Download or read book Electron cloud Mitigation in the Spallation Neutron Source Ring written by P. Cameron and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H- injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation.
Download or read book Electron Cloud Mitigation in the Spallation Neutron Source Ring written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Spallation Neutron Source (SNS) accumulator ring is designed to accumulate, via H− injection, protons of 2 MW beam power at 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. At such beam intensity, electron-cloud is expected to be one of the intensity-limiting mechanisms that complicate ring operations. This paper summarizes mitigation strategy adopted in the design, both in suppressing electron-cloud formation and in enhancing Landau damping, including tapered magnetic field and monitoring system for the collection of stripped electrons at injection, TiN coated beam chamber for suppression of the secondary yield, clearing electrodes dedicated for the injection region and parasitic on BPMs around the ring, solenoid windings in the collimation region, and planning of vacuum systems for beam scrubbing upon operation.
Download or read book Mitigation of the Electron cloud Effect in the PSR and SNS Proton Storage Rings by Tailoring the Bunch Profile written by and published by . This book was released on 2003 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and for the Proton Storage Ring (PSR) at Los Alamos, both with intense and very long bunches, the electroncloud develops primarily by the mechanism of trailing-edge multipacting. We show, by means of simulations for the PSR, how the resonant nature of this mechanism may be effectively broken by tailoring the longitudinal bunch profile at fixed bunch charge, resulting in a significant decrease in the electron-cloud effect. We briefly discuss the experimental difficulties expected in the implementation of this cure.
Download or read book 75 F nfundsiebzig Jahre SVB written by and published by . This book was released on 1977 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ELECTRON CLOUD AT COLLIMATOR AND INJECTION REGION OF THE SPALLATION NEUTRON SOURCE ACCUMULATOR RING written by and published by . This book was released on 2005 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The beam loss along the Spallation Neutron Source's accumulator ring is mainly located at the collimator region and injection region. This paper studied the electron cloud build-up at these two regions with the three-dimension program CLOUDLAND.
Download or read book Electron Cloud Development in the Proton Storage Ring and in TheSpallation Neutron Source written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We have applied our simulation code "POSINST" to evaluatethe contribution to the growth rate of the electron-cloud instability inproton storage rings. Recent simulation results for the main features ofthe electron cloud in the storage ring of the Spallation Neutron Source(SNS) at Oak Ridge, and updated results for the Proton Storage Ring (PSR)at Los Alamos are presented in this paper. A key ingredient in our modelis a detailed description of the secondary emitted-electron energyspectrum. A refined model for the secondary emission process includingthe so-called true secondary, rediffused and backscattered electrons hasrecently been included in the electron-cloud code.
Download or read book Electron Cloud Instabilities in the Proton Storage Ring AndSpallation Neutron Source written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electron cloud instabilities in the Los Alamos ProtonStorage Ring (PSR) and those foreseen forthe Oak Ridge SpallationNeutron Source (SNS) are examined theoretically, numerically, andexperimentally.
Download or read book Collective Effects and Their Control at the Spallation Neutron Source Ring written by and published by . This book was released on 2002 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The SNS ring is designed to accumulate up to 2 x 1014 protons of 1 GeV kinetic energy at a repetition rate of 60 Hz [1]. Dominant collective effects include space charge and halo generation, impedance-driven instabilities, impedance-induced closed-orbit deviation and heating, and electron cloud.
Download or read book Reviews Of Accelerator Science And Technology Volume 6 Accelerators For High Intensity Beams written by Alexander Wu Chao and published by World Scientific. This book was released on 2014-04-01 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: As particle accelerators strive forever increasing performance, high intensity particle beams become one of the critical demands requested across the board by a majority of accelerator users (proton, electron and ion) and for most applications. Much effort has been made by our community to pursue high intensity accelerator performance on a number of fronts. Recognizing its importance, we devote this volume to Accelerators for High Intensity Beams. High intensity accelerators have become a frontier and a network for innovation. They are responsible for many scientific discoveries and technological breakthroughs that have changed our way of life, often taken for granted. A wide range of topics is covered in the fourteen articles in this volume.
Download or read book Exploration of Equal Tune Transverse Coupling in the Spallation Neutron Source Accumulator Ring written by Robert Edward Potts and published by . This book was released on 2017 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of hadron machines is one of the main areas of focus in accelerator technology and is specifically called out as a priority in the high energy physics 10-year plan[70]. The trend for future accelerators is to move towards very high-intensity high-power accelerators to be used as proton drivers for secondary particles, target stations, and high-energy accelerators. These accelerators require lower beam losses and more stringent beam controls to maintain typical loss levels and meet specific final beam distributions. This study focuses on the recently documented coupling resonance in the Spallation Neutron Source (SNS) accumulator ring. It was previously demonstrated that certain beam configurations resulted in a loss of independent control of the on-target transverse beam profiles[12]. This is an issue for SNS production operations. Yet there has not been a robust experimental exploration of the coupling resonance aimed at understanding the effect on the evolution of the beam distribution. The SNS is an ideal facility for this exploration. We studied the coupling experimentally using traditional wire scanners and a novel Electron Scanner. We demonstrated coupling in both the RMS size and beam profile that was correlated with the tune split. The coupling started at low intensity and had an inverse relationship with intensity; indicating that it is not a Montague resonance. We modeled one experiment using a realistic self-consistent particle-in-cell simulation in PyORBIT. We demonstrated strong coupling that was very sensitivity to the tune split. By comparing fringe field models, we demonstrated that fringe fields are the source of the resonance. Our final experiment focused on mitigating the effects during operations. We used the Electron Scanner to demonstrate that the most recent production settings produced no coupling. Further mitigation of the resonance should not be necessary, provided that the tunes remain split. Additionally, we calibrated the newly installed Electron Scanner by measuring the undeflected electron beam, the Twiss parameters, and establishing a benchmark with the wire scanner emittance station. In conclusion, this dissertation constitutes a significant advancement to the overall knowledge of equal tune resonances in circular particle accelerators, especially the effect on the beam profiles.
Download or read book Proceedings Ecloud 04 written by and published by . This book was released on 2005 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ECLOUD 02 written by Giovanni Rumolo and published by . This book was released on 2002 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book HIGH INTENSITY EFFECTS IN THE SNS ACCUMULATOR RING written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently operating at 0.5 MW beam power on target, the Spallation Neutron Source (SNS) is already the world's most powerful pulsed neutron source. However, we are only one third of the way to full power. As we ramp toward full power, the control of the beam and beam loss in the ring will be critical. In addition to practical considerations, such as choice of operating point, painting scheme, RF bunching, and beam scattering, it may be necessary to understand and mitigate collective effects due to space charge, impedances, and electron clouds. At each stage of the power ramp-up, we use all available resources to understand and to minimize beam losses. From the standpoint of beam dynamics, the losses observed so far under normal operating conditions have not involved collective phenomena. We are now entering the intensity regime in which this may change. In dedicated high intensity beam studies, we have already observed resistive wall, extraction kicker impedance-driven, and electron cloud activities. The analysis and simulation of this data are important ongoing activities at SNS. This paper discusses the status of this work, as well as other considerations necessary to the successful full power operation of SNS.
Download or read book The Savannah River Accelerator Project And Complementary Spallation Neutron Sources written by Frank T Avignone Iii and published by World Scientific. This book was released on 1998-02-24 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: This proceedings volume is a collection of papers dealing with the applications of spallation neutron sources to pure science, applied science and defense programs. The topics, ranging from accelerator technology to applications in materials science and neutrino physics, are covered by experts in their respective fields.
Download or read book Space Charge Simulations for the Spallation Neutron Source SNS Ring Using Unified Accelerator Libraries written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
