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Where Next with SRF?

Description: RF superconductivity (SRF) has become, over the last ~20 years, the technology of choice to produce RF cavities for particle accelerators. This occurred because of improvements in material and processing techniques as well as the understanding and remediation of practical limitations in SRF cavities. This development effort span ~40 years and Nb has been the material of choice for SRF cavity production. As the performances of SRF Nb cavities are approaching what are considered to be theoretical… more
Date: June 1, 2013
Creator: Ciovati, Gianluigi
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs

Description: We propose a demonstration experiment for a new concept of a 'dogbone' RLA with multi-pass return arcs -- JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we desc… more
Date: June 1, 2013
Creator: Bogacz, Slawomir Alex; Krafft, Geoffrey A.; Morozov, Vasiliy S. & Roblin, Yves R.
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Partner: UNT Libraries Government Documents Department
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Measurements of Martin-Puplett Interferometer Limitations using Blackbody Source

Description: Frequency domain measurements with Martin-Puplett interferometer is one of a few techniques capable of bunch length measurements at the level of ~ 100 fs. As the bunch length becomes shorter, it is important to know and be able to measure the limitations of the instrument in terms of shortest measurable bunch length. In this paper we describe an experiment using a blackbody source with the modified Martin-Puplett interferometer that is routine- ly used for bunch length measurements at the JLab … more
Date: June 1, 2013
Creator: Evtushenko, Pavel E. & Klopf, John M.
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Partner: UNT Libraries Government Documents Department
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STUDY OF THE STABILITY OF PARTICLE MOTION IN STORAGE RINGS. Final Report

Description: During this period, our research was concentrated on the study of beam-beam effects in large storage-ring colliders and coherent synchrotron radiation (CSR) effect in light sources. Our group was involved in and made significant contribution to several international accelerator projects such as the US-LHC project for the design of the LHC interaction regions, the luminosity upgrade of Tevatron and HERA, the design of eRHIC, and the U.S. LHC Accelerator Research Program (LARP) for the future LHC… more
Date: September 7, 2012
Creator: Shi, Jack J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Exploration of Quench Initiation Due to Intentional Geometrical Defects in a High Magnetic Field Region of an SRF Cavity

Description: A computer program which was used to simulate and analyze the thermal behaviors of SRF cavities has been developed at Jefferson Lab using C++ code. This code was also used to verify the quench initiation due to geometrical defects in high magnetic field region of SRF cavities. We built a CEBAF single cell cavity with 4 artificial defects near equator, and this cavity has been tested with T-mapping. The preheating behavior and quench initiation analysis of this cavity will be presented here usin… more
Date: July 1, 2011
Creator: J. Dai, K. Zhao, G.V. Eremeev, R.L. Geng, A.D. Palczewski; Dai, J.; Palczewski, A. D.; Eremeev, G. V.; Geng, R. L. & Zhao, K.
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Partner: UNT Libraries Government Documents Department
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Electron Model Of A Dogbone RLA With Multi-Pass Arcs

Description: The design of a dogbone Recirculated Linear Accelerator, RLA, with linear-field multi-pass arcs was earlier developed [1] for accelerating muons in a Neutrino Factory and a Muon Collider. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Such an RLA may have applications going beyond muon acceleration. This paper describes a possible straightforward test o… more
Date: September 1, 2012
Creator: Beard, Kevin B.; Roblin, Yves R.; Morozov, Vasiliy; Bogacz, Slawomir Alex & Krafft, Geoffrey A.
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Partner: UNT Libraries Government Documents Department
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Application of Chebyshev Formalism to Identify Nonlinear Magnetic Field Components in Beam Transport Systems

Description: An experiment was conducted at Jefferson Lab's Continuous Electron Beam Accelerator Facility to develop a beam-based technique for characterizing the extent of the nonlinearity of the magnetic fields of a beam transport system. Horizontally and vertically oriented pairs of air-core kicker magnets were simultaneously driven at two different frequencies to provide a time-dependent transverse modulation of the beam orbit relative to the unperturbed reference orbit. Fourier decomposition of the pos… more
Date: August 1, 2012
Creator: Spata, Michael
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Compensation Techniques in Accelerator Physics

Description: Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along w… more
Date: May 31, 2011
Creator: Sayed, Hisham Kamal
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Performance of First C100 Cryomodules for the CEBAF 12 GeV Upgrade Project

Description: The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the project is a doubling of the available beam energy of CEBAF from 6 GeV to 12 GeV. This increase in beam energy will be due primarily to the construction and installation of ten "C100" cryomodules in the CEBAF linacs. The C100 cryomodules are designed to deliver an average 108 MV each from a string of eight seven-cell, electropolished superconducting RF cavities operat… more
Date: September 1, 2012
Creator: Drury, Michael A.; Burrill, Andrew B.; Davis, G. Kirk; Hogan, John P.; King, Lawrence; Marhauser, Frank et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Design of the Proposed Low Energy Ion Collider Ring at Jefferson Lab

Description: The polarized Medium energy Electron-Ion Collider (MEIC) envisioned at Jefferson Lab will cover a range of center-of-mass energies up to 65 GeV. The present MEIC design could also allow the accommodation of low energy electron-ion collisions (LEIC) for additional science reach. This paper presents the first design of the low energy ion collider ring which is converted from the large ion booster of MEIC. It can reach up to 25 GeV energy for protons and equivalent ion energies of the same magneti… more
Date: June 1, 2013
Creator: Nissen, Edward W.; Lin, Fanglei; Morozov, Vasiliy & Zhang, Yuhong
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Partner: UNT Libraries Government Documents Department
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Conceptual Design of an Antiproton Generation and Storage Facility

Description: The Antiproton Generation and Storage Facility (AGSF) creates copious quantities of antiprotons, for bottling and transportation to remote cancer therapy centers. The #12;first step in the generation and storage process is to accelerate an intense proton beam down the Main Linac for injection into the Main Ring, which is a Rapid Cycling Synchrotron that accelerates the protons to high energy. The beam is then extracted from the ring into a transfer line and into a Proton Target. Immediately dow… more
Date: October 24, 2006
Creator: Peggs, Stephen
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The JLAB UV Undulator

Description: Recently the JLAB FEL has demonstrated 150 W at 400 nm and 200 W at 700 nm using a 33mm period undulator designed and built by STI Optronics. This paper describes the undulator design and performance. Two key requirements were low phase error, zero steering and offset end fields and small rms trajectory errors. We will describe a new genetic algorithm that allowed phase error minimization to 1.8 degrees while exceeding specifications. The mechanical design, control system and EPICS interface wi… more
Date: May 1, 2013
Creator: Gottschalk, Steven C.; Benson, Steven V. & Moore, Steven Wesley
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Novel Crab Cavity RF Design

Description: A 20-50 MV integrated transverse voltage is required for the Electron-Ion Collider. The most promising of the crab cavity designs that have been proposed in the last five years are the TEM type crab cavities because of the higher transverse impedance. The TEM design approach is extended here to a hybrid crab cavity that includes the input power coupler as an integral part of the design. A prototype was built with Phase I monies and tested at JLAB. The results reported on, and a system for achie… more
Date: March 1, 2011
Creator: Dudas, A.; Neubauer, M. L.; Sah, R.; Rimmer, B. & Wang, H.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Rf System Requirements for JLab’s MEIC Collider Ring

Description: The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. At the top energy are the electron and ion collider rings. For the ion ring, it accelerates five long ion bunches to colliding energy and rebunches ions into a train of very short bunches before colliding. A set of low frequency RF system is needed for the long ion bunch energy ramping. Another set of high frequency RF cavities is needed to rebunch ions. For the electron ring, superc… more
Date: June 1, 2013
Creator: Wang, Shaoheng; Li, Rui; Rimmer, Robert A.; Wang, Haipeng & Zhang, Yuhong
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Exploration of very high gradient cavities

Description: Several of the 9-cell ILC cavities processed at Jlab within ongoing ILC R&D program have shown interesting behavior at high fields, such as mode mixing and sudden field emission turn-on during quench. Equipped with thermometry and oscillating superleak transducer (OST) system for quench detection, we couple our RF measurements with local dissipation measurements. In this contribution we report on our findings with high gradient SRF cavities.
Date: July 1, 2011
Creator: Eremeev, Grigory
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Final Technical Report on STTR Project DE-FG02-06ER86281 Particle Tracking in Matter-Dominated Beam Lines (G4beamline)

Description: This project has been for software development of the G4beamline [1] program, which is a particle-tracking simulation program based on the Geant4 toolkit [2], optimized for beam lines. This program can perform more realistic simulations than most alternatives, while being significantly easier to use by physicists. This project has fostered the general acceptance of G4beamline within the muon community, and has assisted in expanding its role outside that community. During this project, the G4bea… more
Date: May 19, 2011
Creator: Muons, Inc.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Study, design and realization of a Fabry-Perot cavity for the Compton polarimeter of TJNAF; Etude, conception et realisation d'une cavite Fabry-Perot pour le polarimetre Compton de TJNAF

Description: This is a doctoral dissertation, in French, on the subject of study, design and realization of a Fabry-Perot cavity for the Compton polarimeter of TJNAF.
Date: January 1, 2001
Creator: Falletto, M. Nicolas
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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APPLICATION OF NEURAL NETWORK ALGORITHMS FOR BPM LINEARIZATION

Description: Stripline BPM sensors contain inherent non-linearities, as a result of field distortions from the pickup elements. Many methods have been devised to facilitate corrections, often employing polynomial fitting. The cost of computation makes real-time correction difficult, particulalry when integer math is utilized. The application of neural-network technology, particularly the multi-layer perceptron algorithm, is proposed as an efficient alternative for electrode linearization. A process of super… more
Date: November 1, 2012
Creator: Musson, John C.; Seaton, Chad; Spata, Mike F. & Yan, Jianxun
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities

Description: The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the… more
Date: September 1, 2012
Creator: De Silva, Payagalage Subashini Uddika & Delayen, Jean Roger
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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RF Design Optimization for New Injector Cryounit at CEBAF

Description: A new injector superconducting RF (SRF) cryounit with one new 2-cell, B=0.6 cavity plus one refurbished 7-cell, B=0.97, C100 style cavity has been re-designed and optimized for the engineering compatibility of existing module for CEBAF operation. The optimization of 2-cell cavity shape for longitudinal beam dynamic of acceleration from 200keV to 533keV and the minimization of transverse kick due to the waveguide couplers to less than 1 mrad have been considered. Operating at 1497MHz, two caviti… more
Date: June 1, 2013
Creator: Wang, Haipeng; Cheng, Guangfeng; Hannon, Fay E.; Hofler, Alicia S.; Kazimi, Reza; Preble, Joe et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

Description: Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especial… more
Date: June 1, 2013
Creator: Evtushenko, Pavel E. & Douglas, David R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The Calibration of the PEPPo Polarimeter for Electrons and Positrons

Description: The PEPPo (Polarized Electrons for Polarized Positrons) experiment at Jefferson Laboratory investigated the polarization transfer from longitudinally polarized electrons to longitudinally polarized positrons, with the aim of developing this technology for a low energy (~MeV) polarized positron source. Polarization of the positrons was measured by means of a Compton transmission polarimeter where incoming positrons transfer their polarization into circularly polarized photons that were subsequen… more
Date: June 1, 2013
Creator: Adeyemi, Adeleke Hakeem & Voutier, Eric J-.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Source and Extraction for Simultaneous Four-hall Beam Delivery System at CEBAF

Description: A new design for simultaneous delivery of the electron beam to all four 12 GeV CEBAF experimental halls* requires a new 750 MHz RF separator system in the 5th pass extraction region, a 250 MHz repetition rate for its beams, and addition of a fourth laser at the photo-cathode gun. The proposed system works in tandem with the existing 500 MHz RF separators and beam repetition rate on the lower passes. The new 5th pass RF separators will have the same basic design but modified to run at 750 MHz. T… more
Date: June 1, 2013
Creator: Kazimi, Reza; Wang, Haipeng; Spata, Mike F. & Hansknecht, John C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High Dynamic Range Beam Imaging with Two Simultaneously Sampling CCDs

Description: Transverse beam profile measurement with sufficiently high dynamic range (HDR) is a key diagnostic to measure the beam halo, understand its sources and evolution. In this contribution we describe our initial experience with the HDR imaging of the electron beam at the JLab FEL. On contrary to HDR measurements made with wire scanners in counting mode, which provide only two or three 1D projections of transverse beam distribution, imaging allows to measure the distribution itself. That is especial… more
Date: May 1, 2013
Creator: Evtushenko, Pavel; Douglas, David R.; Legg, Robert A. & Tennant, Christopher D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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