Download or read book Rf Control at Transient Beamloading for High duty factor Linacs written by Michael A. Chernogubovsky and published by . This book was released on 1998 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book RF System Considerations for Large High duty factor Linacs written by and published by . This book was released on 1994 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: RF systems are often a major cost item for linacs, but this is especially true for large high-duty-factor linacs (up to and including CW) such as the Accelerator for Production of Tritium (APT) or the Accelerator for Transmutation of nuclear Waste (ATW). In addition, the high energy and high average beam current of these machines (approximately 1 GeV, 100--200 mA) leads to a need for excellent control of the accelerating fields in order to minimize the possibility of beam loss in the accelerator and the resulting activation. This paper will address the key considerations and limitations in the design of the RF system. These considerations impact the design of both the high power RF components and the RF controls. As might be expected, the two concerns sometimes lead to conflicting design requirements. For example minimum RF operating costs lead to a desire for operation near saturation of the high power RF generators in order to maximize the operating efficiency. Optimal control of the RF fields leads to a desire for maximum overdrive capability in those same generators in order to respond quickly to disturbances of the accelerator fields.
Download or read book Transient Beam Loading Effects in RF Systems in Jleic written by and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The pulsed electron bunch trains generated from the Continuous Electron Beam Accelerator Facility (CEBAF) linac to inject into the proposed Jefferson Lab Electron Ion Collider (JLEIC) e-ring will produce transient beam loading effects in the Superconducting Radio Frequency (SRF) systems that, if not mitigated, could cause unacceptably large beam energy deviation in the injection capture, or exceed the energy acceptance of CEBAF's recirculating arcs. In the electron storage ring, the beam abort or ion clearing gaps or uneven bucket filling can cause large beam phase transients in the (S)RF cavity control systems and even beam loss due to Robinson instability. We have first analysed the beam stability criteria in steady state and estimated the transient effect in Feedforward and Feedback RF controls. Initial analytical models for these effects are shown for the design of the JLEIC e-ring from 3GeV to 12GeV.
Download or read book Transient Beam Loading in the ALS Harmonic RF System written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report on the commissioning of a higher harmonicradiofrequency system at the Advanced Light Source, designed to improvethe beam lifetime. We have achieved an increase above a factor of two inour best results up to now. Transient beam loading of the harmoniccavities, due to the unequal fill patterns, creates the greatestlimitation on lifetime improvement. We also describe several interestingeffects on the operation of the longitudinal and transverse multibunchfeedback system.
Download or read book Optimizing Cavity Gradients in Pulsed Linacs Using the Cavity Transient Response written by and published by . This book was released on 2008 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to achieve beam intensity and luminosity requirements, pulsed LINAC accelerators have stringent requirements on the amplitude and phase of RF cavity gradients. The amplitude and phase of the RF cavity gradients under heavy beam loading must be kept constant within a fraction of a % and a fraction of a degree respectively. The current paper develops a theoretical method to calculate RF parameters that optimize cavity gradients in multi cavity RF units under heavy beam loading. The theory is tested with a simulation example.
Download or read book Transient Beam Loading Effects in Gas filled RF Cavities for a Muon Collider written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A gas-filled RF cavity can be an effective solution for the development of a compact muon ionization cooling channel. One possible problem expected in this type of cavity is the dissipation of significant RF power through the beam-induced plasmas accumulated inside the cavity (plasma loading). In addition, for the higher muon beam intensity, the effects of the beam itself on the cavity accelerating mode are non-negligible (beam loading). These beam- cavity interactions induce a transient phase which may be very harmful to the beam quality [1]. In this study, we estimate the transient voltage in a gas-filled RF cavity with both the plasma and conventional beam loading and discuss their compensation methods.
Download or read book Towards More Efficient Accelerating RF Systems written by Nilanjan Banerjee and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Multi-turn Energy Recovery Linacs (ERLs) powered by Superconducting Radio Frequency (SRF) cavities enable the production of continuous bright high-current beams while being very efficient. The low energy consumption can be attributed to diminishing refrigeration costs from increasingly advanced SRF materials and the efficient use of rf power in maintaining the accelerating gradient. Operating the main linac cavities of SRF ERLs with large QL reduces average rf power consumption but increases its sensitivity to resonance detuning. We discuss passive measures as well as develop a novel Active Noise Control algorithm to reduce microphonics detuning and ensure stable field. This dissertation describes the complete rf commissioning process of a SRF main linac in detail including the use of automation in various steps. These techniques were utilized in the Cornell BNL ERL Test Accelerator (CBETA), the first multi-turn SRF ERL, which achieved an energy recovery efficiency of 99.4 % during high-current operations in the single turn mode. We further analyze the effect of transient beam loading using a novel linear model which predicts the existence of reactive beam loading arising from relativistic effects in the presence of low energy beam. Finally, we discuss a novel thermometry system to image local heating and thermal runaway on the surface of SRF cavities, thus aiding the development of more efficient SRF materials for future ERLs.
Download or read book Operation of the CEBAF Linac with High Beam Loading written by and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The superconducting RF, CW CEBAF accelerator will use a pair of antiparallel 400 MeV linacs connected by recirculation arcs for nominal 4 GeV in five passes. Single-pass, high power testing of the first linac has been conducted during the months preceding the conference. The RF control system [1] has been designed to control cavity gradient and phase under a wide range of gradients and significant beam loading. At full beam current, accelerating gradient is approximately equal to accelerating voltage in the superconducting RF cavities. Even though the beam current during the high power testing is one-fifth of the full current, beam loading is substantial. Operational experience of the response of the RF system is presented. A tuning algorithm which compensates for beam loading effects has been developed and tested. Heavy beam loading, corresponding to five-pass operation, was studied by increasing the loaded Q of the cavities. A current modulation experiment addressed the issue of energy spread increase due to current fluctuations, and the effect of by-passed cavities on beam properties was investigated.
Download or read book Interaction Between Beam Control and Rf Feedback Loops for High Q Cavities an Heavy Beam Loading Revision A written by and published by . This book was released on 1994 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: An open-loop state space model of all the major low-level rf feedback control loops is derived. The model has control and state variables for fast-cycling machines to apply modern multivariable feedback techniques. A condition is derived to know when exactly we can cross the boundaries between time-varying and time-invariant approaches for a fast-cycling machine like the Low Energy Booster (LEB). The conditions are dependent on the Q of the cavity and the rate at which the frequency changes with time. Apart from capturing the time-variant characteristics, the errors in the magnetic field are accounted in the model to study the effects on synchronization with the Medium Energy Booster (MEB). The control model is useful to study the effects on beam control due to heavy beam loading at high intensities, voltage transients just after injection especially due to time-varying voltages, instability thresholds created by the cavity tuning feedback system, cross coupling between feedback loops with and without direct rf feedback etc. As a special case we have shown that the model agrees with the well known Pedersen model derived for the CERN PS booster. As an application of the model we undertook a detailed study of the cross coupling between the loops by considering all of them at once for varying time, Q and beam intensities. A discussion of the method to identify the coupling is shown. At the end a summary of the identified loop interactions is presented.
Download or read book Operating Experience with High Beam Currents and Transient Beam Loading in the SLC Damping Rings written by and published by . This book was released on 1995 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the 1994 SLC run the nominal operating intensity in the damping rings was raised from 3.5 x 101° to greater than 4 x 101° particles per bunch (ppb). Stricter regulation of rf system parameters was required to maintain stability of the rf system and particle beam. Improvements were made in the feedback loops which control the cavity amplitude and loading angles. Compensation for beam loading was also required to prevent klystron saturation during repetition rate changes. To minimize the effects of transient loading on the rf system, the gain of the direct rf feedback loop and the loading angles were optimized.
Download or read book Low level RF System Design for the Next Linear Collider Damping Ring 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 design current for the Next Linear Collider (NLC) damping rings is an order of magnitude higher than existing damping rings. As opposed to storage rings, damping rings are required to operate at a high repetition frequency. Transient beam loading is therefore particularly severe. The NLC design calls for a full current fill pattern consisting of up to 4 trains of 90 bunches for a total dc current of 1.2 A. However, using conventional filling techniques, with a rapid current ramp the ring energy acceptance could decrease due to transient loading and the beam might not be captured. In this paper the authors describe two features of the low-level rf system design. The first avoids any reduction of duty cycle while the second ensures beam capture and regulation of the cavity voltages and beam phase.
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973 with total page 1142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1983 with total page 764 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book RF Linear Accelerators written by Thomas P. Wangler and published by John Wiley & Sons. This book was released on 2008-03-03 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dieses einschlägige Lehrbuch, entwickelt auf der Grundlage der Ausbildung an der US Particle Accelerator School, schließt eine Lücke in der verfügbaren Literatur zum Thema Hochfrequenz-Linearbeschleuniger, kurz RF-Linac. Nach einer Erläuterung der naturwissenschaftlichen Grundlagen und der neuesten technologischen Eckdaten stellt diese zweite Auflage neueste RF-Linacs, spezialisierte Systeme, Systeme mit Supraleitern und verschiedene Spezialverfahren vor. Übungsaufgaben an den Kapitelenden erleichtern das Einprägen und das Nacharbeiten von Vorlesungen.
Download or read book High Energy Physics Index written by and published by . This book was released on 1984 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook Of Accelerator Physics And Engineering Third Edition written by Alexander Wu Chao and published by World Scientific. This book was released on 2023-02-02 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt: Edited by internationally recognized authorities in the field, this expanded and updated new edition of the bestselling Handbook, containing many new articles, is aimed at the design and operation of modern particle accelerators. It is intended as a vade mecum for professional engineers and physicists engaged in these subjects. With a collection of more than 2000 equations, 300 illustrations and 500 graphs and tables, here one will find, in addition to common formulae of previous compilations, hard to find, specialized formulae, recipes and material data pooled from the lifetime experience of many of the world's most able practioners of the art and science of accelerators.The seven chapters include both theoretical and practical matters as well as an extensive glossary of accelerator types. Chapters on beam dynamics and electromagnetic and nuclear interactions deal with linear and nonlinear single particle and collective effects including spin motion, beam-environment, beam-beam, beam-electron, beam-ion and intrabeam interactions. The impedance concept and related calculations are dealt with at length as are the instabilities due to the various interactions mentioned. A chapter on operational considerations including discussions on the assessment and correction of orbit and optics errors, realtime feedbacks, generation of short photon pulses, bunch compression, phase-space exchange, tuning of normal and superconducting linacs, energy recovery linacs, free electron lasers, cryogenic vacuum systems, steady state microbuching, cooling, space-charge compensation, brightness of light sources, collider luminosity optimization and collision schemes, machine learning, multiple frequency rf systems, FEL seeding, ultrafast electron diffraction, and Gamma Factory. Chapters on mechanical and electrical considerations present material data and important aspects of component design including heat transfer and refrigeration. Hardware systems for particle sources, feedback systems, confinement, including undulators, and acceleration (both normal and superconducting) receive detailed treatment in a sub-systems chapter, beam measurement and apparatus being treated therein as well.A detailed name and subject index is provided together with reliable references to the literature where the most detailed information available on all subjects treated can be found.
Download or read book Technical Publications by JAERI Staff in written by Nihon Genshiryoku Kenkyujo and published by . This book was released on 1998 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt:
