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Physics Faculty Publications

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Articles 631 - 660 of 2178

Full-Text Articles in Physical Sciences and Mathematics

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. M. Park, R. W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J. -M. Laget, K. P. Adhikari, Gerard P. Gilfoyle, Et. Al. May 2018

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. M. Park, R. W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J. -M. Laget, K. P. Adhikari, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep→e′nπ+, above the resonance region at backward pion center-of-mass angles. The φπ⁎-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of three-quark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon. Keywords: TDA, Exclusive single pion, Eletroproduction, CLAS

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Measurement Of The Beam Asymmetry Sigma And The Target Asymmetry T In The Photoproduction Of Omega Mesons Off The Proton Using Clas At Jefferson Laboratory, P. Roy, Z. Akbar, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, Gerard P. Gilfoyle May 2018

Measurement Of The Beam Asymmetry Sigma And The Target Asymmetry T In The Photoproduction Of Omega Mesons Off The Proton Using Clas At Jefferson Laboratory, P. Roy, Z. Akbar, S. Park, V. Crede, A. V. Anisovich, I. Denisenko, E. Klempt, Gerard P. Gilfoyle

Physics Faculty Publications

The photoproduction of omega mesons off the proton has been studied in the reaction γp -> pω using the CEBAF Large Acceptance Spectrometer (CLAS) and the frozen-spin target in Hall B at the Thomas Jefferson National Accelerator Facility. For the first time, the target asymmetry T has been measured in photoproduction from the decay ω -> π+π-π0, using a transversely polarized target with energies ranging from just above the reaction threshold up to 2.8 GeV. Significant nonzero values are observed for these asymmetries, reaching about 30-40% in the third-resonance region. New measurements for the …

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Application Of Ampere's Law To A Non-Infinite Wire And To A Moving Charge, Khaled Aledealat, Christopher L. Duston May 2018

Application Of Ampere's Law To A Non-Infinite Wire And To A Moving Charge, Khaled Aledealat, Christopher L. Duston

Physics Faculty Publications

In this work we demonstrate how to apply Ampere's law to a non-infinite wire that is a part of a complete circuit with a steady current. We show that this can be done by considering the magnetic field from the whole circuit, without having to directly introduce the displacement current. This example can be used to isolate and clarify students' confusion about the application of Ampere's law to a short wire. The second part of this work focuses on the application of Ampere's law to a non-relativistic moving charge. It exposes the students to the Dirac delta function in a …

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Power Corrections To Tmd Factorization For Z-Boson Production, I. Balitsky, A. Tatasov May 2018

Power Corrections To Tmd Factorization For Z-Boson Production, I. Balitsky, A. Tatasov

Physics Faculty Publications

A typical factorization formula for production of a particle with a small transverse momentum in hadron-hadron collisions is given by a convolution of two TMD parton densities with cross section of production of the final particle by the two partons. For practical applications at a given transverse momentum, though, one should estimate at what momenta the power corrections to the TMD factorization formula become essential. In this paper we calculate the first power corrections to TMD factorization formula for Z-boson production and Drell-Yan process in high-energy hadron-hadron collisions. At the leading order in Nc power corrections are expressed in …

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Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. Park, M. Guidal, R. W. Gothe, B. Pire, G. Charles, C. E. Hyde, S E. Kuhn, J. Poudel, Y. Prok May 2018

Hard Exclusive Pion Electroproduction At Backward Angles With Clas, K. Park, M. Guidal, R. W. Gothe, B. Pire, G. Charles, C. E. Hyde, S E. Kuhn, J. Poudel, Y. Prok

Physics Faculty Publications

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep → e'nπ+, above the resonance region at backward pion center-of-mass angles. The ϕ∗ π-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of threequark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon.

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U-Band Measurement Of Star Formation In Cluster Galaxies, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer Apr 2018

U-Band Measurement Of Star Formation In Cluster Galaxies, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer

Physics Faculty Publications

We propose to obtain deep U-band observations of 14 low-redshift (z ≤ 0.06) galaxy clusters using the WIYN 0.9m+HDI telescope/detector to complete our survey to probe star formation of galaxies in high-density environments. These observations, combined with previously obtained data of 11 clusters observed using the same telescope+detector, will give us a statistically significant sample for the Ph.D. dissertation of co-I Gihan Gamage. Clusters are selected from 57 clusters in which we have obtained deep B- and R-band data using the KPNO 0.9m+MOSA. U-band data will allow us to explore relative changes in the luminosity function for the U- and …

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Mapping Star Formation From The Core To The Outskirts Of Galaxy Clusters, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer Apr 2018

Mapping Star Formation From The Core To The Outskirts Of Galaxy Clusters, Wayne Barkhouse, Gihan Gamage, Sandanuwa Kalawila, Madina Sultanova, Dean Smith, Elijah Mathews, Haylee Archer

Physics Faculty Publications

We propose for time to complete our u- and r-band imaging program of 30 low-redshift (z ≤ 0.03) galaxy clusters using the CTIO Blanco 4m+DECam telescope/detector combination. These data will allow us to probe star formation from the cluster core to the infall region, and complete the acquisition of observations for the Ph.D. dissertation of Gihan Gamage (University of North Dakota). The deep u- and r-band data will allow us to explore relative changes in the luminosity function, dwarf-to-giant ratio, blue fraction, and galaxy morphological type as a function of cluster-centric radius for a statistically significant sample of 30 clusters. …

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Nucleon And Nuclear Structure Through Dilepton Production, I. V. Anikin, N. Baltzell, M. Boer, R. Boussarie, V. M. Braun, S. J. Brodsky, A. Camsonne, W. C. Chang, L. Colaneri, C. E. Hyde Apr 2018

Nucleon And Nuclear Structure Through Dilepton Production, I. V. Anikin, N. Baltzell, M. Boer, R. Boussarie, V. M. Braun, S. J. Brodsky, A. Camsonne, W. C. Chang, L. Colaneri, C. E. Hyde

Physics Faculty Publications

Transverse momentum distributions and generalized parton distributions provide a comprehensive framework for the three-dimensional imaging of the nucleon and the nucleus experimentally using deeply virtual semi-exclusive and exclusive processes. The advent of combined high luminosity facilities and large acceptance detector capabilities enables experimental investigation of the partonic structure of hadrons with time-like virtual probes, in complement to the rich on-going space-like virtual probe program. The merits and benefits of the dilepton production channel for nuclear structure studies are discussed within the context of the International Workshop on Nucleon and Nuclear Structure through Dilepton Production taking place at the European Center …

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Question 1: Automobile Air Use; Question 2: Personal Air Use, Larry Weinstein Apr 2018

Question 1: Automobile Air Use; Question 2: Personal Air Use, Larry Weinstein

Physics Faculty Publications

The article presents questions and answers regarding the usage of oxygen in a gasoline powered automobile and the time taken to use the amount of oxygen produced in a garbage by a single person.

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Solutions For Fermi Questions, April 2018: Question 1: Automobile Air Use; Question 2: Personal Air Use, Larry Weinstein Apr 2018

Solutions For Fermi Questions, April 2018: Question 1: Automobile Air Use; Question 2: Personal Air Use, Larry Weinstein

Physics Faculty Publications

The article presents questions and answers regarding the use of oxygen by a person and an automobile which is produced by garbage.

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Mixing Enhancement In Serpentine Micromixers With A Non-Rectangular Cross-Section, Joshua Clark, Miron Kaufman, Petru S. Fodor Mar 2018

Mixing Enhancement In Serpentine Micromixers With A Non-Rectangular Cross-Section, Joshua Clark, Miron Kaufman, Petru S. Fodor

Physics Faculty Publications

In this numerical study, a new type of serpentine micromixer involving mixing units with a non-rectangular cross-section is investigated. Similar to other serpentine/spiral shaped micromixers, the design exploits the formation of transversal vortices (Dean flows) in pressure-driven systems, associated with the centrifugal forces experienced by the fluid as it is confined to move along curved geometries. In contrast with other previous designs, though, the use of non-rectangular cross-sections that change orientation between mixing units is exploited to control the center of rotation of the transversal flows formed. The associated extensional flows that thus develop between the mixing segments complement the …

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Fermi Questions, Question 1: Air Pressure On Waves; Question 2: Weight Of Toner, Larry Weinstein Mar 2018

Fermi Questions, Question 1: Air Pressure On Waves; Question 2: Weight Of Toner, Larry Weinstein

Physics Faculty Publications

The article presents questions on the difference in air pressure at the crest and trough of ocean waves because of the Bernoulli effect and the difference in weight between a 100-page printed document and 100 blank pages.

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Solutions For Fermi Questions, March 2018: Question 1: Air Pressure On Waves; Question 2: Weight Of Toner, Larry Weinstein Mar 2018

Solutions For Fermi Questions, March 2018: Question 1: Air Pressure On Waves; Question 2: Weight Of Toner, Larry Weinstein

Physics Faculty Publications

The article presents questions on the difference in air pressure at the crest and trough of ocean waves because of the Bernoulli effect and the difference in weight between a 100-page printed document and 100 blank pages.

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The Radio Synchrotron Background: Conference Summary And Report, Jack Singal, J. Haider, M. Ajello, D. R. Ballantyne, Emory F. Bunn, J. Condon, J. Dowell, Et. Al. Mar 2018

The Radio Synchrotron Background: Conference Summary And Report, Jack Singal, J. Haider, M. Ajello, D. R. Ballantyne, Emory F. Bunn, J. Condon, J. Dowell, Et. Al.

Physics Faculty Publications

We summarize the radio synchrotron background workshop that took place 2017 July 19–21 at the University of Richmond. This first scientific meeting dedicated to the topic was convened because current measurements of the diffuse radio monopole reveal a surface brightness that is several times higher than can be straightforwardly explained by known Galactic and extragalactic sources and processes, rendering it by far the least well understood photon background at present. It was the conclusion of a majority of the participants that the radio monopole level is at or near that reported by the ARCADE 2 experiment and inferred from several …

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Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, Gerard P. Gilfoyle, Et. Al. Feb 2018

Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

The f0 (1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the f0 (1500) via decay into the K-S(0) K-S(0) channel using the CLAS detector. The reaction γp -> fJp -> K-S(0) K-S(0) p, where J = 0,2, was measured with photon energies from 2.7-5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured …

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Erythrocytes And Vascular Function: Oxygen And Nitric Oxide, Christine C. Helms, M. T. Gladwin, Daniel B. Kim-Shapiro Feb 2018

Erythrocytes And Vascular Function: Oxygen And Nitric Oxide, Christine C. Helms, M. T. Gladwin, Daniel B. Kim-Shapiro

Physics Faculty Publications

Erythrocytes regulate vascular function through the modulation of oxygen delivery and the scavenging and generation of nitric oxide (NO). First, hemoglobin inside the red blood cell binds oxygen in the lungs and delivers it to tissues throughout the body in an allosterically regulated process, modulated by oxygen, carbon dioxide and proton concentrations. The vasculature responds to low oxygen tensions through vasodilation, further recruiting blood flow and oxygen carrying erythrocytes. Research has shown multiple mechanisms are at play in this classical hypoxic vasodilatory response, with a potential role of red cell derived vasodilatory molecules, such as nitrite derived nitric oxide and …

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Hill Functions For Stochastic Gene Regulatory Networks From Master Equations With Split Nodes And Time-Scale Separation, Ovidiu Lipan, Cameron Ferwerda Feb 2018

Hill Functions For Stochastic Gene Regulatory Networks From Master Equations With Split Nodes And Time-Scale Separation, Ovidiu Lipan, Cameron Ferwerda

Physics Faculty Publications

The deterministic Hill function depends only on the average values of molecule numbers. To account for the fluctuations in the molecule numbers, the argument of the Hill function needs to contain the means, the standard deviations, and the correlations. Here we present a method that allows for stochastic Hill functions to be constructed from the dynamical evolution of stochastic biocircuits with specific topologies. These stochastic Hill functions are presented in a closed analytical form so that they can be easily incorporated in models for large genetic regulatory networks. Using a repressive biocircuit as an example, we show by Monte Carlo …

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Measurement Of The Q(2) Dependence Of The Deuteron Spin Structure Function G(1) And Its Moments At Low Q(2) With Clas, K. P. Adhikari, A. Deur, L. El Fassi, H. Kang, S. E. Kuhn, M. Ripani, K. Slifer, Gerard P. Gilfoyle, Et. Al. Feb 2018

Measurement Of The Q(2) Dependence Of The Deuteron Spin Structure Function G(1) And Its Moments At Low Q(2) With Clas, K. P. Adhikari, A. Deur, L. El Fassi, H. Kang, S. E. Kuhn, M. Ripani, K. Slifer, Gerard P. Gilfoyle, Et. Al.

Physics Faculty Publications

We measured the g1 spin structure function of the deuteron at low Q2, where QCD can be approximated with chiral perturbation theory (χPT). The data cover the resonance region, up to an invariant mass of W ≈ 1.9  GeV. The generalized Gerasimov-Drell-Hearn sum, the moment Γd1 and the spin polarizability γ0d are precisely determined down to a minimum Q2 of 0.02  GeV2 for the first time, about 2.5 times lower than that of previous data. We compare them to several χPT calculations and models. These results are the first …

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Efficacy Of Multimedia Learning Modules As Preparation For Lecture-Based Tutorials In Electromagnetism, James Christopher Moore Feb 2018

Efficacy Of Multimedia Learning Modules As Preparation For Lecture-Based Tutorials In Electromagnetism, James Christopher Moore

Physics Faculty Publications

We have investigated the efficacy of on-line, multimedia learning modules (MLMs) as preparation for in-class, lecture-based tutorials in electromagnetism in a physics course for natural science majors (biology and marine science). Specifically, we report the results of a multiple-group pre/post-test research design comparing two groups receiving different treatments with respect to activities preceding participation in Tutorials in Introductory Physics. The different pre-tutorial activities were as follows: (1) students were assigned reading from a traditional textbook, followed by a traditional lecture; and (2) students completed on-line MLMs developed by the Physics Education Research Group at the University of Illinois at Urbana …

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Light-Nuclei Spectra From Chiral Dynamics, M. Piarulli, A. Baroni, L. Girlanda, A. Kievsky, A. Lovato, Ewing Lusk, L. E. Marcucci, Steven C. Pieper, R. Schiavilla, M, Viviani, R. B. Wiringa Feb 2018

Light-Nuclei Spectra From Chiral Dynamics, M. Piarulli, A. Baroni, L. Girlanda, A. Kievsky, A. Lovato, Ewing Lusk, L. E. Marcucci, Steven C. Pieper, R. Schiavilla, M, Viviani, R. B. Wiringa

Physics Faculty Publications

In recent years local chiral interactions have been derived and implemented in quantum Monte Carlo methods in order to test to what extent the chiral effective field theory framework impacts our knowledge of few- and many-body systems. In this Letter, we present Green's function Monte Carlo calculations of light nuclei based on the family of local two-body interactions presented by our group in a previous paper in conjunction with chiral three-body interactions fitted to bound- and scattering-state observables in the three-nucleon sector. These interactions include Δ intermediate states in their two-pion-exchange components. We obtain predictions for the energy levels and …

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Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, K. P. Adhikari, S. Adhikari, Z. Akbar, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao, The Clas Collaboration Feb 2018

Double K-S(0) Photoproduction Off The Proton At Clas, S. Chandavar, J. T. Goetz, K. Hicks, D. Keller, M. C. Kunkel, M. Paolone, D. P. Weygand, K. P. Adhikari, S. Adhikari, Z. Akbar, G. Charles, G. Gavalian, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao, The Clas Collaboration

Physics Faculty Publications

The f0(1500) meson resonance is one of several contenders to have significant mixing with the lightest glueball. This resonance is well established from several previous experiments. Here we present the first photoproduction data for the f0(1500) via decay into the K-S(0) K-S(0) channel using the CLAS detector. The reaction γp → fJp → K-S(0) K-S(0) p,where J = 0,2, was measured with photon energies from 2.7–5.1 GeV. A clear peak is seen at 1500 MeV in the background subtracted invariant mass spectra of the two kaons. This is enhanced if the measured four-momentum transfer …

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Lithography-Free, Omnidirectional, Cmos-Compatible Alcu Alloys For Thin-Film Superabsorbers, Mariama Rebello De Sousa Dias, Chen Gong, Zachary A. Benson, Marina S. Leite Jan 2018

Lithography-Free, Omnidirectional, Cmos-Compatible Alcu Alloys For Thin-Film Superabsorbers, Mariama Rebello De Sousa Dias, Chen Gong, Zachary A. Benson, Marina S. Leite

Physics Faculty Publications

Superabsorbers based on metasurfaces have recently enabled the control of light at the nanoscale in unprecedented ways. Nevertheless, the sub‐wavelength features needed to modify the absorption band usually require complex fabrication methods, such as electron‐beam lithography. To overcome the scalability limitations associated with the fabrication of metallic nanostructures, engineering the optical response of superabsorbers by metal alloying is proposed, instead of tuning the geometry/size of the nanoscale building blocks. The superior performance of thin film AlCu alloys as the metallic component of planar bilayer superabsorbers is numerically demonstrated. This alloy outperforms its pure constituents as well as other metals, such …

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Gender Fairness Within The Force Concept Inventory, Adrienne L. Traxler, Rachel Henderson, John Stewart, Gay Stewart, Alexis Papak, Rebecca Lindell Jan 2018

Gender Fairness Within The Force Concept Inventory, Adrienne L. Traxler, Rachel Henderson, John Stewart, Gay Stewart, Alexis Papak, Rebecca Lindell

Physics Faculty Publications

Research on the test structure of the Force Concept Inventory (FCI) has largely ignored gender, and research on FCI gender effects (often reported as “gender gaps”) has seldom interrogated the structure of the test. These rarely crossed streams of research leave open the possibility that the FCI may not be structurally valid across genders, particularly since many reported results come from calculus-based courses where 75% or more of the students are men. We examine the FCI considering both psychometrics and gender disaggregation (while acknowledging this as a binary simplification), and find several problematic questions whose removal decreases the apparent gender …

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First Measurement Of The Ar (E,E')X Cross Section At Jefferson Laboratory, H. Dai, M. Murphy, V. Pandey, D. Abrams, D. Nguyen, B. Aljawrneh, F. Hauenstein, D. W. Higinbotham, Charles Hyde, The Jefferson Lab Hall A Collaboration Jan 2018

First Measurement Of The Ar (E,E')X Cross Section At Jefferson Laboratory, H. Dai, M. Murphy, V. Pandey, D. Abrams, D. Nguyen, B. Aljawrneh, F. Hauenstein, D. W. Higinbotham, Charles Hyde, The Jefferson Lab Hall A Collaboration

Physics Faculty Publications

The success of the ambitious programs of both long- and short-baseline neutrino-oscillation experiments employing liquid-argon time-projection chambers will greatly rely on the precision with which the weak response of the argon nucleus can be estimated. In the E12-14-012 experiment at Jefferson Lab Hall A, we studied the properties of the argon nucleus by scattering a high-quality electron beam off a high-pressure gaseous argon target. Here, we present the measured 40Ar(e,e') double differential cross section at incident electron energy E=2.222 GeV and scattering angle Θ = 15.54°. The data cover a broad range of energy transfers, where quasielastic scattering and …

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Probing The Wave Nature Of Light-Matter Interaction, D. E. Boone, C. H. Jackson, A. T. Swecker, J. S. Hergenrather, K. S. Wenger, O. Kokhan, Balša Terzić, I. Melnikov, I. N. Ivanov, E. C. Stevens, G. Scarel Jan 2018

Probing The Wave Nature Of Light-Matter Interaction, D. E. Boone, C. H. Jackson, A. T. Swecker, J. S. Hergenrather, K. S. Wenger, O. Kokhan, Balša Terzić, I. Melnikov, I. N. Ivanov, E. C. Stevens, G. Scarel

Physics Faculty Publications

The wave-particle duality of light is a controversial topic in modern physics. In this context, this work highlights the ability of the wave-nature of light on its own to account for the conservation of energy in light-matter interaction. Two simple fundamental properties of light as wave are involved: its period and its power P. The power P depends only on the amplitude of the wave’s electric and magnetic fields (Poynting’s vector), and can easily be measured with a power sensor for visible and infrared lasers. The advantage of such a wave-based approach is that it unveils unexpected effects of light’s …

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Cryogenic Probe Station At Old Dominion University Center For Accelerator Science, Junki Makita, Jean R. Delayen, Alex Gurevich, Gianluigi Ciovati Jan 2018

Cryogenic Probe Station At Old Dominion University Center For Accelerator Science, Junki Makita, Jean R. Delayen, Alex Gurevich, Gianluigi Ciovati

Physics Faculty Publications

With a growing effort in research and development of an alternative material to bulk Nb for a superconducting radiofrequency (SRF) cavity, it is important to have a cost effective method to benchmark new materials of choice. At Old Dominion University's Center for Accelerator Science, a cryogenic probe station (CPS) will be used to measure the response of superconductor samples under RF fields. The setup consists of a closed-cycle refrigerator for cooling a sample wafer to a cryogenic temperature, a superconducting magnet providing a field parallel to the sample, and DC probes in addition to RF probes. The RF probes will …

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Cryogenic Test Results Of The Sps Prototype Rf-Dipole Crabbing Cavity With Higher Order Mode Couplers, Subashini De Silva, H. Park, Jean R. Delayen, Z. Li Jan 2018

Cryogenic Test Results Of The Sps Prototype Rf-Dipole Crabbing Cavity With Higher Order Mode Couplers, Subashini De Silva, H. Park, Jean R. Delayen, Z. Li

Physics Faculty Publications

The rf-dipole crabbing cavity planned for the LHC High Luminosity Upgrade is designed to deliver a transverse kick of 3.34 MV; crabbing the proton beam in the horizontal plane. The proton beams of the LHC machine operating at 7 TeV each sets high impedance thresholds on the crabbing cavity systems. The rf-dipole crabbing cavity is designed with a two higher order mode couplers to suppress those HOMs. The first prototype of the HOM couplers are fabricated at Jefferson Lab. This paper reports the cryogenic test results of the HOM couplers with the SPS prototype rf-dipole cavity.

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Determination Of The Field-Dependence Of The Surface Resistance Of Superconductors From Cavity Tests, Jean R. Delayen, Subashini De Silva, Hyekyoung Park Jan 2018

Determination Of The Field-Dependence Of The Surface Resistance Of Superconductors From Cavity Tests, Jean R. Delayen, Subashini De Silva, Hyekyoung Park

Physics Faculty Publications

Cryogenic tests of superconducting cavities yield an average surface resistance as a function of the peak surface magnetic field. An analytical formalism has been developed to extract the actual field dependence of the surface resistance from cavity tests and is applied to coaxial cavities and cavities of more complex geometries.

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Room Temperature Measurements Of Higher Order Modes For The Sps Prototype Rf Dipole Crabbing Cavity, Subashini De Silva, P. Berrutti, Jean R. Delayen, N. A. Huque, Hyekyoung Park Jan 2018

Room Temperature Measurements Of Higher Order Modes For The Sps Prototype Rf Dipole Crabbing Cavity, Subashini De Silva, P. Berrutti, Jean R. Delayen, N. A. Huque, Hyekyoung Park

Physics Faculty Publications

LHC High Luminosity Upgrade will be developing two local crabbing systems to increase the luminosity of the colliding bunches at the ATLAS and CMS experiments. One of the crabbing systems uses the rf-dipole cavity design that will be crabbing the beam in the horizontal plane. The fully integrated crabbing cavity has two higher order mode couplers in damping those excited modes. Currently two sets of HOM couplers have been fabricated at Jefferson Lab for prototyping and testing with the LARP crabbing cavities. This paper presents the measurements of the higher order modes with the prototype HOM couplers carried out at …

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Rf Tests Of Rf-Dipole Prototype Crabbing Cavities For Lhc High Luminosity Upgrade, Subashini De Silva, Hyekyoung Park, Jean R. Delayen, Zi Li Jan 2018

Rf Tests Of Rf-Dipole Prototype Crabbing Cavities For Lhc High Luminosity Upgrade, Subashini De Silva, Hyekyoung Park, Jean R. Delayen, Zi Li

Physics Faculty Publications

The superconducting rf-dipole crabbing cavity is one of the two crabbing cavity designs proposed for the LHC high luminosity upgrade. The proof-of-principle (P-o-P) rf-dipole cavity operating at 400 MHz has demonstrated performance exceeding the design specifications. The prototype cavity for SPS beam test has been designed to include the fundamental power coupler, HOM couplers, and all the ancillary components intended to meet the design requirements. The crab cavities will be installed in the SPS beam line prior to the installation in LHC; this will be the first crabbing cavity operation on a proton beam. The fabrication of two prototype rf-dipole …

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