Download or read book RF Power and HOM Coupler Tutorial written by B. Rusnak and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Radio frequency (RF) couplers are used on superconducting cavities to deliver RF power for creating accelerating fields and to remove unwanted higher-order mode power for reducing emittance growth and cryogenic load. RF couplers in superconducting applications present a number of interdisciplinary design challenges that need to be addressed, since poor performance in these devices can profoundly impact accelerator operations and the overall success of a major facility. This paper will focus on critical design issues for fundamental and higher order mode (HOM) power couplers, highlight a sampling of reliability-related problems observed in couplers, and discuss some design strategies for improving performance.
Download or read book Design of HOM Coupler Prototype for the APT Superconducting RF Cavities written by and published by . This book was released on 2001 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam dynamics calculations for the Accelerator Production of Tritium (APT) proton linac suggest that wakefields, which are excited during beam operation, would not lead to beam-breakup instabilities. However, in the superconducting (SC) radio-frequency (RF) cavities of the APT linac, higher-order modes (HOMs), whose frequencies are below the beam tube cut-off fiequency, can be sufficiently excited by the beam to add significantly to the heat load removed by the helium refrigerator. In this paper, we present a design of an HOM coupler for the APT RF cavities that will remove this power to a resistive load at room temperature.
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 Comparative Simulation Studies of Multipacting in Higher Order Mode Couplers of Superconducting RF Cavities written by and published by . This book was released on 2014 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6-1.6 MV/m, 21-34 MV/m, 32-35 MV/m, and> 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6-13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MP's predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.
Download or read book Development of Fundamental Power Coupler for High current Superconducting RF Cavity written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.
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 Overview of Recent HOM Coupler Development written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Higher Order Mode (HOM) damping is important for SRF applications, especially for high intensity machines. A good HOM damping design will help to reduce power load to the cryogenic system and to reduce the risk of beam breakup. The design of HOM damping, including antenna/loop HOM couplers, beam pipe HOM absorbers and waveguide HOM couplers, is to solve a multi-physics problem that involves RF, thermal, mechanical, and beam-cavity interaction issues. In this talk, the author provides an overview on the latest advances of the HOM couplers for high intensity SRF applications.
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 Thermal Study of HOM Couplers for Superconducting RF Cavities written by and published by . This book was released on 1993 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book RF Superconductivity for Accelerators written by Hasan Padamsee and published by Wiley-VCH. This book was released on 2008-02-26 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces some of the key ideas of RF Superconductivity by 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 related issues for critical components are covered. The final part discusses applications of superconducting cavities to frontier accelerators of the future, drawing heavily on 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 to draw on example applications of superconducting cavities to existing and future accelerators. FROM THE CONTENTS: * Basics * Performance of Superconducting Cavities * Couplers and Tuners * Frontier Accelerators
Download or read book Fundamental Power Coupler Development for Low beta Superconducting Cavities written by Jon Joseph Wlodarczak and published by . This book was released on 2008 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Accelerator Physics Technology and Applications written by Alex Chao and published by World Scientific. This book was released on 2004 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally invented for generating the first artificial nuclear reactions, particle accelerators have undergone, during the past 80 years, a fascinating development that is an impressive example of the inventiveness and perseverance of scientists and engineers. Since the early 1980s, accelerator science and technology has been booming. Today, accelerators are the prime tool for high energy physics to probe the structure of matter to an unknown depth. They are also, as synchrotron radiation sources, the most versatile tool for characterizing materials and processes and for producing micro- and nanostructured devices. The determination of the structure of large biomolecules is presently among the best examples of the application of synchrotron radiation. Finally, accelerators have grown more and more important for medicine, which is relying on them for advanced cancer therapy and radio-surgery. And there are more applications, including the generation of neutrons for materials science, the transmutation of nuclear waste with simultaneous production of electrical power, the sterilization of medical supplies and of foodstuff, and the inspection of trucks by customs or security services. This book is meant to provide basic training in modern accelerators for students, teachers, and interested scientists and engineers working in other fields. It is a result of the 3rd International Accelerator School, held in 2002 in Singapore under the auspices of the Overseas Chinese Physics Association (OCPA). Reputable experts, including a recent prize-winner, cover the field of cyclic and linear accelerators from the basic theoretical tools to forefront developments such as the X-ray free electron laser or the latest proton therapy facilities under construction. Accelerators, the art of building them, and the science for understanding their function have become a very exciting field of research. This book conveys the excitement of the experts to the reader. The proceedings have been selected for coverage in: . OCo Index to Scientific & Technical Proceedings- (ISTP- / ISI Proceedings). OCo Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings). OCo CC Proceedings OCo Engineering & Physical Sciences."
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 EPAC 90 written by P. Marin and published by Atlantica Séguier Frontières. This book was released on 1990 with total page 1054 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cryogenic Heat Management written by Jonathan Demko and published by CRC Press. This book was released on 2022-07-21 with total page 459 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cryogenic engineering (cryogenics) is the production, preservation, and use or application of cold. This book presents a comprehensive introduction to designing systems to deal with heat – effective management of cold, exploring the directing (or redirecting), promoting, or inhibiting this flow of heat in a practical way. It provides a description of the necessary theory, design methodology, and advanced demonstrations (thermodynamics, heat transfer, thermal insulation, fluid mechanics) for many frequently occurring situations in low-temperature apparatus. This includes systems that are widely used such as superconducting magnets for magnetic resonance imaging (MRI), high-energy physics, fusion, tokamak and free electron laser systems, space launch and exploration, and energy and transportation use of liquid hydrogen, as well as potential future applications of cryo-life sciences and chemical industries. The book is written with the assumption that the reader has an undergraduate understanding of thermodynamics, heat transfer, and fluid mechanics, in addition to the mechanics of materials, material science, and physical chemistry. Cryogenic Heat Management: Technology and Applications for Science and Industry will be a valuable guide for those researching, teaching, or working with low-temperature or cryogenic systems, in addition to postgraduates studying the topic. Key features: Presents simplified but useful and practical equations that can be applied in estimating performance and design of energy-efficient systems in low-temperature systems or cryogenics Contains practical approaches and advanced design materials for insulation, shields/anchors, cryogen vessels/pipes, calorimeters, cryogenic heat switches, cryostats, current leads, and RF couplers Provides a comprehensive introduction to the necessary theory and models needed for solutions to common difficulties and illustrates the engineering examples with more than 300 figures
Download or read book Scientific Assessment of High Power Free Electron Laser Technology written by National Research Council and published by National Academies Press. This book was released on 2009-04-06 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a scientific assessment of free-electron-laser technology for naval applications. The charge from the Office of Naval Research was to assess whether the desired performance capabilities are achievable or whether fundamental limitations will prevent them from being realized. The present study identifies the highest-priority scientific and technical issues that must be resolved along the development path to achieve a megawatt-class free-electron laser. In accordance with the charge, the committee considered (and briefly describes) trade-offs between free-electron lasers and other types of lasers and weapon systems to show the advantages free-electron lasers offer over other types of systems for naval applications as well as their drawbacks. The primary advantages of free-electron lasers are associated with their energy delivery at the speed of light, selectable wavelength, and all-electric nature, while the trade-offs for free-electron lasers are their size, complexity, and relative robustness. Also, Despite the significant technical progress made in the development of high-average-power free-electron lasers, difficult technical challenges remain to be addressed in order to advance from present capability to megawatt-class power levels.
Download or read book Classic Works in RF Engineering written by John L. B. Walker and published by Artech House Publishers. This book was released on 2006 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: The growing interest in commercial RF applications and high-frequency engineering has triggered a scramble for fundamental design and analysis information. This expertly compiled resource gives microwave engineers instant, one-stop access to a vast range of essential source material in a single convenient volume.
