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2024

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Full-Text Articles in Engineering Physics

Igniting Passion:​ A Detailed Journey Through Rocketry Course Activities, Krish M. Patel, Hannah Caycedo, Joshua Gage, Josi Maness, Kevin Park, Mufeng Shen Apr 2024

Igniting Passion:​ A Detailed Journey Through Rocketry Course Activities, Krish M. Patel, Hannah Caycedo, Joshua Gage, Josi Maness, Kevin Park, Mufeng Shen

SACAD: Scholarly Activities

This course is a semester-long adventure in rocketry, led by Dr. Paul Adams. It covers everything about building and flying rockets, starting from the basics to more advanced rocketry. Students learn how to build rockets and use equipment used I payload systems like and altimeter and a GPS. We also learned about the importance of safety involved with building and launching rockets.


Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford Apr 2024

Low Cost Magnetometer Calibration And Distributed Simultaneous Multipoint Ionospheric Measurements From A Sounding Rocket Platform, Joshua W. Milford

Doctoral Dissertations and Master's Theses

Low-cost and low-size-weight-and-power (SWaP) magnetometers can provide greater accessibility for distributed simultaneous measurements in the ionosphere, either onboard sounding rockets or on CubeSats. The Space and Atmospheric Instrumentation Laboratory (SAIL) at Embry-Riddle Aeronautical University has launched a multitude of sounding rockets in recent history: one night-time mid-latitude rocket from Wallops Flight Facility in August 2022 and three mid-latitude rockets from White Sands Missile Range during the October 2023 annular solar eclipse. All rockets had a comprehensive suite of instruments for electrodynamics and neutral dynamics measurements. Among this suite was one science-grade three-axis fluxgate magnetometer (Billingsley TFM65VQS / TFM100G2) and up …


Effect Of Fabrication Parameters On The Ferroelectricity Of Hafnium Zirconium Oxide Films: A Statistical Study, Guillermo A. Salcedo, Ahmad E. Islam, Elizabeth Reichley, Michael Dietz, Christine M. Schubert Kabban, Kevin D. Leedy, Tyson C. Back, Weison Wang, Andrew Green, Timothy S. Wolfe, James M. Sattler Mar 2024

Effect Of Fabrication Parameters On The Ferroelectricity Of Hafnium Zirconium Oxide Films: A Statistical Study, Guillermo A. Salcedo, Ahmad E. Islam, Elizabeth Reichley, Michael Dietz, Christine M. Schubert Kabban, Kevin D. Leedy, Tyson C. Back, Weison Wang, Andrew Green, Timothy S. Wolfe, James M. Sattler

Faculty Publications

Ferroelectricity in hafnium zirconium oxide (Hf1−xZrxO2) and the factors that impact it have been a popular research topic since its discovery in 2011. Although the general trends are known, the interactions between fabrication parameters and their effect on the ferroelectricity of Hf1−xZrxO2 require further investigation. In this paper, we present a statistical study and a model that relates Zr concentration (x), film thickness (tf), and annealing temperature (Ta) with the remanent polarization (Pr) in tungsten (W)-capped Hf1−xZrxO2. …


Coomassie Brilliant Blue Dye As A Method For Analyzing Fracture Markings In Bone, Abigail Hoffmeister, David Harutunyan, Matthew Aizawa, Everett Baker, Brandon Mendoza, Chase Freeman, Siran Iskanian Mar 2024

Coomassie Brilliant Blue Dye As A Method For Analyzing Fracture Markings In Bone, Abigail Hoffmeister, David Harutunyan, Matthew Aizawa, Everett Baker, Brandon Mendoza, Chase Freeman, Siran Iskanian

Seaver College Research And Scholarly Achievement Symposium

Coomassie Brilliant Blue Dye is a dye commonly used to stain proteins. Because of its ability to adhere to proteins, this research has focused on perfecting a method of dyeing a fractured flat bone in order to most accurately observe and analyze fracture markings within the trabecular layer. Stereoscopic microscopy was the chosen technique of analysis for this research because of its proven effectiveness in glass and ceramic fractography to observe varying depths. In order to most effectively apply stereoscopic microscopy to this research, the following variables were manipulated to maximize color contrast in the trabecular layer in order to …


Feasibility Of A Zero-Length Spring Gravimeter For Use In Portal Monitoring, Matthew C. Stone Mar 2024

Feasibility Of A Zero-Length Spring Gravimeter For Use In Portal Monitoring, Matthew C. Stone

Theses and Dissertations

In recent years, gravimeters have become sensitive enough to theoretically measure masses of interest at distances relevant for portal monitoring. Characterizing the re[1]sponse of the gravimeter to close range masses across a large solid angle is necessary before attempting to demonstrate a portal-monitoring-like measurement due to this mission being outside the scope of typical gravimeter operations. The characterization of the gravimeter focused on three primary topics. For the position-dependent bias, it is found that the models used overestimate the expected observed gravity when the test mass is closest to the gravimeter in four out of seventeen experiments and under[1]estimate the …


The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin Feb 2024

The Behavior Of ½⟨111⟩ Screw Dislocations In W–Mo Alloys Analyzed Through Atomistic Simulations, Lucas A. Heaton, Kevin Chu, Adib J. Samin

Faculty Publications

Analyzing plastic flow in refractory alloys is relevant to many different commercial and technological applications. In this study, screw dislocation statics and dynamics were studied for various compositions of the body-centered cubic binary alloy tungsten–molybdenum (W–Mo). The core structure did not appear to change for different alloy compositions, consistent with the literature. The pure tungsten and pure molybdenum samples had the lowest plastic flow, while the highest dislocation velocities were observed for equiatomic, W0.5Mo0.5 alloys. In general, dislocation velocities were found to largely align with a well-established dislocation mobility phenomenological model supporting two discrete dislocation mobility regimes, …


Search For Decaying Dark Matter In The Virgo Cluster Of Galaxies With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, J. Cotzomi, S. Coutiño De León, D. Depaoli, R. Diaz Hernandez, M. A. Duvernois, M. Durocher, N. Fraija, J. A. Garcia-Gonzalez, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez-Cadena, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, V. Joshi, S. Kaufmann, H. Leon Vargas, J. T. Linneman, A. L. Longinotti, G. Luis-Raya, K. Malone, J. Martinez-Castro, J. A. Matthews, P. Mieanda-Romagnoli, J. A. Morales-Soto, M. Mostafa, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, M. Schneider, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, L. Villasenor, Xiaojie Wang, I. J. Watson, S. Yun-Carcamo Feb 2024

Search For Decaying Dark Matter In The Virgo Cluster Of Galaxies With Hawc, A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, J. Cotzomi, S. Coutiño De León, D. Depaoli, R. Diaz Hernandez, M. A. Duvernois, M. Durocher, N. Fraija, J. A. Garcia-Gonzalez, M. M. Gonzalez, J. A. Goodman, J. P. Harding, S. Hernandez-Cadena, I. Herzog, D. Huang, F. Hueyotl-Zahuantitla, V. Joshi, S. Kaufmann, H. Leon Vargas, J. T. Linneman, A. L. Longinotti, G. Luis-Raya, K. Malone, J. Martinez-Castro, J. A. Matthews, P. Mieanda-Romagnoli, J. A. Morales-Soto, M. Mostafa, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, N. Omodei, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, M. Schneider, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, L. Villasenor, Xiaojie Wang, I. J. Watson, S. Yun-Carcamo

Physics Faculty Research & Creative Works

The decay or annihilation of dark matter particles may produce a steady flux of very-high-energy gamma rays detectable above the diffuse background. Nearby clusters of galaxies provide excellent targets to search for the signatures of particle dark matter interactions. In particular, the Virgo cluster spans several degrees across the sky and can be efficiently probed with a wide field-of-view instrument. The High Altitude Water Cherenkov (HAWC) observatory, due to its wide field of view and sensitivity to gamma rays at an energy scale of 300 GeV-100 TeV is well-suited for this search. Using 2141 days of data, we search for …


Weak-Strong Beam-Beam Simulation With Crab Cavity Noises For The Hadron Storage Ring Of The Electron-Ion Collider, Y. Luo, B. Gamage, C. Montag, D. Marx, D. Xu, F. Willeke, H. Huang, H. Lovelace Iii, J. Berg, M. Blaskiewicz, S. Peggs, T. Satogata, V. Ptitsyn, V. Morozov, Y. Hao Jan 2024

Weak-Strong Beam-Beam Simulation With Crab Cavity Noises For The Hadron Storage Ring Of The Electron-Ion Collider, Y. Luo, B. Gamage, C. Montag, D. Marx, D. Xu, F. Willeke, H. Huang, H. Lovelace Iii, J. Berg, M. Blaskiewicz, S. Peggs, T. Satogata, V. Ptitsyn, V. Morozov, Y. Hao

Mathematics & Statistics Faculty Publications

The Electron Ion Collider (EIC), to be constructed at Brookhaven National Laboratory, will collide polarized high-energy electron beams with hadron beams, achieving luminosities of up to 1 X 1034cm−2s−1 in the center-mass energy range of 20-140 GeV. Crab cavities are employed to compensate for the geometric luminosity loss caused by a large crossing angle of 25 mrad in the interaction region. The phase noise in crab cavities will induce a significant emittance growth for the hadron beams in the Hadron Storage Ring (HSR). Various models have been utilized to study the effects of crab cavity …


Charged Track Reconstruction With Artificial Intelligence For Clas12, Gagik Gavalian, Polykarpos Thomadakis, Angelos Angelopoulos, Nikos Chrisochoides Jan 2024

Charged Track Reconstruction With Artificial Intelligence For Clas12, Gagik Gavalian, Polykarpos Thomadakis, Angelos Angelopoulos, Nikos Chrisochoides

Computer Science Faculty Publications

In this paper, we present the results of charged particle track reconstruction in CLAS12 using artificial intelligence. In our approach, we use neural networks working together to identify tracks based on the raw signals in the Drift Chambers. A Convolutional Auto-Encoder is used to de-noise raw data by removing the hits that do not satisfy the patterns for tracks, and second Multi-Layer Perceptron is used to identify tracks from combinations of clusters in the drift chambers. Our method increases the tracking efficiency by 50% for multi-particle final states already conducted experiments. The de-noising results indicate that future experiments can run …


Computationally Modeling The Human-Structure Interaction Response Of An Occupied Cantilevered Structure, Brennan Smith Jan 2024

Computationally Modeling The Human-Structure Interaction Response Of An Occupied Cantilevered Structure, Brennan Smith

Honors Theses

There is a limited understanding of the impact that passive human occupants have on a dynamic structural system, referred to as Human-Structure Interaction (HSI). Cantilevers are naturally prone to excessive vibrations due to their long unsupported spans, and cantilevered structures such as those commonly found in the seating area of a stadium facility or concert hall are designed to support a high density of occupancy.

This study determined that HSI in cantilevered structures can be modeled using a simple two-degree-of-freedom system. The results of the model were validated by data that was collected on a small-scale laboratory structure intentionally designed …


Disaggregating Longer-Term Trends From Seasonal Variations In Measured Pv System Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon Jan 2024

Disaggregating Longer-Term Trends From Seasonal Variations In Measured Pv System Performance, Chibuisi Chinasaokwu Okorieimoh, Brian Norton, Michael Conlon

Articles

Photovoltaic (PV) systems are widely adopted for renewable energy generation, but their performance is influenced by complex interactions between longer-term trends and seasonal variations. This study aims to remove these factors and provide valuable insights for optimising PV system operation. We employ comprehensive datasets of measured PV system performance over five years, focusing on identifying the distinct contributions of longer-term trends and seasonal effects. To achieve this, we develop a novel analytical framework that combines time series and statistical analytical techniques. By applying this framework to the extensive performance data, we successfully break down the overall PV system output into …


Processing, Stability, And High-Temperature Properties Of Doped Lacro3-Based Refractory Ceramics And Composites For Harsh Environments Sensing Applications, Javier A. Mena Jan 2024

Processing, Stability, And High-Temperature Properties Of Doped Lacro3-Based Refractory Ceramics And Composites For Harsh Environments Sensing Applications, Javier A. Mena

Graduate Theses, Dissertations, and Problem Reports (ETD)

In order to test and monitor the operational stability and conditions of various energy, transportation, and manufacturing systems and their components, accurate sensors capable of operating at temperatures over 1000 °C in various environments for long durations are required. In addition, many of these harsh environmental systems do not permit sensors to be directly inserted into the environment, so the sensors need to be embedded into the surrounding support or thermal protective materials. Some technological and industrial applications that require the use of harsh environment conditions sensing include nuclear and chemical reactors, jet engines, heavyduty gas turbines, rotating bearings in …


Progress In Physics: Twentieth Year Of Publication, Florentin Smarandache, Andreas Ries, Pierre Millette, Ebenezer Chifu Jan 2024

Progress In Physics: Twentieth Year Of Publication, Florentin Smarandache, Andreas Ries, Pierre Millette, Ebenezer Chifu

Branch Mathematics and Statistics Faculty and Staff Publications

The journal Progress in Physics was created in January 2005 on behalf of many influential scientists with whom we were in correspondence. The main reason was that publications in other journals were allowed only if the submitter was affiliated with a scientific institution or research organization. Given this situation, many working scientists finding themselves partially employed or unemployed, such as in between research grants, find themselves unable to publish their research results. Even e-print archives such as Cornell’s arXiv required scientific affiliation and still follow this policy.


Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov Jan 2024

Photoluminescence Of Beryllium-Related Defects In Gallium Nitride, Mykhailo Vorobiov, Mykhailo Vorobiov

Theses and Dissertations

This study explores the potential of beryllium (Be) as an alternative dopant to magnesium (Mg) for achieving higher hole concentrations in gallium nitride (GaN). Despite Mg prominence as an acceptor in optoelectronic and high-power devices, its deep acceptor level at 0.22 eV above the valence band limits its effectiveness. By examining Be, this research aims to pave the way to overcoming these limitations and extend the findings to aluminum nitride and aluminum gallium nitride (AlGaN) alloy. Key contributions of this work include. i)Identification of three Be-related luminescence bands in GaN through photoluminescence spectroscopy, improving the understanding needed for further material …


Gas Evolution Of A Nickel-Zinc Cell, Niklas Landgraf Jan 2024

Gas Evolution Of A Nickel-Zinc Cell, Niklas Landgraf

Graduate Theses/Dissertations

Batteries are a foundational technology in some of the industries most essential to humanity. Often, their advancement to achieve better performance impacts human lives positively. There are a wide variety of battery chemistries that have been utilized, and the differences in their properties have caused them to be used in many distinct niche applications. Nickel-Zinc (NiZn) batteries are desirable because of their recyclable materials, high cell voltage, and high cycle-life. However, it experiences undesirable shape-change of its electrode materials and gas production due to the electrolysis of the aqueous electrolyte. These can lead to a decrease in capacity over many …


Magneto-Thermal Limitations In Superconducting Cavities At High Radio-Frequency Fields, I. Parajuli, G. Ciovati, A. Gurevich Jan 2024

Magneto-Thermal Limitations In Superconducting Cavities At High Radio-Frequency Fields, I. Parajuli, G. Ciovati, A. Gurevich

Physics Faculty Publications

The performance of superconducting radio-frequency Nb cavities at high radio-frequency (rf) fields in the absence of field emission can be limited by either a sharp decrease of the quality factor Q0(Bp) above peak surface magnetic fields Bp ∼100 mT or by a quench. We have measured Q0(Bp) at 2 K of several 1.3 GHz single-cell Nb cavities with different grain sizes, and with different ambient magnetic fields and cooldown rates below the critical temperature. Temperature mapping and a novel magnetic field mapping systems were used to find the location of “hot-spots” …


A Compton Transmission Polarimeter For Dc And Srf Electron Photo-Injectors, G. Blume, M. Bruker, C. Cuevas, H. Dong, Benjamin Fernandes Neres, P. Ghoshal, S. Gopinath, J. Grames, S. Gregory, G. Hays, C. Le Galliard, Sylvain Marsillac, B. Moffit, Thi Nguyen Trung, M. Poelker, R. Suleiman, E. Voutier, S. Zhang Jan 2024

A Compton Transmission Polarimeter For Dc And Srf Electron Photo-Injectors, G. Blume, M. Bruker, C. Cuevas, H. Dong, Benjamin Fernandes Neres, P. Ghoshal, S. Gopinath, J. Grames, S. Gregory, G. Hays, C. Le Galliard, Sylvain Marsillac, B. Moffit, Thi Nguyen Trung, M. Poelker, R. Suleiman, E. Voutier, S. Zhang

Physics Faculty Publications

A polarimeter was constructed to measure the longitudinal polarization of a spin-polarized electron beam at 5 and 7 MeV. The polarimeter takes advantage of Compton scattering between circularly polarized bremsstrahlung photons produced by a longitudinally polarized electron beam striking a copper radiator and the spin-polarized electrons orbiting the iron atoms of an analyzing magnet. This so-called Compton transmission polarimeter is compact and relatively inexpensive compared to Mott-scattering polarimeters because no spin manipulator is required. This work presents the design of the radiator, analyzing magnet, photon detector assembly, and data acquisition system of the Compton transmission polarimeter as well as beam …


Field, Frequency, And Temperature Dependencies Of The Surface Resistance Of Nitrogen Diffused Niobium Superconducting Radio Frequency Cavities, P. Dhakal, B. D. Khanal, A. Gurevich, G. Ciovati Jan 2024

Field, Frequency, And Temperature Dependencies Of The Surface Resistance Of Nitrogen Diffused Niobium Superconducting Radio Frequency Cavities, P. Dhakal, B. D. Khanal, A. Gurevich, G. Ciovati

Physics Faculty Publications

We investigate the rf performance of several single-cell superconducting radio-frequency cavities subjected to low temperature heat treatment in nitrogen environment. The cavities were treated at temperature 120–165 °C for an extended period of time (24–48 h) either in high vacuum or in a low partial pressure of ultrapure nitrogen. The improvement in 𝑄0 with a 𝑄 rise was observed when nitrogen gas was injected at ∼300 °C during the cavity cooldown from 800 °C and held at 165 °C, without any degradation in accelerating gradient over the baseline performance. The treatment was applied to several elliptical cavities with frequency ranging …


Cebaf Injector At 200 Kv: K-Long Bunch Charge With Spin Flipper Off/On, Sunil Pokharel, Alicia Hofler, Reza Kazimi, Geoffrey Krafft, Max Bruker, Joe Grames, Riad Suleiman, Shukui Zhang Jan 2024

Cebaf Injector At 200 Kv: K-Long Bunch Charge With Spin Flipper Off/On, Sunil Pokharel, Alicia Hofler, Reza Kazimi, Geoffrey Krafft, Max Bruker, Joe Grames, Riad Suleiman, Shukui Zhang

Physics Faculty Publications

The forthcoming K-Long experiment in Jefferson Lab’s Hall D presents distinct beam requirements, marked by a notably low bunch repetition rate and an unusually high bunch charge. Furthermore, the Continuous Electron Beam Accelerator Facility (CEBAF) Injector requires a parity quality beam for experiments such as the Measurement of a Lepton-Lepton Electroweak Reaction (MOLLER). In this study, to prepare for the upcoming K-Long experiment, using the optimized settings of the magnetic elements and RF amplitude and phases, we conducted simulations covering a range of bunch charge beams, from low to high specifications, while considering concurrent operations across all four Halls at …


Investigation Of Hot-Spots Due To Trapped Flux In Niobium Superconducting Radiofrequency Cavities, B. Khanal, P. Dhakal Jan 2024

Investigation Of Hot-Spots Due To Trapped Flux In Niobium Superconducting Radiofrequency Cavities, B. Khanal, P. Dhakal

Physics Faculty Publications

One of the significant sources of residual losses in superconducting radio-frequency cavities is magnetic flux trapped during the cool-down due to the incomplete Messier effect. If the trapped vortices are non-uniformly distributed on the cavity surface, the temperature mapping revealed the “hot-spots” at the location of high density of pinned vortices. Here, we performed a rf test on 1.3 GHz single cell cavity with the combination of the temperature mapping system. The temperature mapping reveled the development of the hot spots with the increase in rf field inside the cavity. When magnetic field is trapped locally on the surface of …


Rf And Mechanical Design Of A 915 Mhz Srf Cavity For Conduction-Cooled Cryomodules, G. Ciovati, A. Castilla-Loeza, G. Cheng, J. Henry, J. Rathke, J. Vennekate, K. Harding, T. Schultheiss, J. Lewis Jan 2024

Rf And Mechanical Design Of A 915 Mhz Srf Cavity For Conduction-Cooled Cryomodules, G. Ciovati, A. Castilla-Loeza, G. Cheng, J. Henry, J. Rathke, J. Vennekate, K. Harding, T. Schultheiss, J. Lewis

Physics Faculty Publications

Conduction-cooled SRF niobium cavities are being developed for use in compact, continuous-wave electron linear accelerators for a variety of industrial applications. A 915 MHz two-cell cavity has been designed to achieve an energy gain of 3.5 MeV. The design of the cell shape aims at minimizing the peak surface magnetic field. Field flatness is achieved by adjusting the length of the outer end half-cells. The higher-order mode analysis shows that absorbers are not required for a moderate beam current of 5 mA. One of the beam tubes has two side-ports for insertion of coaxial fundamental power couplers. The mechanical design …


Beam Correction For Multi-Pass Arcs In Ffa@ Cebaf: Status Update, A. Coxe, J. F. Benesch, R.M. Bodenstein, K. E. Deitrick, K. Price, T. Satogata Jan 2024

Beam Correction For Multi-Pass Arcs In Ffa@ Cebaf: Status Update, A. Coxe, J. F. Benesch, R.M. Bodenstein, K. E. Deitrick, K. Price, T. Satogata

Physics Faculty Publications

As design and simulation studies for the energy upgrade at the Continuous Electron Beam Accelerator Facility progress, both static and dynamic errors must be addressed. The current upgrade design introduces a pair of Fixed-Field Alternating-Gradient (FFA) recirculating arcs: one in the East recirculating arc, and one in the West. In the present design, each FFA arc supports six concurrent beam energies in the same beam pipe; these must be concurrently corrected for both static and dynamic errors. This document discusses the present beam correction strategies applied in simulation.


Charge Lifetime Improvement Of The Continuous Electron Beam Accelerator Facility Photogun With A Biased Anode, J. T. Yoskowitz, G. A. Krafft, G. Palacios-Serrano, S.A.K. Wijethunga, J. Grames, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, M. L. Stutzman, R. Suleiman, C. A. Valerio-Lizarraga, S. B. Van Der Geer Jan 2024

Charge Lifetime Improvement Of The Continuous Electron Beam Accelerator Facility Photogun With A Biased Anode, J. T. Yoskowitz, G. A. Krafft, G. Palacios-Serrano, S.A.K. Wijethunga, J. Grames, J. Hansknecht, C. Hernandez-Garcia, M. Poelker, M. L. Stutzman, R. Suleiman, C. A. Valerio-Lizarraga, S. B. Van Der Geer

Physics Faculty Publications

GaAs photocathodes in dc high-voltage photoguns are highly susceptible to ion back-bombardment, which reduces the photocathode quantum efficiency and limits the useful operating lifetime for producing polarized electron beams. This paper demonstrates that applying a small positive bias to the photogun anode can significantly suppress ion back-bombardment and increase charge lifetime. This technique was studied extensively using the Continuous Electron Beam Accelerator Facility photogun, where highly polarized electron beams created using a strained-superlattice GaAs/GaAsP photocathode were used and charge lifetimes improved by almost a factor of 2. A new simulation code ionator was developed to model ion production and tracking …


The Continuous Electron Beam Accelerator Facility At 12 Gev, P. A. Adderly, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. Bastaninejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, Y. Zhang, Et Al. Jan 2024

The Continuous Electron Beam Accelerator Facility At 12 Gev, P. A. Adderly, S. Ahmed, T. Allison, R. Bachimanchi, K. Baggett, M. Bastaninejad, B. Bevins, M. Bevins, M. Bickley, R. M. Bodenstein, S. A. Bogacz, M. Bruker, A. Burrill, L. Cardman, J. Creel, Y. -C. Chao, G. Cheng, G. Ciovati, S. Chattopadhyay, Y. Zhang, Et Al.

Physics Faculty Publications

This review paper describes the energy-upgraded Continuous Electron Beam Accelerator Facility (CEBAF) accelerator. This superconducting linac has achieved 12 GeV beam energy by adding 11 new high-performance cryomodules containing 88 superconducting cavities that have operated cw at an average accelerating gradient of 20 MV/m. After reviewing the attributes and performance of the previous 6 GeV CEBAF accelerator, we discuss the upgraded CEBAF accelerator system in detail with particular attention paid to the new beam acceleration systems. In addition to doubling the acceleration in each linac, the upgrade included improving the beam recirculation magnets, adding more helium cooling capacity to …


Event Generators For High-Energy Physics Experiments, J. M. Campbell, M. Diefenthaler, T. J. Hobbs, S. Höche, J. Isaacson, F. Kling, S. Mrenna, J. Reuter, S. Alioli, J. R. Andersen, C. Andreaopoulos, A. M. Ankowski, E.C. Aschenauer, A. Ashkenazi, M. D. Baker, J. L. Barrow, M. Van Beekveld, G. Beswick, S. Bhattacharya, K. Zapp, Et Al. Jan 2024

Event Generators For High-Energy Physics Experiments, J. M. Campbell, M. Diefenthaler, T. J. Hobbs, S. Höche, J. Isaacson, F. Kling, S. Mrenna, J. Reuter, S. Alioli, J. R. Andersen, C. Andreaopoulos, A. M. Ankowski, E.C. Aschenauer, A. Ashkenazi, M. D. Baker, J. L. Barrow, M. Van Beekveld, G. Beswick, S. Bhattacharya, K. Zapp, Et Al.

Physics Faculty Publications

We provide an overview of the status of Monte-Carlo event generators for high-energy particle physics. Guided by the experimental needs and requirements, we highlight areas of active development, and opportunities for future improvements. Particular emphasis is given to physics models and algorithms that are employed across a variety of experiments. These common themes in event generator development lead to a more comprehensive understanding of physics at the highest energies and intensities, and allow models to be tested against a wealth of data that have been accumulated over the past decades. A cohesive approach to event generator development will allow these …


Dual-Energy Electron Storage Ring, B. Dhital, Y. S. Derbenev, A. Hutton, H. Zhang, G. A. Krafft, Y. Zhang, F. Lin, V. S. Morozov Jan 2024

Dual-Energy Electron Storage Ring, B. Dhital, Y. S. Derbenev, A. Hutton, H. Zhang, G. A. Krafft, Y. Zhang, F. Lin, V. S. Morozov

Physics Faculty Publications

A dual-energy electron storage ring is a novel concept initially proposed to cool hadron beams at high energies. The design consists of two closed rings operating at significantly different energies: the low-energy ring and the high-energy ring. These two rings are connected by an energy recovery linac (ERL) that provides the necessary energy difference. The ERL features superconducting radio-frequency (SRF) cavities that first accelerate the beam from the low energy EL to the high energy EH and then decelerate the beam from EH to EL in the next pass. The different SRF cavities in the ERL …


Effects Of Electron Beam Irradiation On Crmnv And Crmntiv High Entropy Alloys: Nano-Mechanical, Structural, And Thermodynamic Perspectives, N. A. Sultana, Y. S. Mohammed, S. J. Pendleton, J. Vennekate, G. Ciovati, X. Li, H. Baumgart, A. A. Elmustafa Jan 2024

Effects Of Electron Beam Irradiation On Crmnv And Crmntiv High Entropy Alloys: Nano-Mechanical, Structural, And Thermodynamic Perspectives, N. A. Sultana, Y. S. Mohammed, S. J. Pendleton, J. Vennekate, G. Ciovati, X. Li, H. Baumgart, A. A. Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

Beam exit windows are crucial components of any particle accelerator as they provide an interface between the beamline vacuum and target material at atmospheric media. For high beam power machines, special materials and designs are required to withstand high radiation and mechanical loads, while minimizing energy loss during transition and maximizing window lifetime. This research investigates the impact of electron beam exposure to bulk CrMnV and CrMnTiV high entropy alloys (HEAs) with the primary goal of identifying suitable candidate materials for the design of robust and durable exit window settings. The selection criteria include intrinsic characteristics, power dissipation, and mechanical …


Understanding Sextupole, T. Zolkin, I. Morozov, S. Nagaitsev Jan 2024

Understanding Sextupole, T. Zolkin, I. Morozov, S. Nagaitsev

Physics Faculty Publications

In this study, we reassess the dynamics within a simple accelerator lattice featuring a single degree of freedom and incorporating a sextupole magnet. In the initial segment, we revisit the Hénon quadratic map, a representation of a general transformation with quadratic nonlinearity. In the subsequent section, we unveil that a conventional sextupole is essentially a composite structure, comprising an integrable McMillan sextupole and octupole, along with non-integrable corrections of higher orders. This fresh perspective sheds light on the fundamental nature of the sextupole magnet, providing a more nuanced understanding of its far-from-trivial chaotic dynamics. Importantly, it enables the description of …


Operation Of A Longitudinally Polarized Solid Nuclear Target Of Clas12, P. Pandey, J. Brock, T. Kageya, C. Keith, S. Kuhn, V. Lagerquist, J. Maxwell, X. Wei Jan 2024

Operation Of A Longitudinally Polarized Solid Nuclear Target Of Clas12, P. Pandey, J. Brock, T. Kageya, C. Keith, S. Kuhn, V. Lagerquist, J. Maxwell, X. Wei

Physics Faculty Publications

A suite of experiments measuring spin observables in electron-nucleon scattering (dubbed Run Group C) was recently executed in Jefferson Lab. These experiments involved the scattering of a polarized 11 GeV electron beam from longitudinally polarized nucleon targets located within the CLAS12 spectrometer in Hall B. The dynamically polarized target used in these experiments was designed and constructed exclusively for operation inside CLAS12 and further optimized for the requirements of Run Group C. We report on the complete target setup, operational experience with the target, the benchmarks achieved using various polarizable and unpolarized materials as well as the preliminary target polarization …


Crabbing Cavity System Development For International Linear Collider, Subashini De Silva Jan 2024

Crabbing Cavity System Development For International Linear Collider, Subashini De Silva

Physics Faculty Publications

The International Liner Collider requires a crabbing system to increase the luminosity of the colliding electron bunches. The ILC has a large crossing angle that requires compensation in order to meet the luminosity requirements. There are several frequency options proposed for the crabbing cavity design. Two crab cavity designs were selected to be prototyped in the pre-lab phase, following the Down Selection Review on Crab Cavity Design held in April 2023. The two rf designs selected are the 1.3 GHz rf-dipole cavity and the 2.6 GHz QMiR cavity. We will be presenting the electromagnetic and mechanical design details of the …