Download or read book Performance of the FEL Cryomodules written by Michael Drury and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Performance of the FEL Cryomodules written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Thomas Jefferson National Accelerator Facility (Jefferson Lab, formerly known as CEBAF) is building a highly efficient, kilowatt-level infrared free-electron laser, the IR Demo FEL. The IR FEL uses superconducting radio-frequency (SRF) cavities to accelerate the electron beam that provides energy for the laser. These cavities provide the high-gradient acceleration for the high average currents necessary for a compact FEL design. Currently, a quarter cryomodule injector and a full eight-cavity cryomodule have been installed in the FEL linac. These units were tested as part of the IR FEL commissioning process. The main focus of these tests was to determine the maximum stable operating gradient. The average maximum gradient reached by these ten cavities was 11 Mv/m. Other tests include measurement of cavity parameters such as the unloaded Q (Qo) vs. gradient, the input coupling, calibration of field probes and behavior of the tuner mechanisms. This paper presents the results of those tests.
Download or read book Production and Performance of the CEBAF Upgrade Cryomodule Intermediate Prototypes written by T. Powers and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have installed two new cryomodules, one in the nuclear physics accelerator (CEBAF) and the other in the Free Electron Laser (FEL) of Jefferson Lab. The new cryomodules consist of 7-cell cavities with the original CEBAF cell shape and were designed to deliver gradients of 70 MV/module. Several significant design innovations were demonstrated in these cryomodules. This paper describes the production procedures, the performance characteristics of these cavities in vertical tests, results of tests in the new cryomodule test facility (CMTF) as well as the commissioning in the CEBAF tunnel and FEL. Performances and limitations after installation in the accelerators are discussed in this paper along with improvements proposed for future cryomodules.
Download or read book HOM Damping Performance of JLAB SL21 Cryomodule written by C. Thomas and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The new SL21 cryomodule is the first 70MeV, 8-cavity string superconducting accelerator module to be installed in CEBAF. Each cavity has 7-cells, the center cells have Mark II shape and the end cells have the Mark III shape. The HOM couplers resemble the DESY welded type; two of them assembled at one end of a cavity outside of tuner hub, with 115{sup o} azimuthal apart. There is a {lambda}/4 stub fundamental power waveguide at other end of cavity. The first two passbands of TE111 and TM110 modes have to be damped to avoid beam breakup (BBU) problem at 460{micro}A current. External Q's of the HOM couplers and waveguide were measured on a copper model, on cold niobium cavities and finally in the cryomodule test without beam. This paper presents all HOM data associated with this structure. A threshold current calculated by MATBBU based on the real beam optics and HOM spectrums will be discussed. This information will also benefit next or a high beam current FEL cryomodule HOM.
Download or read book JLab CW Cryomodules for 4th Generation Light Sources written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fourth generation light sources hold the prospect of unprecedented brightness and optical beam quality for a wide range of scientific applications. Many of the proposed new facilities will rely on large superconducting radio frequency (SRF) based linacs to provide high energy, low emittance CW electron beams. For high average power applications there is a growing acceptance of energy recovery linac (ERL) technology as the way to support large recirculating currents with modest RF power requirements. CW SRF and high current ERLs are two core competencies at Jefferson Lab. JLab has designed and built a number of CW cryomodules of several different types starting with the original CEBAF design, with variations for higher current in the two generations of JLab's free-electron laser (FEL), through two intermediate prototypes to the final high-performance module for the 12 GeV upgrade. Each of these represent fully engineered and tested configurations with a variety of specifications that could be considered for possible use in fourth generation light sources. Furthermore JLab has been actively pursuing advanced concepts for highcurrent high-efficiency cryomodules for next generation ERL based FEL's. These existing and proposed designs span the range from about 1mA single-pass to over 100 mA energy recovered current capability. Specialized configurations also exist for high-current non-energy recovered sections such as the injector region where very high RF power is required. We discuss the performance parameters of these existing and proposed designs and their suitability to different classes of fourth generation light sources.
Download or read book Ange Pitou written by Alexandre Dumas and published by . This book was released on 2011-09 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Design and Fabrication of an FEL Injector Cryomodule written by M. Cole and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced Energy Systems has recently completed the design of a four cavity cryomodule for use as an FEL injector accelerator on the JLAB Injector Test Stand. Fabrication is nearing completion. Four 748.5 MHz single cell superconducting cavities have been completed and are currently at Jefferson Lab for final processing and test prior to integration in the module. This paper will review the design and fabrication of the cavities and cryomodule.
Download or read book Jefferson Lab IR FEL Cryomodule Modifications and Test Results written by and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Infrared Free Electron Laser being constructed at the Thomas Jefferson National Accelerator Facility will require a 42 MeV, 5 mA electron accelerator. The accelerator design requires a 10 MeV injector and a two pass 32 MeV linac, one pass for acceleration and one pass for energy recovery. In order to minimize the cost of the linac, standard CEBAF 1497 MHZ Superconducting Radio Frequency cavities and cryomodules are being used with minimal changes. Two SRF cavities, housed in a quarter cryomodule, operate at a nominal 10 MV/m to provide the injector energy. The linac is composed of one cryomodule, housing eight SRF cavities operating at an average gradient of 8 MV/m. The modifications to the cryomodule are being made to handle the higher beam current, to improve RF control, and to increase machine reliability. The modifications to the higher order mode (HOM) loads, cavity tuners, cavity beam line, warm and cold RF windows, and cryogenic shield are described. Test results from the injector quarter cryomodule are also presented.
Download or read book Performance of First C100 Cryomodules for the CEBAF 12 GeV Upgrade Project written by and published by . This book was released on 2012 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 operating at an average accelerating gradient of 19.2 MV/m. The new cryomodules fit in the same available linac space as the original CEBAF 20 MV cryomodules. Cryomodule production started in September 2010. Initial acceptance testing started in June 2011. The first two C100 cryomodules were installed and tested from August 2011 through October 2011, and successfully operated during the last period of the CEBAF 6 GeV era, which ended in May 2012. This paper will present the results of acceptance testing and commissioning of the C100 style cryomodules to date.
Download or read book High Energy Density and High Power RF written by David K. Abe and published by Springer Science & Business Media. This book was released on 2006-01-04 with total page 526 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the seventh in a series of international workshops on high-power and high-energy density microwave devices for accelerator, plasma physics, and defense applications. The scope of this workshop included accelerators for high energy physics, plasma heating and current drive in controlled thermonuclear fusion research, radar and directed energy/high power microwave systems, THz sources and technologies, and advanced 2D/3D computational tool development.
Download or read book JLab High Current CW Cryomodules for ERL and FEL Applications written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe the activities underway at JLab to develop new CW cryomodules capable of transporting up to Ampere-levels of beam currents for use in ERLs and FELs. Goals include an efficient cell shape, high packing factor for efficient real-estate gradient and very strong HOM damping to push BBU thresholds up by two or more orders of magnitude compared to existing designs. Cavity shape, HOM damping and ancillary components are optimized for this application. Designs are being developed for low-frequency (750 MHz), Ampere-class compact FELs and for high-frequency (1.5 GHz), 100 mA configurations. These designs and concepts can easily be scaled to other frequencies. We present the results of conceptual design studies, simulations and prototype measurements. These modules are being developed for the next generation ERL based high power FELs but may be useful for other applications such as high energy light sources, electron cooling, electron-ion colliders, industrial processing etc.
Download or read book CEBAF Upgrade written by and published by . This book was released on 2014 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Thomas Jefferson National Accelerator Facility is currently engaged in the 12 GeV Upgrade Project. The goal of the 12 GeV Upgrade is a doubling of the available beam energy of the Continuous Electron Beam Accelerator Facility (CEBAF) from 6 GeV to 12 GeV. This increase in beam energy will be due in large part to the addition of ten C100 cryomodules plus associated new RF in the CEBAF linacs. The C100 cryomodules are designed to deliver 100 MeV per installed cryomodule. Each C100 cryomodule is built around a string of eight seven-cell, electro-polished, superconducting RF cavities. While an average performance of 100MV per cryomodule is needed to achieve the overall 12 GeV beam energy goal, the actual performance goal for the cryomodules is an average energy gain of 108 MV to provide operational headroom. Cryomodule production started in December 2010. All ten of the C100 cryomodules are installed in the linac tunnels and are on schedule to complete commissioning by September 2013. Performance during Commissioning has ranged from 104 MV to 118 MV. In May, 2012 a test of an early C100 achieved 108 MV with full beam loading. This paper will discuss the performance of the C100 cryomodules along with operational challenges and lessons learned for future designs.
Download or read book Proceedings of the 28th International Cryogenic Engineering Conference and International Cryogenic Materials Conference 2022 written by Limin Qiu and published by Springer Nature. This book was released on 2023-11-01 with total page 1176 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers selected papers from the 28th International Cryogenic Engineering Conference and International Cryogenic Materials Conference 2022 (ICEC28-ICMC 2022), held virtually in Hangzhou, China on 25-29 April 2022, due to COVID-19 pandemic. Highlighting the latest findings on cryogenic engineering and cryogenic materials, it covers topics including: large-scale cryogenic components, processes and systems for refrigeration, separation, and liquefaction of cryogenic fluids, small-scale cryocoolers, cryogenic space applications, thermal insulation, thermal-physical properties of cryogenic fluids and materials, superconducting materials, devices, systems and applications, etc. The book offers valuable information and insights for academic researchers, engineers in the industry, and operators in the cryogenic field.
Download or read book Proposal for the Cryogenic Supply of a Single TTF FEL cryomodule Test Bench written by Wolf-Dietrich Moeller and published by . This book was released on 2001 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book SNS Cryomodule Performance written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thomas Jefferson National Accelerating Facility, Jefferson Lab, is producing 24 Superconducting Radio Frequency (SRF) cryomodules for the Spallation Neutron Source (SNS) cold linac. This includes one medium beta (0.61) prototype, 11 medium beta production, and 12 high beta (0.81) production cryomodules. After testing, the medium beta prototype cryomodule was shipped to Oak Ridge National Laboratory (ORNL) and acceptance check out has been completed. All production orders for cavities and cryomodule components are being received at this time and the medium beta cryomodule production run has started. Each of the medium beta cryomodules is scheduled to undergo complete operational performance testing at Jefferson Laboratory before shipment to ORNL. The performance results of cryomodules to date will be discussed.
Download or read book Performance of the Cebaf Prototype Cryomodule Renascence written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The prototype cryomodule Renascence was constructed as an energy building block for securing 6 GeV operation of CEBAF and to validate design elements for future CEBAF upgrade modules. These elements include the new "HG" and "LL" 7-cell cavity designs and a new tuner design.[1,2] Issues were identified during initial testing in 2005. The module has been reworked to address the issues with thermal stability, component breakage, and tuner motion. In addition, opportunity was taken to employ upgraded cleaning and assembly techniques for the cavity string. The HOM coupler heating issue was resolved, and seven of the eight cavities in the cryomodule have run stably at an average of 20 MV/m CW. The cryogenic, rf, and mechanical performance of the cryomodule are presented. Commissioning in CEBAF has just been completed in October 2007.
Download or read book Overview of SNS Cryomodule Performance written by and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thomas Jefferson National Accelerating Facility (Jefferson Lab) has completed production of 24 Superconducting Radio Frequency (SRF) cryomodules for the Spallation Neutron Source (SNS) superconducting linac. This includes one medium-[beta] (0.61) prototype, eleven medium-[beta] and twelve high-[beta] (0.81) production cryomodules. Nine medium-[beta] cryomodules as well as two high-[beta] cryomodules have undergone complete operational performance testing in the Cryomodule Test Facility at Jefferson Lab. The set of tests includes measurements of maximum gradient, unloaded Q (Q0), microphonics, and response to Lorentz forces. The Q{sub ext}'s of the various couplers are measured and the behavior of the higher order mode couplers is examined. The mechanical and piezo tuners are also characterized. The results of these performance tests will be discussed in this paper.
