+μ−)=B(B → K*e+e−),, for both charged and neutral B mesons. The ratio for the charged case R K* + is the first measurement ever performed. In addition, we report absolute branching fractions for the individual modes in bins of the squared dilepton invariant mass q2. The analysis is based on a data sample of 711 fb−1, containing 772 × 106 BB̅ events, recorded at the ϒ(4S) resonance …

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Sf6+: Stabilizing Transient Ions In Helium Nanodroplets, Simon Albertini, Stefan Bergmeister, Felix Laimer, Paul Martini, Elisabeth Gruber, Fabio Zappa, Milan Ončák, Paul Scheier, Olof E. Echt Apr 2021

Sf6+: Stabilizing Transient Ions In Helium Nanodroplets, Simon Albertini, Stefan Bergmeister, Felix Laimer, Paul Martini, Elisabeth Gruber, Fabio Zappa, Milan Ončák, Paul Scheier, Olof E. Echt

Faculty Publications

There are myriads of ions that are deemed too short-lived to be experimentally accessible. One of them is SF6+. It has never been observed, although not for lack of trying. We demonstrate that long-lived SF6+ can be formed by doping charged helium nanodroplets (HNDs) with sulfur hexafluoride; excess helium is then gently stripped from the doped HNDs by collisions with helium gas. The ion is identified by high-resolution mass spectrometry (resolution m/Dm = 15000), the close agreement between the expected and observed yield of ions that contain minor sulfur isotopes, and collision-induced dissociation …

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Exploring Manifoldlike Causal Sets And Their Dimensions, Santosh Bhandari Apr 2021

Exploring Manifoldlike Causal Sets And Their Dimensions, Santosh Bhandari

Honors Theses

Causal Set Theory is an approach to quantum gravity that tries to replace the continuum spacetime structure of general relativity with the spacetime that has the property of discreteness and causality. From the standpoint of causal set theory, our spacetime is made up of discrete points that are causally related to one another. A causal set is said to be manifoldlike if it can be faithfully embedded in a Lorentzian manifold. In this thesis, some of the fundamental properties of causal sets are discussed. The first chapter is devoted to the historical background of quantum gravity with a discussion of …

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Ion Beam-Treated Space Polymers: Long-Term Stability In Geo-Simulated Environments, Jacob Kleiman, Zelina Iskanderova, Leonid Krishtein, J. R. Dennison, Brian Wood, Anatoly Grigorievsky, Carl Best Apr 2021

Ion Beam-Treated Space Polymers: Long-Term Stability In Geo-Simulated Environments, Jacob Kleiman, Zelina Iskanderova, Leonid Krishtein, J. R. Dennison, Brian Wood, Anatoly Grigorievsky, Carl Best

Journal Articles

As part of a large program conducted between years 2010 and 2018, a number of ion beam surface treatments and proprietary coatings formed on advanced space polymers by direct ion beam deposition were developed at Integrity Testing Laboratory (ITL) Inc, in Canada. Thistechnology allowed producing surfaces with controlled surface resistivity in a wide range of charge dissipation values, with negligibly low additional RF losses and other important functional properties, that allowed using such treated materials and products in modern space antennae, solar arrays and other external applications on spacecrafts in GEO environment. This paper will present an overview of results …

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Measurement Of The Fluctuations In The Number Of Muons In Extensive Air Showers With The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, B. Fick, D. F. Nitz, A. Puyleart, Et. Al. Apr 2021

Measurement Of The Fluctuations In The Number Of Muons In Extensive Air Showers With The Pierre Auger Observatory, A. Aab, P. Abreu, M. Aglietta, J. M. Albury, I. Allekotte, A. Almela, B. Fick, D. F. Nitz, A. Puyleart, Et. Al.

Michigan Tech Publications, Part 1

We present the first measurement of the fluctuations in the number of muons in extensive air showers produced by ultrahigh energy cosmic rays. We find that the measured fluctuations are in good agreement with predictions from air shower simulations. This observation provides new insights into the origin of the previously reported deficit of muons in air shower simulations and constrains models of hadronic interactions at ultrahigh energies. Our measurement is compatible with the muon deficit originating from small deviations in the predictions from hadronic interaction models of particle production that accumulate as the showers develop.

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A Search For New Physics In B(S) To Mu+Mu- Decays Using Multivariate Data Analysis, And Development Of Particle Detection Technology With Silicon Pixel Detectors, Aidan Grummer Apr 2021

A Search For New Physics In B(S) To Mu+Mu- Decays Using Multivariate Data Analysis, And Development Of Particle Detection Technology With Silicon Pixel Detectors, Aidan Grummer

Physics & Astronomy ETDs

A suite of linked research projects is undertaken, combining a search for phenomena beyond the Standard Model of particle physics, development of new instruments for greater precision in detecting fundamental particles, and tracking and understanding the effect upon the detectors of the radiation that is an indelible element of their operating environment. Data recorded by the ATLAS Detector at CERN are employed in a search for evidence of undiscovered particles contributing to the rate of decays of B0 and B0s mesons to dimuon final states. New applications of machine learning techniques are implemented to separate this signal …

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Improved Bounds On Lorentz Symmetry Violation From High-Energy Astrophysical Sources, Brett David Altschul Apr 2021

Improved Bounds On Lorentz Symmetry Violation From High-Energy Astrophysical Sources, Brett David Altschul

Faculty Publications

Observations of the synchrotron and inverse Compton emissions from ultrarelativistic electrons in astrophysical sources can reveal a great deal about the energy–momentum relations of those electrons. They can thus be used to place bounds on the possibility of Lorentz violation in the electron sector. Recent 𝛾 -ray telescope data allow the Lorentz-violating electron 𝑐𝜈𝜇 parameters to be constrained extremely well, so that all bounds are at the level of 7×10−16 or better.

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Pinta: The Ugmrt Data Processing Pipeline For The Indian Pulsar Timing Array, Abhimanyu Susobhanan, Yogesh Maan, Bhal Chandra Joshi, T. Prabu, Shantanu Desai, K. Nobleson, Sai Chaitanya Susarla, Raghav Girgaonkar, Lankeswar Dey, Suryarao Bethapudi Apr 2021

Pinta: The Ugmrt Data Processing Pipeline For The Indian Pulsar Timing Array, Abhimanyu Susobhanan, Yogesh Maan, Bhal Chandra Joshi, T. Prabu, Shantanu Desai, K. Nobleson, Sai Chaitanya Susarla, Raghav Girgaonkar, Lankeswar Dey, Suryarao Bethapudi

Physics & Astronomy Faculty Publications

We introduce pinta, a pipeline for reducing the upgraded Giant Metre-wave Radio Telescope (uGMRT) raw pulsar timing data, developed for the Indian Pulsar Timing Array experiment. We provide a detailed description of the workflow and usage of pinta, as well as its computational performance and RFI mitigation characteristics. We also discuss a novel and independent determination of the relative time offsets between the different back-end modes of uGMRT and the interpretation of the uGMRT observation frequency settings and their agreement with results obtained from engineering tests. Further, we demonstrate the capability of pinta to generate data products which can produce …

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Probing The Galactic Agb Population Through Infrared And Sio Maser Emission, Megan O. Lewis Apr 2021

Probing The Galactic Agb Population Through Infrared And Sio Maser Emission, Megan O. Lewis

Physics & Astronomy ETDs

Stars on the Asymptotic Giant Branch (AGB) are of low to intermediate mass and have reached the end stages of stellar evolution. The mass-loss that stars undergo at this phase enshrouds the central star in a circumstellar envelope (CSE) that redistributes most of the stellar light into the infrared (IR) regime of the spectrum. In the CSEs of oxygen-rich AGB stars molecules including SiO form, and under certain conditions maser emission from SiO can make AGB stars bright beacons at radio frequencies (e.g., 43 and 86 GHz). SiO masers are ideal observational probes of AGB sources, providing data on their …

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Implications Of The Quantum Dna Model For Information Sciences, F. Matthew Mihelic Apr 2021

Implications Of The Quantum Dna Model For Information Sciences, F. Matthew Mihelic

Faculty Publications

The DNA molecule can be modeled as a quantum logic processor, and this model has been supported by pilot research that experimentally demonstrated non-local communication between cells in separated cell cultures. This modeling and pilot research have important implications for information sciences, providing a potential architecture for quantum computing that operates at room temperature and is scalable to millions of qubits, and including the potential for an entanglement communication system based upon the quantum DNA architecture. Such a system could be used to provide non-local quantum key distribution that could not be blocked by any shielding or water depth, would …

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Pint: A Modern Software Package For Pulsar Timing, Jing Luo, S. M. Ransom, Paul B. Demorest, P. S. Ray, Anne M. Archibald, M. Kerr, Ross J. Jennings, Matteo Bachetti, Rutger Van Haasteren, Fredrick A. Jenet Apr 2021

Pint: A Modern Software Package For Pulsar Timing, Jing Luo, S. M. Ransom, Paul B. Demorest, P. S. Ray, Anne M. Archibald, M. Kerr, Ross J. Jennings, Matteo Bachetti, Rutger Van Haasteren, Fredrick A. Jenet

Physics & Astronomy Faculty Publications

Over the past few decades, the measurement precision of some pulsar timing experiments has advanced from ~10 μs to ~10 ns, revealing many subtle phenomena. Such high precision demands both careful data handling and sophisticated timing models to avoid systematic error. To achieve these goals, we present PINT (PINT Is Not Tempo3), a high-precision Python pulsar timing data analysis package, which is hosted on GitHub and available on the Python Package Index (PyPI) as pint-pulsar. PINT is well tested, validated, object oriented, and modular, enabling interactive data analysis and providing an extensible and flexible development platform for timing applications. …

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Investigating The Use Of Ultraviolet Light Emitting Diodes (Uv-Leds) For The Inactivation Of Bacteria In Powdered Food Ingredients, Laura Nyhan, Milosz Przyjalgowski, Liam O'Faolain, Máire Begley, Michael Callanan Apr 2021

Investigating The Use Of Ultraviolet Light Emitting Diodes (Uv-Leds) For The Inactivation Of Bacteria In Powdered Food Ingredients, Laura Nyhan, Milosz Przyjalgowski, Liam O'Faolain, Máire Begley, Michael Callanan

Cappa Publications

The addition of contaminated powdered spices and seasonings to finished products which do not undergo further processing represents a significant concern for food manufacturers. To reduce the incidence of bacterial contamination, seasoning ingredients should be subjected to a decontamination process. Ultraviolet light emitting diodes (UV-LEDs) have been suggested as an alternative to UV lamps for reducing the microbial load of foods, due to their increasing efficiency, robustness and decreasing cost. In this study, we investigated the efficacy of UV-LED devices for the inactivation of four bacteria (Listeria monocytogenes, Escherichia coli, Bacillus subtilis and Salmonella Typhimurium) on a plastic surface and …

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Measurement Report: Comparison Of Wintertime Individual Particles At Ground Level And Above The Mixed Layer In Urban Beijing, Wenhua Wang, Longyi Shao, Claudio Mazzoleni, Yaowei Li, Simone Kotthaus, Sue Grimmond, Janarjan Bhandari, Jiaoping Xing, Xiaolei Feng, Mengyuan Zhang, Zongbo Shi Apr 2021

Measurement Report: Comparison Of Wintertime Individual Particles At Ground Level And Above The Mixed Layer In Urban Beijing, Wenhua Wang, Longyi Shao, Claudio Mazzoleni, Yaowei Li, Simone Kotthaus, Sue Grimmond, Janarjan Bhandari, Jiaoping Xing, Xiaolei Feng, Mengyuan Zhang, Zongbo Shi

Michigan Tech Publications, Part 1

Beijing has been suffering from frequent severe air pollution events, with concentrations affected significantly by the mixed-layer height. Major efforts have been made to study the physico-chemical properties, compositions, and sources of aerosol particles at ground level. However, little is known about the morphology, elemental composition, and mixing state of aerosol particles above the mixed layer. In this work, we collected individual aerosol particles simultaneously at ground level (2 m above ground) and above the mixed layer in urban Beijing (within the Atmospheric Pollution and Human Health in a Chinese Megacity, APHH-Beijing, 2016 winter campaign). The particles were analyzed offline …

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Securing Pint Glasses On Serving Trays With Magnetic Attachments, Jayden Commendatore Apr 2021

Securing Pint Glasses On Serving Trays With Magnetic Attachments, Jayden Commendatore

Senior Theses

It is extremely common for servers in the restaurant industry to have pint glasses slip off their serving tray, wasting both time and money for the restaurant. I have designed a sleeve attachment that will clip on to the bottom of a pint glass. The metal sleeve attachment will be attracted to a magnet placed into the serving tray. This increases the normal force of the pint glass, resulting in an increase in the friction force between the tray and sleeve attachment, and helping secure the glass to the tray. In order to optimize the design, the value of the …

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Design Of Smart Trashcan, Haoran Song Apr 2021

Design Of Smart Trashcan, Haoran Song

Senior Theses

A smart trashcan has been designed which can bring convenience to people for throwing their garbage away during the COVID-19 pandemic. A prototype is made from cardboard to demonstrate its function. This trashcan can sense people who are coming and leaving, and it can open and close automatically. The trashcan is powered by solar energy. A solar panel is mounted on top of the trashcan supporter. This design is specifically for use in China.

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The Effect Of Environmental Context Upon Visual Distance Perception, Jessica M. Dukes Apr 2021

The Effect Of Environmental Context Upon Visual Distance Perception, Jessica M. Dukes

Masters Theses & Specialist Projects

The ability of 16 younger adults to visually perceive distances in depth was evaluated within three environmental contexts (indoors in the dark, indoors in the light, and outdoors). The observers' task was to bisect an 8m distance interval in all contexts using both monocular and binocular vision. In the outdoor environment (a natural grassy field), the observers' judgments indicated perceptual compression of farther distances similar to that obtained in many previous studies. In the indoor lighted environment (a 10.2 x 9.6m laboratory room), the observers' judgments were consistent with perceptual expansion of farther distances. Finally, there was a beneficial effect …

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Combination Of Cluster Number Counts And Two-Point Correlations: Validation On Mock Dark Energy Survey, Chun-Hao To, Elisabeth Krause, Eduardo Rozo, Heidi Wu, Daniel Gruen, Joseph Derose, Eli Rykoff, Risa H. Wechsler, Matthew Becker, Matteo Costanzi, Tim Eifler, Maria Elidaiana Da Silva Pereira, Nickolas Kokron Apr 2021

Combination Of Cluster Number Counts And Two-Point Correlations: Validation On Mock Dark Energy Survey, Chun-Hao To, Elisabeth Krause, Eduardo Rozo, Heidi Wu, Daniel Gruen, Joseph Derose, Eli Rykoff, Risa H. Wechsler, Matthew Becker, Matteo Costanzi, Tim Eifler, Maria Elidaiana Da Silva Pereira, Nickolas Kokron

Physics Faculty Publications and Presentations

We present a method of combining cluster abundances and large-scale two-point correlations, namely galaxy clustering, galaxy–cluster cross-correlations, cluster autocorrelations, and cluster lensing. This data vector yields comparable cosmological constraints to traditional analyses that rely on small-scale cluster lensing for mass calibration. We use cosmological survey simulations designed to resemble the Dark Energy Survey Year 1 (DES-Y1) data to validate the analytical covariance matrix and the parameter inferences. The posterior distribution from the analysis of simulations is statistically consistent with the absence of systematic biases detectable at the precision of the DES-Y1 experiment. We compare the χ2 values in simulations …

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On The Halo-Mass And Radial Scale Dependence Of The Lensing Is Low Effect, J. U. Lange, A. Leauthaud, S. Singh, H. Guo, R. Zhou, Tristan L. Smith, F.-Y. Cyr-Racine Apr 2021

On The Halo-Mass And Radial Scale Dependence Of The Lensing Is Low Effect, J. U. Lange, A. Leauthaud, S. Singh, H. Guo, R. Zhou, Tristan L. Smith, F.-Y. Cyr-Racine

Physics & Astronomy Faculty Works

The canonical Lambda cold dark matter (ΛCDM) cosmological model makes precise predictions for the clustering and lensing properties of galaxies. It has been shown that the lensing amplitude of galaxies in the Baryon Oscillation Spectroscopic Survey (BOSS) is lower than expected given their clustering properties. We present new measurements and modelling of galaxies in the BOSS LOWZ sample. We focus on the radial and stellar mass dependence of the lensing amplitude mismatch. We find an amplitude mismatch of around 35 per cent when assuming ΛCDM with Planck Cosmological Microwave Background (CMB) constraints. This offset is independent of halo mass and …

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Dipole Emission Characteristics Near A Topological Insulator Sphere Coated With A Metallic Nanoshell, Huai-Yi Xie, Railing Chang, P. T. Leung Apr 2021

Dipole Emission Characteristics Near A Topological Insulator Sphere Coated With A Metallic Nanoshell, Huai-Yi Xie, Railing Chang, P. T. Leung

Physics Faculty Publications and Presentations

Topological insulators (TI) are quantum states of (2D/3D) matter with an insulating interior but conducting edge/surface states, with these boundary conducting states being protected topologically by time-reversal symmetry. Composite materials of heavy atoms such as Bi2Te3 can be fabricated to show TI properties due to the strong intrinsic spin-orbit coupling of the electrons in these materials. Among the so many intriguing physical properties of these materials, their topological magneto-electric (TME) response is unique and has been studied intensively in the literature, leading to intriguing optical effects such as Faraday and Kerr rotations of incident polarized beams at …

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Expanding The Frontiers Of Supernova Cosmology In Preparation For Next Generation Telescopes, Justin Roberts-Pierel Apr 2021

Expanding The Frontiers Of Supernova Cosmology In Preparation For Next Generation Telescopes, Justin Roberts-Pierel

Theses and Dissertations

Supernova (SN) research has been the source of many astronomical discoveries over the past several decades, most prominently the accelerated expansion of the universe by so-called “dark energy” in 1998. Next generation surveys like the Vera C. Rubin Observatory and the Nancy G. Roman Space Telescope, in large part through traditional luminosity distance measurements with Type Ia supernovae (SNe Ia), are set to reveal more about the nature of dark energy this decade than at any time in history. The enormous SN Ia samples from Roman and Rubin mean cosmological inferences will no longer be limited by statistical uncertainties, …

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Measurement Of N* Cross-Sections From Single-Pion Electroproduction At Low Q^2, Nicholas Scoville Tyler Apr 2021

Measurement Of N* Cross-Sections From Single-Pion Electroproduction At Low Q^2, Nicholas Scoville Tyler

Theses and Dissertations

Measurements of nucleon electroexcitation resonance cross-sections give unique insight into the dynamics of the strong interaction and our knowledge of Quantum Chromodynamics (QCD). The analysis of exclusive electroproduction data is an important tool in understanding the structure of the nucleon and its excited states. Exclusive channels give a clear way to extract the desired resonant contributions from non-resonant contributions. A gap in the helicity amplitudes extracted from single-pion cross-section data exists for virtual photon momentum transfers ($Q^2$) in the range of $1-2~\mathrm{GeV}^{2}$. Using data collected by the CEBAF Large Acceptance Spectrometer (CLAS) detector with a beam energy of $4.8~\mathrm{GeV}$, the …

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Zn Acceptors In Β-Ga2O3 Crystals, Timothy D. Gustafson, J. Jesenovec, Christopher A. Lenyk, Nancy C. Giles, J. S. Mccloy, M. Mccluskey, Larry E. Halliburton Apr 2021

Zn Acceptors In Β-Ga2O3 Crystals, Timothy D. Gustafson, J. Jesenovec, Christopher A. Lenyk, Nancy C. Giles, J. S. Mccloy, M. Mccluskey, Larry E. Halliburton

Faculty Publications

Electron paramagnetic resonance (EPR) is used to identify and characterize neutral zinc acceptors in Zn-doped β-Ga2O3 crystals. Two EPR spectra are observed at low temperatures, one from Zn ions at tetrahedral Ga(1) sites (the Zn0Ga1 acceptor) and one from Zn ions at octahedral Ga(2) sites (the Zn0Ga2 acceptor). These Zn acceptors are small polarons, with the unpaired spin localized in each case on a threefold coordinated oxygen O(I) ion adjacent to the Zn ion. Resolved hyperfine interactions with neighboring 69Ga and 71Ga nuclei allow the EPR spectra from the two acceptors …

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Measuring Strain-Mediated Magnetoelectric Effects In Magnetically Self-Assembled Multiferroic Janus Nanofiber Chains: A Quest For New Techniques To Study Multiferroic Nanomaterials, Bryan Lucas Chávez Apr 2021

Measuring Strain-Mediated Magnetoelectric Effects In Magnetically Self-Assembled Multiferroic Janus Nanofiber Chains: A Quest For New Techniques To Study Multiferroic Nanomaterials, Bryan Lucas Chávez

Theses and Dissertations

Bi-phasic composite multiferroics couple piezoelectric and magnetostrictive proper- ties via an interfacial strain, allowing for control of their magnetic properties with electric fields and vice versa. Nanofibers have a larger area-to-volume ratio than thin films and are not affected by substrate clamping, leading to a predicted magnetoelec- tric coupling an order of magnitude higher than those found in thin-film multiferroics. Nanofibers have potential applications in photonics, nanoelectronics, biosensing, and optoelectronics. This work focuses on measuring magnetoelectric effects in electro- spun nanofibers made of barium titanate (BaTiO3) and cobalt ferrite (CoFe2O4). To transform the disordered …

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Laser Cooling Of Antihydrogen Atoms, C. J. Baker, W. Bertsche, A. Capra, C. Carruth, C. L. Cesar, M. Charlton, A. Christensen, R. Collister, A. Cridland Mathad, S. Eriksson, A. Evans, N. Evetts, J. Fajans, T. Friesen, M. C. Fujiwara, D. R. Gill, P. Grandemange, P. Granum, J. S. Hangst, W. N. Hardy, M. E. Hayden, D. Hodgkinson, E. D. Hunter, C. A. Isaac, M. A. Johnson, J. M. Jones, S. A. Jones, S. Jonsell, A. Khramov, P. Knapp, L. Kurchaninov, N. Madsen, D. Maxwell, J. T. K. Mckenna, S. Menary, J. M. Michan, T. Momose, P. S. Mullan, K. Olchanski, A. Olin, J. Peszka, A. Powell, P. Pusa, C. O. Rasmussen, F. Robicheaux, R. L. Sacramento, M. Sameed, E. Sarid, D. M. Silveira, D, M. Starko, C. So, G. Stutter, Timothy Tharp, A. Thibeault, R. I. Thompson, D. P. Van Der Werf, J. S. Wurtele Apr 2021

Laser Cooling Of Antihydrogen Atoms, C. J. Baker, W. Bertsche, A. Capra, C. Carruth, C. L. Cesar, M. Charlton, A. Christensen, R. Collister, A. Cridland Mathad, S. Eriksson, A. Evans, N. Evetts, J. Fajans, T. Friesen, M. C. Fujiwara, D. R. Gill, P. Grandemange, P. Granum, J. S. Hangst, W. N. Hardy, M. E. Hayden, D. Hodgkinson, E. D. Hunter, C. A. Isaac, M. A. Johnson, J. M. Jones, S. A. Jones, S. Jonsell, A. Khramov, P. Knapp, L. Kurchaninov, N. Madsen, D. Maxwell, J. T. K. Mckenna, S. Menary, J. M. Michan, T. Momose, P. S. Mullan, K. Olchanski, A. Olin, J. Peszka, A. Powell, P. Pusa, C. O. Rasmussen, F. Robicheaux, R. L. Sacramento, M. Sameed, E. Sarid, D. M. Silveira, D, M. Starko, C. So, G. Stutter, Timothy Tharp, A. Thibeault, R. I. Thompson, D. P. Van Der Werf, J. S. Wurtele

Physics Faculty Research and Publications

The photon—the quantum excitation of the electromagnetic field—is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6,7,8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we …

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Electrostatic Design And Characterization Of A 200 Kev Photogun And Wien Spin Rotator, Gabriel G. Palacios Serrano Apr 2021

Electrostatic Design And Characterization Of A 200 Kev Photogun And Wien Spin Rotator, Gabriel G. Palacios Serrano

Electrical & Computer Engineering Theses & Dissertations

High-energy nuclear physics experiments at the Jefferson Lab Continuous Electron Beam Accelerator Facility (CEBAF) require high spin-polarization electron beams produced from strained super-lattice GaAs photocathodes activated to negative electron affinity in a high voltage photogun operating at 130 kV dc. A pair of Wien filter spin rotators in the injector provides precise control of the electron beam polarization at the end station target. An upgrade of the CEBAF injector to better support the upcoming Moller experiment requires increasing the electron beam energy to 200 keV, resulting in better transmission through injector apertures and improved photocathode lifetime. In addition, the energy …

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Spectator Proton Detection And Reconstruction In Deep Inelastic D(E,EpS) Scattering, David Payette Apr 2021

Spectator Proton Detection And Reconstruction In Deep Inelastic D(E,EpS) Scattering, David Payette

Physics Theses & Dissertations

A Radial Time Projection Chamber (RTPC) was designed and installed in Jefferson Lab's Hall B as part of the BONuS12 (Barely Off-shell Nucleon Structure) experiment. The goal of BONuS12 is to accurately measure the structure function of the neutron by scattering 11 GeV electrons and detecting them with the CLAS12 spectrometer. Deuterium gas was used as an effective neutron target, and the new RTPC was used to detect low- momentum spectator protons. Protons follow a curved path in the 5 Tesla solenoid that is part of CLAS12, ionizing the He-CO2 gas in an annular drift region surrounding the target. These …

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Exploring Qcd Factorization At Moderate Energy Scales, Eric Alan Moffat Apr 2021

Exploring Qcd Factorization At Moderate Energy Scales, Eric Alan Moffat

Physics Theses & Dissertations

Asymptotic freedom in QCD facilitates the use of partonic degrees of freedom over short distances, but physical processes are sensitive to a wide range of scales. Thus, it is necessary in QCD calculations to utilize a factorization scheme to separate a process into perturbative and non-perturbative factors. This separation relies on an assumption that one energy scale is infinitely larger than the other scales involved in the process. However, much experimental research in areas such as nucleon structure and quark-hadron duality occur at more moderate energy scales where that basic assumption may not be true but perturbative calculations should still …

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