Download or read book Testing of HOM Coupler Designs on a Single Cell Niobium Cavity written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coaxial higher order mode (HOM) couplers were developed initially for HERA cavities and subsequently for TESLA cavities. They were adopted later for SNS and Jlab upgrade cavities. The principle of operation is the rejection of the fundamental mode by the tunable filter and the transmission of the HOMs. It has been recognized recently that for continuous wave or high duty factor applications of the TESLA coupler the output pick-up probe must stay superconducting in order to avoid its heating by the fundamental mode residual magnetic field leading to deterioration of the cavity quality factor. In addition, the thermal conduction of existing rf feedthrough designs is only marginally sufficient to keep even the niobium probe tip superconducting in cw operation. We have equipped a single-cell niobium cavity with the modified HOM couplers and tested the new designs by measuring Q vs Eacc behavior at 2 K for different feedthroughs and probe tip materials.
Download or read book Coaxial HOM Coupler Designs Tested on a Single Cell Niobium Cavity written by Peter Kneisel and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Coaxial higher order mode (HOM) couplers have been developed for HERA cavities and are used in TESLA, SNS and JLab upgrade cavities. The principle of operation is the rejection of the fundamental mode by the tunable filter of the coupler and the transmission of the HOMs. It has been recognized recently that inappropriate thermal designs of the feedthrough for the pick-up probe of the HOM coupler will not sufficiently carry away the heat generated in the probe tip by the fundamental mode fields, causing a built-up of the heating of the niobium probe tip and subsequently, a deterioration of the cavity quality factor has been observed in CW operation. An improvement of the situation has been realized by a better thermal design of the feedthrough incorporating a sapphire rf window [1]. An alternative is a modification of the coupler loop (?F?? part) with an extension towards the pick-up probe. This design has been tested on a single cell niobium cavity in comparison to a ''standard TESLA'' configuration by measuring the Eacc behavior at 2 K. The measurements clearly indicate that the modified version of the coupler loop is thermally much more stable than the standard version.
Download or read book COAXIAL HOM COUPLER DESIGNS TESTED ON A SINGLE CELL NIOBIUM CAVITY written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Poster - Coaxial higher order mode (HOM) couplers have been developed for HERA cavities and are used in TESLA, SNS and JLab upgrade cavities. The principle of operation is the rejection of the fundamental mode by the tunable filter of the coupler and the transmission of the HOMs. It has been recognized recently that inappropriate thermal designs of the feed through for the pick-up probe of the HOM coupler will not sufficiently carry away the heat generated in the probe tip by the fundamental mode fields, causing a built-up of the heating of the niobium probe tip and subsequently, a deterioration of the cavity quality factor has been observed in CW operation. An improvement of the situation has been realized by a better thermal design of the feed through incorporating a sapphire rf window. An alternative is a modification of the coupler loop (?F?? part) with an extension towards the pick-up probe. This design has been tested on a single cell niobium cavity in comparison to a 'standard TESLA' configuration by measuring the Eacc behavior at 2 K. The measurements clearly indicate that the modified version of the coupler loop is thermally much more stable than the standard version.
Download or read book RF Superconductivity written by Hasan Padamsee and published by John Wiley & Sons. This book was released on 2009-03-30 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the second book to RF Superconducting, written by one of the leading experts. The book provides fast and up-to-date access to the latest advances in the key technology for future accelerators. Experts as well as newcomers to the field will benefit from the discussion of progress in the basic science, technology as well as recent and forthcoming applications. Researchers in accelerator physics will also find much that is relevant to their discipline.
Download or read book Design Fabrication and Testing of Superconducting RF Cavities for High Average Beam Currents written by David Joseph Meidlinger and published by . This book was released on 2007 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of the Superconducting 3 9 GHz Accelerating Cavity at Fermilab written by H. Carter and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: A superconducting third harmonic 3.9 GHz accelerating cavity was proposed to improve the beam quality in the TTF-like photoinjector [1]. Fermilab has developed, built and tested several prototypes, including two copper 9-cell cavities, one niobium 3-cell cavity, and one 9-cell cavity. The helium vessel and frequency tuner for the 9-cell cavity was built and tested as well. In cold tests, we achieved a peak surface magnetic field of {approx}100mT, well above the 70mT specification. The accelerating gradient was likely limited by thermal breakdown. Studies of the higher order modes in the cavity revealed that the existing cavity design with two HOM couplers will provide sufficient damping of these modes. In this paper we discuss the cavity design, results of the studies and plans for further development.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993 with total page 762 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiannual, with semiannual and annual indexes. References to all scientific and technical literature coming from DOE, its laboratories, energy centers, and contractors. Includes all works deriving from DOE, other related government-sponsored information, and foreign nonnuclear information. Arranged under 39 categories, e.g., Biomedical sciences, basic studies; Biomedical sciences, applied studies; Health and safety; and Fusion energy. Entry gives bibliographical information and abstract. Corporate, author, subject, report number indexes.
Download or read book Proceedings of the 1987 IEEE Particle Accelerator Conference written by Eric R. Lindstrom and published by . This book was released on 1987 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Results from Prototype Niobium Cavities for The JLab Ampere Class FEL written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous paper the cavity [1] design for an Ampere-class cryomodule was introduced. We have since fabricated a 1500 MHz version of a single cell cavity with waveguide couplers for HOM and fundamental power, attached to one end of the cavity, a 5-cell cavity made from large grain niobium without couplers and. a 750 MHz single cell cavity without endgroups to get some information about obtainable Q-values, gradients and multipacting behavior at lower frequency. This contribution reports on the various tests of these cavities.
Download or read book EPAC 92 written by H. Henke and published by Atlantica Séguier Frontières. This book was released on 1992 with total page 910 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book LHC Design Report written by and published by . This book was released on 2004 with total page 560 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superconducting Prototype Cavities for the Spallation Neutron Source SNS Project written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source project includes a superconducting linac section in the energy range from 186 MeV to 1000 MeV. For this energy range two types of cavities are needed with geometrical [beta] values of [beta] = 0.61 and [beta] = 0.81. An aggressive cavity prototyping program is being pursued at Jefferson Lab, which calls for fabricating and testing four [beta] = 0.61 cavities and two [beta] = 0.81 cavities. Both types consist of six cells made from high purity niobium and feature one HOM coupler on each beam pipe and a port for a high power coaxial input coupler. Three of the four [beta] = 0.61 cavities will be used for a cryomodule test in early 2002. At this time four medium beta cavities and one high beta cavity have been completed at JLab. The first tests on the [beta] = 0.61 and [beta] = 0.81 exceeded the design values for gradient and Q value: E[sub acc] = 10.1 MV/m and Q = 5 x 10[sup 9] at 2.1K for the [beta] = 0.61 and E[sub acc] = 12.3 MV/m and Q = 5 x 10[sup 9] at 2.1 K for the [beta] = 0.81. One of the medium beta cavities has been equipped with an integrated helium vessel and measurements of the static Lorentz force detuning have been done and compared to the ''bare'' cavities. In addition two single cell cavities have been fabricated, equipped with welded-on HOM couplers. They are being used to evaluate the HOM couplers with respect to multipacting, fundamental mode rejection and HOM damping as far as possible in a single cell. This paper describes the cavity design with respect to electromagnetic and mechanical features, the fabrication efforts and the results obtained with the different cavities existing at the time of this workshop.
Download or read book RF Superconductivity for Accelerators written by Hasan Padamsee and published by John Wiley & Sons. This book was released on 2008-02-26 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces some of the key ideas of this exciting field, using a pedagogic approach, and presents a comprehensive overview of the field. It is divided into four parts. The first part introduces the basic concepts of microwave cavities for particle acceleration. The second part is devoted to the observed behavior of superconducting cavities. In the third part,general issues connected with beam-cavity interaction and the related issues for the critical components are covered. The final part discusses applications of superconducting cavities to frontier accelerators of the future, drawing heavily on the examples that are in their most advanced stage. Each part of the book ends in a Problems section to illustrate and amplify text material as well as draw on example applications of superconducting cavities to existing and future accelerators.
Download or read book Advances in Cryogenic Engineering written by Peter Kittel and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 2054 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Oregon Convention Center, Portland, Oregon, was the venue for the 1997 Cryogenic Engineering Conference. The meeting was held jointly with the International Cryogenic Materials Conference. John Barclay, of the University of Victoria, and David Smathers, of Cabot Performance Materials, were conference chairmen. Portland is the home of Northwest Natural Gas, a pioneer in the use of liquid natural gas, and Portland State University, where cryogenic research has long been conducted. The program consisted of 350 CEC papers, considerable more than CEC-95. This was the largest number of papers ever submitted to the CEC. Of these, 263 papers are published here, in Volume 43 of Advances in Cryogenic Engineering. Once again the volume is published in two books. CEC PAPER REVIEW PROCESS Since 1954 Advances in Cryogenic Engineering has been the archival publication of papers presented at the biennial CEC!ICMC conferences. The publication includes invited, unsolicited, and government sponsored research papers in the research areas of cryogenic engineering and applications. All of the papers published must (1) be presented at the conference, (2) pass the peer review process, and (3) report previously unpublished theoretical studies, reviews, or advances in cryogenic engineering.
Download or read book Novel ideas for accelerators particle detection and data challenges at future colliders written by Alessandro Tricoli and published by Frontiers Media SA. This book was released on 2023-07-21 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Brightness Accelerators written by Anthony D. Hyder and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt: A NATO Advanced Study Institute (ASI) on High-Brightness Accelerators was held at the Atholl Palace Hotel, Pitlochry, Perthshire, Scotland, from July 13 through July 25, 1986. This publication is the Proceedings of the Institute. This ASI emphasized the basic physics and engineering of the rela tively new and fast-emerging field of high-brightness particle accelera tors. These machines are high- to very-high-current (amperes to hundreds of kiloamperes), modest-voltage (megavolt to tens of megavolts) devices, and as such are opposed to those historically used for high-energy physics studies (i.e., gigavolt and higher energies and rather low currents). The primary focus of the Institute was on the physics of the accelerator and the beam, including the dynamics, equilibria, and insta bilities of high-current beams near the space-charge limit; accelerator engineering techniques; and the applications of high-brightness beams in areas such as free-electron lasers, synchrotron-radiation sources, food processing, and heavy- and light-ion fusion. The Institute concentrated on bringing together several diverse but related communities which, we hope, benefited from this opportunity to interact: the North American activity in machine technology, engineer ing, and diagnostics with the strong European theoretical community; the basic beam physicists with the engineering technologists.
Download or read book Proceedings Of The 28th International Conference On High Energy Physics In 2 Volumes written by Zygmunt Ajduk and published by World Scientific. This book was released on 1997-04-11 with total page 1878 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 28th conference from the Rochester series was the major high energy physics conference in 1996. Volume one contains short reports on new theoretical and experimental results. Volume two consists of the review talks presented in the plenary sessions.
