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Fiducialization Of Superconducting Radio Frequency Cryomodules At Jefferson Lab
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Book Synopsis Fiducialization of Superconducting Radio Frequency Cryomodules at Jefferson Lab by : C. J. Curtis
Download or read book Fiducialization of Superconducting Radio Frequency Cryomodules at Jefferson Lab written by C. J. Curtis and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the early 1990's the Continuous Electron Beam Accelerator Facility (CEBAF), was under construction in Newport News, Virginia. The facility was to be the first of its kind in that it was to provide a continuous beam of electrons for experimental physics at energies of several GeV. One of the key elements of this unique machine was the 338 superconducting radio frequency (SRF) cavities built into 42 cryomodules and arranged in two linacs. These were linked by arcs of conventional magnets which allowed recirculation through the linacs up to five times, in order to achieve the design energy of 4GeV. Within each cryomodule the cavities were aligned and referenced to external fiducials allowing alignment on the design beampath. This paper describes the process developed to achieve this, how it evolved with improving instrumentation, and the results obtained. Suggestions for alternative methods which may prove useful for future projects are also discussed.
Book Synopsis Overview and Lessons Learned of the Jefferson Lab Cryomodule Production for the CEBAF 12 GeV Upgrade by :
Download or read book Overview and Lessons Learned of the Jefferson Lab Cryomodule Production for the CEBAF 12 GeV Upgrade written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab is nearing completion of an energy upgrade from 6 to 12 GeV. An integral part of the upgrade is the addition of ten new cryomodules, each consisting of eight seven-cell superconducting radio-frequency (SRF) cavities. An average performance of 100+MV of acceleration per cryomodule is needed to achieve the 12 GeV beam energy goal. The production methodology was for industry to provide and deliver the major components to Jefferson Lab, where they were tested and assembled into cryomodules. The production process begins with an inspection upon receiving of all major components followed by individual performance qualification testing. The SRF cavities received their final chemical processing and cleaning at Jefferson Lab. The qualified components along with all associated hardware and instrumentation are assembled, tested, installed into CEBAF and run through an integrated system checkout in preparation for beam operations. The production process is complete and one of the first completed cryomodules has successfully produced 108 MV of acceleration with a linac beam current of 465?A.
Book Synopsis Jefferson Lab IR FEL Cryomodule Modifications and Test Results by :
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 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.
Book Synopsis Overview of SNS Cryomodule Performance by :
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.
Book Synopsis Performance of the FEL Cryomodules by :
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.
Book Synopsis JLab CW Cryomodules for 4th Generation Light Sources by :
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 סגולת ישראל written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Superconducting Radio Frequency Technology-understanding and Improvements of Limitations Through Application of Cryogenic Instrumentation by : Peter Kneisel
Download or read book Superconducting Radio Frequency Technology-understanding and Improvements of Limitations Through Application of Cryogenic Instrumentation written by Peter Kneisel and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Results of Cavity Series Fabrication at Jefferson Laboratory for the Cryomodule "R100." by :
Download or read book Results of Cavity Series Fabrication at Jefferson Laboratory for the Cryomodule "R100." written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A series production of eight superconducting RF cavities for the cryomodule R100 was conducted at JLab in 2010. The cavities underwent chemical post-processing prior to vertical high power testing and routinely exceeded the envisaged performance specifications. After cryomodule assembly, cavities were successfully high power acceptance tested. In this paper, we present the achievements paving the way for the first demonstration of 100 MV (and beyond) in a single cryomodule to be operated at CEBAF.
Book Synopsis Upgrade to Cryomodule Test Facility at Jefferson Lab by :
Download or read book Upgrade to Cryomodule Test Facility at Jefferson Lab written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The cryomodule test facility (CMTF) was originally implemented in the late eighties for testing of a small fraction of the cryomodules during the production run for the Continuous Electron Beam Accelerator Facility [1]. The original system was built using a dedicated wiring scheme and a pair of 2 kW, 1497 MHz RF sources. This dedicated system made it difficult to test cryomodules and other RF structures of non-standard configuration. Additionally, due to a previously installed cyclotron, there were static magnetic fields in excess of 6 Gauss within the test cave, which limited the capability of the facility when measuring the quality factor of superconducting cavities. Testing of the Spallation Neutron Source cryomodules as well as future upgrades to the CEBAF accelerator necessitated that the facility be reconfigured to be flexible both with respect to RF source power and cryomodule wiring configuration. This paper will describe the implementation of a generalized wiring scheme t hat is easily adapted to different cryomodule configurations. It will also describe the capabilities of the LabView based low level RF controls and the related data acquisition systems currently being used to test cryomodules and related hardware. The high power RF source capabilities will be described. The magnetic shielding put in place in order to reduce the ambient magnetic file to levels below 50 mGauss will also be described.
Book Synopsis Thermal Optimization in Srf Cryomodule Production by : James Takacs
Download or read book Thermal Optimization in Srf Cryomodule Production written by James Takacs and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconducting Radio Frequency (SRF) cavities are becoming the preferred method of particle acceleration for many new high energy physics projects around the world. These SRF cavities are assembled, in series, into a thermal structure known as a cryomodule (CM). Currently, Thomas Jefferson National Accelerator Facility (JLab) is providing the superconducting cryomodules for both the Spallation Neutron Source (SNS) and the prototype for the energy upgrade to the JLab Continuous Electron Beam Accelerator Facility (CEBAF). Once completed, the cryomodules are assembled in series to form a superconducting linear accelerator (LINAC) utilized primarily for particle physics research and development. During operation, the cryomodule maintains the temperature of the cavities at 2K, while the external shell of the cryomodule is at ambient temperature (293K). This paper will present the design, fabrication and assembly of the CM components in order to optimize thermal performance, which is vital to the SRF cavity operation. This thermal optimization will include both static & dynamic heat load considerations as well as design and assembly techniques.
Book Synopsis Operating Experience with Superconducting Cavities at Jefferson Lab by :
Download or read book Operating Experience with Superconducting Cavities at Jefferson Lab written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The CEBAF recirculating superconducting electron linac at Jefferson Lab is now in full operation supporting nuclear physics experiments in three target halls at up to 4.4 GeV. The 330 SRF cavities, operating at 2.0 K, continue to perform well above design specifications, and have accumulated over 8,000,000 operating cavity hours. The authors have to date no evidence of degradation of cavity performance. The SRF cavities have demonstrated excellent reliability. The one klystron per cavity design provides CEBAF with flexibility and redundancy for normal operations. Several techniques have been developed for establishing optimum operating conditions for the 330 independent systems. Operation of the cavities and control systems at the full design current of 1 mA has recently been achieved. The principal constraints on usable gradient for low current operations are (1) discharge at the cold ceramic rf window induced by electron field emission in cavities, (2) tuner controls, and (3) stability of the waveguide vacuum in the region between the warm and cold windows. Several cryomodules have been improved by application of rf helium processing while installed on the beamline.
Book Synopsis Overview and Status of the 12 GeV Cryogenic System Upgrade At Jlab by :
Download or read book Overview and Status of the 12 GeV Cryogenic System Upgrade At Jlab written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the planned Jefferson Laboratory's electron accelerator (CEBAF) power upgrade, ten additional superconducting RF cryomodules will be added to its accelerator linacs. Although physically the same size as each of the original 40 linac cryomodules, each new cryomodule will have approximately 4 times the acceleration power. To support the additional cryomodule heat loads generated, the existing 2K, 4600W Central Helium Liquefier (CHL) plant capacity will be doubled to a total of 9200W at 2K plus 24,000W at 35K for shield loads. The specified base line process cycle has been modeled after the laboratory s "Ganni Helium Cycle" process technology. In addition, a fourth physics experimental "Hall D" will be constructed which will have an additional stand alone 200W at 4K helium cryogenic plant. In October of 2008, Jefferson Laboratory (JLab) received approval for project "Critical Decision 3" construction phase status from the US Department of Energy.
Book Synopsis Operating Experience with Superconducting Cavities at Jefferson Lab by : Charles Reece
Download or read book Operating Experience with Superconducting Cavities at Jefferson Lab written by Charles Reece and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis A Survey of Pressure Vessel Code Compliance for Superconducting RF Cryomodules by :
Download or read book A Survey of Pressure Vessel Code Compliance for Superconducting RF Cryomodules written by and published by . This book was released on 2011 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superconducting radio frequency (SRF) cavities made from niobium and cooled with liquid helium are becoming key components of many particle accelerators. The helium vessels surrounding the RF cavities, portions of the niobium cavities themselves, and also possibly the vacuum vessels containing these assemblies, generally fall under the scope of local and national pressure vessel codes. In the U.S., Department of Energy rules require national laboratories to follow national consensus pressure vessel standards or to show ''a level of safety greater than or equal to'' that of the applicable standard. Thus, while used for its superconducting properties, niobium ends up being treated as a low-temperature pressure vessel material. Niobium material is not a code listed material and therefore requires the designer to understand the mechanical properties for material used in each pressure vessel fabrication; compliance with pressure vessel codes therefore becomes a problem. This report summarizes the approaches that various institutions have taken in order to bring superconducting RF cryomodules into compliance with pressure vessel codes. In Japan, Germany, and the U.S., institutions building superconducting RF cavities integrated in helium vessels or procuring them from vendors have had to deal with pressure vessel requirements being applied to SRF vessels, including the niobium and niobium-titanium components of the vessels. While niobium is not an approved pressure vessel material, data from tests of material samples provide information to set allowable stresses. By means of procedures which include adherence to code welding procedures, maintaining material and fabrication records, and detailed analyses of peak stresses in the vessels, or treatment of the vacuum vessel as the pressure boundary, research laboratories around the world have found methods to demonstrate and document a level of safety equivalent to the applicable pressure vessel codes.
Book Synopsis Development of a Cryomodule for the CEBAF Upgrade by :
Download or read book Development of a Cryomodule for the CEBAF Upgrade written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Long-term plans for the CEBAF at Jefferson Lab call for achieving 12 GeV in the middle of the next decade and 24 GeV after 2010. In support of those plans, an Upgrade Cryomodule, capable of providing more than three times the voltage of the original CEBAF cryomodule specification within the same length, is under development. In particular, this requires the development of superconducting cavities capable of consistently operating at gradients above 12 MV/m and Q(approximately)101°, new frequency tuners with excellent resolution, and cavity control systems.
