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2017

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Information Seeking Behaviour Of Journalists In North India, Preeti Mahajan, Praveen Kumar Dr. Jan 2017

Information Seeking Behaviour Of Journalists In North India, Preeti Mahajan, Praveen Kumar Dr.

Library Philosophy and Practice (e-journal)

The study presents a survey of the information seeking behavior of the journalists in north India. It highlights that the journalists mostly use the newspaper libraries once a week Majority of them visit the library to consult the reference books. Most of the respondents are satisfied with the behavior of the library staff and they opine that the newspapers should be digitised.


Employability, National Integration And Public Libraries: Case Of The Beyond Access/Irex Intervention In Nigerian Public Libraries, Nkem Ekene Osuigwe Dr, Neemat Abdulrahim Mrs Jan 2017

Employability, National Integration And Public Libraries: Case Of The Beyond Access/Irex Intervention In Nigerian Public Libraries, Nkem Ekene Osuigwe Dr, Neemat Abdulrahim Mrs

Library Philosophy and Practice (e-journal)

National integration is driven by inclusiveness, a sense of belonging and a strong confidence in the existence and future of a country. Nigeria has been bedeviled by numerous clashes, conflicts and challenges which depict the absence of national integration. Unemployment as a means of satisfaction of human basic needs as typified by Maslow’s hierarchy of needs has been fingered as one of the major causes of lack of social cohesion, feelings of marginalization and confidence in the country as an entity. Studies have pointed to a gap in the set of skills acquired in schools and what 21st century …


An Assessment Of Collaborative Activities Among Nigerian Librarians, Olanike Oladunni Olaniyi, Pius Olatunji Olaojo Dr Jan 2017

An Assessment Of Collaborative Activities Among Nigerian Librarians, Olanike Oladunni Olaniyi, Pius Olatunji Olaojo Dr

Library Philosophy and Practice (e-journal)

This study investigated the positioning of Nigerian libraries in collaboration for library and information science development in Nigeria. A descriptive survey research design was adopted, using cluster sampling technique at the 2014 Annual General Meeting of the Nigerian Library Association held at Owerri, Nigeria. One hundred and fifty (150) copies of the questionnaire were given to librarians from academic, public, special, national and school libraries, 144 copies of the questionnaire were returned out of the 150 copies distributed, interview was also conducted as instrument for collection of data. Recommendations were made towards improving the positioning of Nigerian librarians in collaborations …


Information Needs And Information Seeking Behavior Of Researchers In Nigerian Stored Products Research Institute, Ilorin, Kwara State, Momoh Emmanuel Omeiza, Folorunso Abubakar Lanre Jan 2017

Information Needs And Information Seeking Behavior Of Researchers In Nigerian Stored Products Research Institute, Ilorin, Kwara State, Momoh Emmanuel Omeiza, Folorunso Abubakar Lanre

Library Philosophy and Practice (e-journal)

This study was undertaken to investigate the information needs and information seeking behavior of the researchers in Nigerian Stored Products Research Institute, Ilorin, Kwara State. The study used questionnaire and interview method to obtain data from the respondents. Out of the sixty copies of questionnaire distributed to respondents, fifty-three copies were returned and found useable for the study. There was also an interview with the Director, library services in the institute. Findings from the study revealed that the information needs of the researchers were mainly on current awareness, to prepare for promotion exercises and job interviews and to prepare for …


Exchanges Between The Shelf And The Deep Black Sea: An Integrated Analysis Of Physical Mechanisms, Gi Shapiro, F Wobus, A Zatsepin, T Akivis, F Zhou Jan 2017

Exchanges Between The Shelf And The Deep Black Sea: An Integrated Analysis Of Physical Mechanisms, Gi Shapiro, F Wobus, A Zatsepin, T Akivis, F Zhou

School of Biological and Marine Sciences

This study provides an integrated analysis of exchanges of water, salt and heat between the north-western Black Sea shelf and the deep basin. Three contributing physical mechanisms are quantified, namely: Ekman drift, transport by mesoscale eddies at the edge of the NW Black Sea shelf and non-local cascading assisted by the rim current and mesoscale eddies.


Bottom Trapped Internal Waves Over The Malin Sea Continental Slope, Nataliya Stashchuk, Vasiliy Vlasenko Jan 2017

Bottom Trapped Internal Waves Over The Malin Sea Continental Slope, Nataliya Stashchuk, Vasiliy Vlasenko

School of Biological and Marine Sciences

Three-dimensional dynamics of internal tides on the continental slope of the Malin Sea is studied numerically and validated with the observational data collected on the 88-th cruise of the RRS “James Cook” in June–July 2013. Observed in-situ bottom intensification of baroclinic tidal currents was reproduced in a series of numerical experiments using the Massachusetts Institute of Technology general circulation model. The baroclinic tidal dynamics is explained in terms of superposition of two wave processes developing in the area. One of them is a tidal beam generated at the shelf break and radiating tidal energy downward into abyss. The second important …


Contents Jan 2017

Contents

The Bridge

No abstract provided.


Full Issue Jan 2017

Full Issue

The Bridge

No abstract provided.


Best And Worst Case Permutations For Random Online Domination Of The Path, Jonathan Dewitt, Christopher Coscia, Fan Yang, Yiguang Zhang Jan 2017

Best And Worst Case Permutations For Random Online Domination Of The Path, Jonathan Dewitt, Christopher Coscia, Fan Yang, Yiguang Zhang

Mathematics & Statistics Faculty Scholarship

No abstract provided.


Three Essays On Trade And Local Labor Markets, Sandeep Sharma Jan 2017

Three Essays On Trade And Local Labor Markets, Sandeep Sharma

Graduate Theses, Dissertations, and Problem Reports (ETD)

This dissertation studies the effect of trade on wage dispersion, crime rates and alcohol consumption at the local labor market level in the the U.S. The first chapter develops a new measure for skill to investigate the effects of offshoring on wages of three types of workers: high-skilled, medium-skilled, and low-skilled. I also look at the effect of offshoring on wages of offshorable occupations. Although the previous literature emphasizes the impact of offshoring on the skill premium, I find that job characteristics such as offshorability is critical in explaining the wage effect. Chapter 2 analyzes the effects of increasing import …


Dynamical Processes Of Gravity Waves Propagation And Dissipation, And Statistical Characteristics Of Their Momentum Flux In The Mesosphere And Lower Thermosphere, Bing Cao Jan 2017

Dynamical Processes Of Gravity Waves Propagation And Dissipation, And Statistical Characteristics Of Their Momentum Flux In The Mesosphere And Lower Thermosphere, Bing Cao

Doctoral Dissertations and Master's Theses

The mesosphere and lower thermosphere (MLT) (⇠80–110 km) is dominated by abundant atmospheric waves, of which gravity waves are one of the least understood due to large varieties in wave characteristics as well as potential sources. Gravity waves play an important role in the atmosphere by influencing the thermal balance and helping to drive the global circulation. But due to their sub-grid scale, the effects of gravity waves in General Circulation Models (GCMs) are mostly parameterized. The investigations of gravity waves in this dissertation are from two perspectives: the dynamical processes of gravity wave propagation and dissipation in the MLT …


Rf Superconductivity, Jean R. Delayen Jan 2017

Rf Superconductivity, Jean R. Delayen

Physics Faculty Publications

Tutorial, based on the "RF Superconductivity" course taught by J. Delayen at the US PAS.


Status Of The Bonus12 Radial Time Projection Chamber, Gabriel Charles, Stephen Bueltmann, Gail Dodge, Nathan Dzbenski, Mathieu Ehrhardt, Sebastian E. Kuhn, David Payette, Jiwan Poudel, Keith A. Griffioen, Pascal Baron, Irakli Mandjavidze, Eric Christy, I. Hakki Albayrak, Aruni Nadeeshani, Howard Fenker, Narbe Kalantarians, Jixie Zhang, Carlos Ayerbe Gayoso Jan 2017

Status Of The Bonus12 Radial Time Projection Chamber, Gabriel Charles, Stephen Bueltmann, Gail Dodge, Nathan Dzbenski, Mathieu Ehrhardt, Sebastian E. Kuhn, David Payette, Jiwan Poudel, Keith A. Griffioen, Pascal Baron, Irakli Mandjavidze, Eric Christy, I. Hakki Albayrak, Aruni Nadeeshani, Howard Fenker, Narbe Kalantarians, Jixie Zhang, Carlos Ayerbe Gayoso

Physics Faculty Publications

Part of the experimental program in Hall B of the Jefferson Lab, Virginia, USA is dedicated to studying neutron structure functions using deep inelastic scattering on nuclei. For this purpose, the BONuS12 experiment will detect low momentum recoil protons in coincidence with scattered electrons. The protons will be detected by a second-generation Radial Time Projection Chamber (RTPC) using triple Gas Electron Multiplier foils for amplification while the scattered electrons will be detected by the CLAS12 spectrometer installed in Hall B. The following article presents the status of the BONuS12 RTPC detector that will take data within the next 2 years. …


Differential Cross Sections And Polarization Observables From Clas K* Photoproduction And The Search For New N* States, A.V. Anisovich, K. Hicks, E. Klempt, V. A. Nikonov, A. Sarantsev, W. Tang, D. Adhikaram, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, R. A. Badui, J. Ball, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, W. J. Briscoe, V. D. Burkert, D. S. Carman, I Zonta Jan 2017

Differential Cross Sections And Polarization Observables From Clas K* Photoproduction And The Search For New N* States, A.V. Anisovich, K. Hicks, E. Klempt, V. A. Nikonov, A. Sarantsev, W. Tang, D. Adhikaram, Z. Akbar, M. J. Amaryan, S. Anefalos Pereira, R. A. Badui, J. Ball, M. Battaglieri, V. Batourine, I. Bedlinskiy, A. S. Biselli, W. J. Briscoe, V. D. Burkert, D. S. Carman, I Zonta

Physics Faculty Publications

The reaction 𝛄p → K⁎⁺Λ was measured using the CLAS detector for photon energies between the threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. For the first time, spin-density matrix elements have been extracted for this reaction. Differential cross sections, spin density matrix elements, and the Λ recoil polarization are compared with theoretical predictions using the BnGa partial wave analysis. The main result is the evidence for significant contributions from N(1895)1/2- and N(2100)1/2⁺ to the reaction. Branching ratios for decays into K⁎Λ for these resonances and further resonances are reported.


Measurement Of Deep Exclusive Π- Production Using A Transversely Polarized ³He Target And Solid Spectrometer, J. Arrington, K. Hafidi, M. Hattawy, P. Reimer, S. Riordan, Z. Ye, Z. Ahmed, G. R. Ambrose, S. Basnet, R. S. Evans, G. M. Huber, W. Li, D. Paudyal, Z. Papandreou, H. Gao, X. Li, T. Liu, C. Peng, W. Xiong, X. F. Yan, Z. Zhao, A. Camsonne, J-P. Chen, S. Covrig-Dusa, D. Gaskell, T. Brecelj, M. Milhovilovič, S. Širca, S. Štajner, K. Aniol, M. Boer, D. Dutta, L. Ye, C. E. Hyde, F. R. Wesselmann, P. Markowitz, V. Sulkosky, E. Voutier Jan 2017

Measurement Of Deep Exclusive Π- Production Using A Transversely Polarized ³He Target And Solid Spectrometer, J. Arrington, K. Hafidi, M. Hattawy, P. Reimer, S. Riordan, Z. Ye, Z. Ahmed, G. R. Ambrose, S. Basnet, R. S. Evans, G. M. Huber, W. Li, D. Paudyal, Z. Papandreou, H. Gao, X. Li, T. Liu, C. Peng, W. Xiong, X. F. Yan, Z. Zhao, A. Camsonne, J-P. Chen, S. Covrig-Dusa, D. Gaskell, T. Brecelj, M. Milhovilovič, S. Širca, S. Štajner, K. Aniol, M. Boer, D. Dutta, L. Ye, C. E. Hyde, F. R. Wesselmann, P. Markowitz, V. Sulkosky, E. Voutier

Physics Faculty Publications

We propose to measure the transverse nucleon, single-spin asymmetries AUT (Φ, Φs) in the exclusive n→(e, e'π-)p reaction, during the transversely polarized ³He target SIDIS experiment (i.e. E12-10-006 [1]) with SoLID [2]. In principle, as many as six azimuthal modulations of the form Asin(μΦ+λΦS)/UT contribute (where μ and λ are integers) [3], but four of these modulations are small and the physics interest is concentrated in the largest two.

Our primarily goal is the measurment of A sin (Φ-Φs)/UT. This polarization observable has been noted as being sensitive to the spin-flip generalized parton distribution (GPD) E, and factorization studies have …


Question 1: Time Texting; Question 2: Opening Doors, Larry Weinstein Jan 2017

Question 1: Time Texting; Question 2: Opening Doors, Larry Weinstein

Physics Faculty Publications

[Introduction] How much total time do Americans spend texting every year?

Can a typical human open a 20-ton door (swinging on hinges around a vertical axis like a normal room door) with no mechanical assistance?


Differential Cross Section Measurements For Γn→Π-P Above The First Nucleon Resonance Region, P. T. Mattione, D. S. Carman, I. I. Strakovsky, R. L. Workman, A. E. Kudryavtsev, A. Svarc, V. E. Tarasov, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, Z. W. Zhao Jan 2017

Differential Cross Section Measurements For Γn→Π-P Above The First Nucleon Resonance Region, P. T. Mattione, D. S. Carman, I. I. Strakovsky, R. L. Workman, A. E. Kudryavtsev, A. Svarc, V. E. Tarasov, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, Z. W. Zhao

Physics Faculty Publications

The quasifree γd→π-p(p) differential cross section has been measured with CLAS at photon beam energies Eγ from 0.445 to 2.510 GeV (corresponding to W from 1.311 to 2.366 GeV) for pion center-of-mass angles cosθπc.m. from -0.72 to 0.92. A correction for final state interactions has been applied to these data to extract the γn→π-p differential cross sections. These cross sections are quoted in 8428 (Eγ,cosθπc.m.) bins, a factor of nearly 3 increase in the world statistics for this channel in this kinematic range. These new data …


Photon Beam Asymmetry Σ In The Reaction →Γ P → Pω For Eγ = 1.152 To 1.876 Gev, P. Collins, B. G. Ritchie, M. Dugger, F. J. Klein, A. V. Anisovich, E. Klempt, V. A. Nikonov, A. Sarantsev, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao Jan 2017

Photon Beam Asymmetry Σ In The Reaction →Γ P → Pω For Eγ = 1.152 To 1.876 Gev, P. Collins, B. G. Ritchie, M. Dugger, F. J. Klein, A. V. Anisovich, E. Klempt, V. A. Nikonov, A. Sarantsev, K. P. Adhikari, S. Adhikari, D. Adikaram, G. Charles, M. Khachatryan, A. Klein, Y. Prok, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Photon beam asymmetry Σ measurements for ω photoproduction in the reaction γ → p → ω p are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between t-channel meson …


Coincidence Charged-Current Neutrino-Induced Deuteron Disintegration For 2H216O, J. W. Van Orden, T. W. Donnelly, O. Moreno Jan 2017

Coincidence Charged-Current Neutrino-Induced Deuteron Disintegration For 2H216O, J. W. Van Orden, T. W. Donnelly, O. Moreno

Physics Faculty Publications

Semi-inclusive charge-changing neutrino reactions on targets of heavy water are investigated with the goal of determining the relative contributions to the total cross section of deuterium and oxygen in kinematics chosen to emphasize the former. The study is undertaken for conditions where the typical neutrino beam energies are in the few GeV region, and hence relativistic modeling is essential. For this, the previous relativistic approach for the deuteron is employed, together with a spectral function approach for the case of oxygen. Upon optimizing the kinematics of the final-state particles assumed to be detected (typically a muon and a proton) it …


Determination Of The Proton Spin Structure Functions For 0.05 < Q2 <5gev2 Using Clas, R. G. Fersch, N. Guler, P. Bosted, A. Deur, K. Griffioen, C. Keith, S E. Kuhn, R. Minehart, Y. Prok, K. P. Adhikari, S. Bültmann, S. Careccia, Gail Dodge, V. G. Lagerquist, L. B. Weinstein Jan 2017

Determination Of The Proton Spin Structure Functions For 0.05 < Q2 <5gev2 Using Clas, R. G. Fersch, N. Guler, P. Bosted, A. Deur, K. Griffioen, C. Keith, S E. Kuhn, R. Minehart, Y. Prok, K. P. Adhikari, S. Bültmann, S. Careccia, Gail Dodge, V. G. Lagerquist, L. B. Weinstein

Physics Faculty Publications

We present the results of our final analysis of the full data set of gp1 Q2, the spin structure function of the proton, collected using CLAS at Jefferson Laboratory in 2000-2001. Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.7 GeV were scattered from proton targets 15NH3 dynamically polarized along the beam direction) and detected with CLAS. From the measured double spin asymmetries, we extracted virtual photon asymmetries Ap1 and Ap2 and spin structure functions g p1 and gp2 over a wide kinematic range (0.05 GeV …


Measurement Of The Differential And Total Cross Sections Of The ᵧd→Kºʌ(P) Reaction Within The Resonance Region, N. Compton, C. E. Taylor, K. Hicks, P. Cole, N. Zachariou, Y. Ilieva, P. Nadel-Turonski, E. Klempt, V. A. Nikonov, A. V. Sarantsev, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, B. Torayev, J. Zhang Jan 2017

Measurement Of The Differential And Total Cross Sections Of The ᵧd→Kºʌ(P) Reaction Within The Resonance Region, N. Compton, C. E. Taylor, K. Hicks, P. Cole, N. Zachariou, Y. Ilieva, P. Nadel-Turonski, E. Klempt, V. A. Nikonov, A. V. Sarantsev, C. E. Hyde, M. Khachatryan, A. Klein, Y. Prok, B. Torayev, J. Zhang

Physics Faculty Publications

We report the first measurement of differential and total cross sections for the γd →K0 Λ(p)reaction, using data from the CLAS detector at the Thomas Jefferson National Accelerator Facility. Data collected during two separate experimental runs were studied with photon-energy coverage 0.8-3.6 GeV and 0.5-2.6 GeV, respectively. The two measurements are consistent giving confidence in the method and determination of systematic uncertainties. The cross sections are compared with predictions from the KAON-MAID theoretical model (without kaon exchange), which deviate from the data at higher W and at forward kaon angles. These data, along with previously published cross sections for …


Nucleon-Nucleon Correlations, Short-Lived Excitations, And The Quarks Within, Or Hen, Gerald A. Miller, Eli Piasetzky, Lawrence B. Weinstein Jan 2017

Nucleon-Nucleon Correlations, Short-Lived Excitations, And The Quarks Within, Or Hen, Gerald A. Miller, Eli Piasetzky, Lawrence B. Weinstein

Physics Faculty Publications

This article reviews our current understanding of how the internal quark structure of a nucleon bound in nuclei differs from that of a free nucleon. The interpretation of measurements of the European Muon Collaboration (EMC) effect for valence quarks, a reduction in the deep inelastic scattering cross-section ratios for nuclei relative to deuterium, and its possible connection to nucleon-nucleon short-range correlations (SRCs) in nuclei are focused on. This review and new analysis (involving the amplitudes of non-nucleonic configurations in the nucleus) of the available experimental and theoretical evidence shows that there is a phenomenological relation between the EMC effect and …


Target And Beam-Target Spin Asymmetries In Exclusive Pion Electroproduction For Q² > 1 Gev² . Ii. Ep→ Eπºp, Clas Collaboration, K. P. Adhikari, D. Adikaram, M. J. Amaryan, S. Bültmann, N. Guler, S E. Kuhn, A. Klein, S. Koirala, B. Torayev, J. Zhang, Z. W. Zhao Jan 2017

Target And Beam-Target Spin Asymmetries In Exclusive Pion Electroproduction For Q² > 1 Gev² . Ii. Ep→ Eπºp, Clas Collaboration, K. P. Adhikari, D. Adikaram, M. J. Amaryan, S. Bültmann, N. Guler, S E. Kuhn, A. Klein, S. Koirala, B. Torayev, J. Zhang, Z. W. Zhao

Physics Faculty Publications

Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive π0 electroproduction reaction γ∗p→pπ0, expanding an analysis of the γ∗p→nπ+ reaction from the same experiment. The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic ranges covered are 1.1 < W < 3 GeV and 1 < Q2< 6 GeV2 . Results were obtained for about 5700 bins in W, Q2, cos(θ∗) , and ϕ∗. The beam-target asymmetries were found to generally be greater than zero, with …


Long-Term Simulations Of Beam-Beam Dynamics On Gpus, B. Terzić, K. Arumugam, R. Majeti, C. Cotnoir, M. Stefani, D. Ranjan, A. Godunov, V. Morozov, H. Zhang, F. Lin, Y. Roblin, E. Nissen, T. Satogata Jan 2017

Long-Term Simulations Of Beam-Beam Dynamics On Gpus, B. Terzić, K. Arumugam, R. Majeti, C. Cotnoir, M. Stefani, D. Ranjan, A. Godunov, V. Morozov, H. Zhang, F. Lin, Y. Roblin, E. Nissen, T. Satogata

Physics Faculty Publications

Future machines such as the electron-ion colliders (JLEIC), linac-ring machines (eRHIC) or LHeC are particularly sensitive to beam-beam effects. This is the limiting factor for long-term stability and high luminosity reach. The complexity of the non-linear dynamics makes it challenging to perform such simulations which require millions of turns. Until recently, most of the methods used linear approximations and/or tracking for a limited number of turns. We have developed a framework which exploits a massively parallel Graphical Processing Units (GPU) architecture to allow for tracking millions of turns in a sympletic way up to an arbitrary order and colliding them …


Simulations Of Coherent Synchrotron Radiation On Parallel Hybrid Gpu/Cpu Platform, B. Terzić, K. Arumugam, D. Duffin, A. Godunov, T. Islam, D. Ranjan, S. Sangam, Mohammad Zubair Jan 2017

Simulations Of Coherent Synchrotron Radiation On Parallel Hybrid Gpu/Cpu Platform, B. Terzić, K. Arumugam, D. Duffin, A. Godunov, T. Islam, D. Ranjan, S. Sangam, Mohammad Zubair

Physics Faculty Publications

Coherent synchrotron radiation (CSR) is an effect of self-interaction of an electron bunch as it traverses a curved path. It can cause a significant emittance degradation, as well as fragmentation and microbunching. Numerical simulations of the 2D/3D CSR effects have been extremely challenging due to computational bottlenecks associated with calculating retarded potentials via integrating over the history of the bunch. We present a new high-performance 2D, particle-in-cell code which uses massively parallel multicore GPU/GPU platforms to alleviate computational bottlenecks. The code formulates the CSR problem from first principles by using the retarded scalar and vector potentials to compute the self-interaction …


Optimization Of The Rf Cavity Heat Load And Trip Rates For Cebaf At 12 Gev, H. Zhang, Y. Roblin, A. Freyberger, G. Krafft, B. Terzić Jan 2017

Optimization Of The Rf Cavity Heat Load And Trip Rates For Cebaf At 12 Gev, H. Zhang, Y. Roblin, A. Freyberger, G. Krafft, B. Terzić

Physics Faculty Publications

The Continuous Electron Beam Accelerator Facility at JLab has 200 RF cavities in the north linac and the south linac respectively after the 12 GeV upgrade. The purpose of this work is to simultaneously optimize the heat load and the trip rate for the cavities and to reconstruct the pareto-optimal front in a timely manner when some of the cavities are turned down. By choosing an efficient optimizer and strategically creating the initial gradients, the pareto-optimal front for no more than 15 cavities down can be re-established within 20 seconds.


Effects Of Crab Cavity Multipoles On Jleic Ion Ring Dynamic Aperature, S. I. Sosa, V. S. Morozov, S. U. Desilva, J. R. Delayen Jan 2017

Effects Of Crab Cavity Multipoles On Jleic Ion Ring Dynamic Aperature, S. I. Sosa, V. S. Morozov, S. U. Desilva, J. R. Delayen

Physics Faculty Publications

We study the effects of crab cavity multipole fields on the beam dynamic aperture of the Jefferson Lab Electron-Ion Collider (JLEIC) ion ring. Crab cavities are needed to compensate for luminosity loss due to a 50 mrad crossing angle at the interaction point. New compact crab cavity designs are interesting as they do not require considerable space in the ring but their non-linear field needs to be well understood. In this contribution, we study the impact of field multipoles on the beam dynamic aperture and report tolerance values for crab cavity multipoles.


Higher Order Multipole Analysis For 952.6 Mhz Superconducting Crabbing Cavities For Jefferson Lab Electron-Ion Collider, S. U. Desilva, H. Park, J. R. Delayen Jan 2017

Higher Order Multipole Analysis For 952.6 Mhz Superconducting Crabbing Cavities For Jefferson Lab Electron-Ion Collider, S. U. Desilva, H. Park, J. R. Delayen

Physics Faculty Publications

The proposed electron ion collider at Jefferson Lab requires a crabbing cavity system to increase the luminosity in the colliding beams. Currently several superconducting crabbing cavity designs are being reviewed as the design option for the crabbing cavity. Knowledge of higher order mode multipole field effects is important for accurate beam dynamics study for the crabbing system, in selecting the design that meets the design specifications. The multipole components can be accurately determined numerically using the electromagnetic field data in the rf structure. This paper discusses the detailed analysis of higher order multipole components for the operating crabbing mode and …


Front Matter Jan 2017

Front Matter

East Texas Historical Journal

No abstract provided.


Ethj Vol-55 No-1 Jan 2017

Ethj Vol-55 No-1

East Texas Historical Journal

No abstract provided.