Download or read book Analysis of NSLS II Touschek Lifetime written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As scrapers are adopted for the loss control of NSLS-II storage ring, Touschek lifetime estimations for various cases are required to assure the stable operation. However, to estimate the Touschek lifetime, momentum apertures should be measured all along the ring and, if we want to estimate the lifetime in various situations, it can take extremely long time. Thus, rather than simulating for each case, a semi-analytic methods with the interpolations are used for the measurements of the momentum apertures. In this paper, we described the methods and showed the results. Having enough Touschek lifetime is important for synchrotron light source for the users to perform experiments with stable beams. In NSLS-II, the scrapers will be installed for the loss control. Especially, the horizontal scrapers will be installed where the dispersions are maximum. Therefore, we need to find the proper scraper gap values which do not reduce the lifetime too much for the stable beam operation. To estimate reliable Touschek lifetime, we should measure the momentum apertures at many positions along the ring. For the rough estimation of the Touschek lifetime, the RF momentum acceptance can be used and for a more detailed estimation, the linear approximation of synchrotron oscillation can be used. However, for the strong focussing synchrotrons, like NSLS-II, the linear approximation is not enough to obtain the reliable momentum apertures, and, in general, particle tracking simulations are used. However, for NSLS-II case, we need to track the particle about 400 turns at each point to make it a full synchrotron oscillation period and to obtain the reliable Touschek lifetime we need measure the momentum apertures at several hundred positions at least. Therefore, it can take quite a long time if we want to have the reasonable resolution for the measurements. Furthermore, at the simulation, if we want to measure the aperture inside a element, we should divide the element and this will make the simulation longer. Here, we developed a systematic method to calculate the momentum aperture using interpolation tables. Once the tables are prepared, the precise momentum aperture can be calculated instantly at arbitrary position for various situations.
Download or read book Touschek Lifetime Calculations for NSLS II written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Touschek effect limits the lifetime for NSLS-II. The basic mechanism is Coulomb scattering resulting in a longitudinal momentum outside the momentum aperture. The momentum aperture results from a combination of the initial betatron oscillations after the scatter and the non-linear properties determining the resultant stability. We find that higher order multipole errors may reduce the momentum aperture, particularly for scattered particles with energy loss. The resultant drop in Touschek lifetime is minimized, however, due to less scattering in the dispersive regions. We describe these mechanisms, and present calculations for NSLS-II using a realistic lattice model including damping wigglers and engineering tolerances.
Download or read book Accelerator Physics Challenges for the NSLS II Project written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The NSLS-II is an ultra-bright synchrotron light source based upon a 3-GeV storage ring with a 30-cell (15 super-period) double-bend-achromat lattice with damping wigglers used to lower the emittance below 1 nm. In this paper, we discuss the accelerator physics challenges for the design including: optimization of dynamic aperture; estimation of Touschek lifetime; achievement of required orbit stability; and analysis of ring impedance and collective effects.
Download or read book COLLECTIVE EFFECTS IN THE NSLS II STORAGE RING written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new high-brightness synchrotron light source (NSLS-II) is under design at BNL. The 3-GeV NSLS-II storage ring has a double-bend achromatic lattice with damping wigglers installed in zero-dispersion straights to reduce the emittance below 1nm. In this paper, we present an overview of the impact of collective effects upon the performance of the storage ring. Subjects discussed include instability thresholds, Touschek lifetime and intra-beam scattering.
Download or read book Touschek Lifetime for the NSLS Free Electron Laser Experiment written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The VUV-Ring of the National Synchrotron Light Source is designed to operate at an electron energy of 700 MeV with an average current of 1 Amp distributed in nine bunches. High brightness sources of synchrotron radiation are obtained by a lattice design yielding a small electron beam emittance, the uncoupled value at 700 MeV being 9 X 10-8 m-rad. Recently there has been interest in using the VUV-Ring for an experiment to study the operation of a free electron laser. For this purpose it is necessary to operate at an energy lower than 700 MeV, say 400 or 500 MeV. A consequence of the lower energy is that the emittance will be reduced by a factor of 1/3 or 1/2, respectively, relative to the value at 700 MeV. Since it is the peak current which determines the laser gain, it is hoped to achieve an average current of 1 Amp distributed in three bunches, the length of a bunch being kept as short as possible. The combination of high peak current, small transverse dimensions, and low energy lead one to be concerned about the Touschek lifetime. In this note the Touschek lifetime for the free electron laser experiment is considered. The conclusion is reached that although minimizing the electron emittance is appropriate to optimize the performance of the ring as a synchrotron light source, for the free electron laser it is desirable to operate at a lower tune having a larger emittance. This increases the Touschek lifetime and does not result in any detrimental effects on the laser gain. In fact the match between the electron beam cross section and that of the radiation field in the laser cavity is improved.
Download or read book Low Horizontal Beta Function in Long Straights of the NSLS II Lattice written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 short straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this paper, we explore the possibility of maintaining three long straights with large horizontal beta function while providing the other 12 long straights with smaller horizontal beta function to optimize the brightness of insertion devices. Our study considers the possible linear lattice solutions as well as characterizing the nonlinear dynamics. Results are reported on optimization of dynamic aperture required for good injection efficiency and adequate Touschek lifetime. This paper discusses dynamic aperture optimization for the NSLS-II lattice with alternate high and low horizontal beta function in the long straights, which is proposed for the optimization of the brightness of insertion devices. The linear optics is optimized to meet the requirements of lattice function and source properties. Nonlinear optimization for a lattice with working point at (37.18, 16.2) is performed. Considering the realistic magnets errors and physical apertures, we calculate the frequency maps and plot the tune footprint. The results show that the lattice with high-low beta function has adequate dynamic aperture for good injection efficiency and sufficient Touschek lifetime.
Download or read book Additional Quadrupoles at Center of Long Straights in the NSLS II Lattice written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The NSLS-II storage ring lattice is comprised of 30 DBA cells arranged in 15 superperiods. There are 15 long straight sections (9.3m) for injection, RF and insertion devices and 15 shorter straights (6.6m) for insertion devices. In the baseline lattice, the short straights have small horizontal and vertical beta functions but the long straights have large horizontal beta function optimized for injection. In this paper, we explore the possibility of installing additional quadrupoles at the center of selected long straight sections in order to provide two low-beta source locations for undulators in the same straight. The required modification to the linear lattice is discussed as well as the preservation of adequate dynamic aperture required for good injection efficiency and adequate Touschek lifetime. This paper discusses the possibility of producing two low-beta source locations for optimum brightness of undulators in the long straights of NSLS-II lattice by installing additional quadrupoles at the center. The linear optics is optimized to satisfy the requirements of lattice function and properties. Nonlinear optimization for a lattice with working point at (37.16, 17.22) is performed. Considering the magnets misalignment errors and physical apertures, we calculate the frequency maps and plot the tune footprint. The results show that the modified high-low beta function lattice can achieve a modest dynamic aperture in this preliminary study. Further work will continue to expand the dynamic aperture to meet the requirement of good injection efficiency and sufficient Touschek lifetime.
Download or read book Top Off Safety Analysis for NSLS II written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Top-off injection will be adopted in NSLS-II. To ensure no injected beam can pass into experimental beamlines with open photon shutters during top-off injection, simulation studies for possible machine fault scenarios are required. We compare two available simulation methods, backward (H. Nishimura-LBL) and forward tracking (A. Terebilo-SLAC). We also discuss the tracking settings, fault scenarios, apertures and interlocks considered in the analysis.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1992 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Coupled bunch Instabilities for the NSLS II Storage Ring with a 500MHz 7 cell PETRA III Cavity written by and published by . This book was released on 2015 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the NSLS-II storage ring that is designed to operate with superconducting RF-cavities with the aim to store an average current of 500 mA distributed in 1080 bunches, with a gap in the uniform filling for ion clearing. At the early stage of the commissioning (phase 1), characterized by a bare lattice without damping wigglers and without Landau cavities, a normal conducting 7-cell PETRA-III RF-cavity structure has been installed with the goal to store an average current of 25 mA. In this paper we discuss our analysis of coupled-bunch instabilities driven by the Higher Order Modes (HOMs) of the 7-cell PETRA-III RF-cavity. As a cure of the instabilities, we apply a well-known scheme based on a proper detuning of the HOMs frequencies based upon cavity temperature change, and the use of the beneficial effect of the slow head-tail damping at positive chromaticity to increase the transverse coupled-bunch instability thresholds. In addition, we discuss measurements of coupled-bunch instabilities observed during the phase 1 commissioning of the NSLS-II storage ring. In our analysis we rely, in the longitudinal case, on the theory of coupled-bunch instability for uniform fillings, while in the transverse case we complement our studies with numerical simulations with OASIS, a novel parallel particle tracking code for self-consistent simulations of collective effects driven by short and long-range wakefields.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1980 with total page 1280 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Impedances And Wakes In High Energy Particle Accelerators written by Semyon Kheifets and published by World Scientific. This book was released on 1998-02-28 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern particle accelerators and storage rings, whether used for high-energy physics, synchrotron light sources, or other purposes, require particle beams with the highest possible intensity. In order to achieve this maximum performance, a good understanding of the interaction of the charged particle beams with the surrounding vacuum chamber and other accelerator components is necessary. In the frequency domain, this interaction can be described by impedances, and equivalently by wake fields in the time domain. These need to be known to estimate the thresholds of coherent instabilities, or other collective effects, which limit the achievable beam current. Such considerations have to be taken into account already during the design of such machines, as they limit the choice of materials and the shapes of components required for their operations.The book explains the basic concepts, and the methods which have been used to calculate impedances and wakes. The emphasis is on circular particle accelerators and storage rings, with which the authors are more familiar, but many of these concepts are equally useful in linear accelerators or colliders. Without any pretense of completeness, the most important accelerator components, such as vacuum chambers with bellows and pumping ports, RF and other cavities, single steps, irises and collimators, etc. are described in specialised chapters. Also limitations and restrictions of the impedance and wake field descriptions are discussed. The book is mainly written for physicists working with or on particle accelerators or storage rings, and who want to understand the methods which have been used for such calculations.
Download or read book Brilliant Light in Life and Material Sciences written by Vasili Tsakanov and published by Springer Science & Business Media. This book was released on 2007-03-31 with total page 484 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains an excellent overview of the status and highlights of brilliant light facilities and their applications in biology, chemistry, medicine, materials and environmental sciences. Overview papers on diverse fields of research by leading experts are accompanied by the highlights in the near and long-term perspectives of brilliant X-Ray photon beam usage for fundamental and applied research.
Download or read book Synchrotron Light Sources and Free Electron Lasers written by Eberhard J. Jaeschke and published by Springer. This book was released on 2016-05-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources driven by laser-plasma accelerators. The applications of the most advanced light sources and the advent of nanobeams and fully coherent x-rays allow experiments from which scientists in the past could not even dream. Examples are the diffraction with nanometer resolution, imaging with a full 3D reconstruction of the object from a diffraction pattern, measuring the disorder in liquids with high spatial and temporal resolution. The 20th century was dedicated to the development and improvement of synchrotron light sources with an ever ongoing increase of brilliance. With ultrahigh brilliance sources, the 21st century will be the century of x-ray lasers and their applications. Thus, we are already close to the dream of condensed matter and biophysics: imaging single (macro)molecules and measuring their dynamics on the femtosecond timescale to produce movies with atomic resolution.
Download or read book Physics Briefs written by and published by . This book was released on 1992 with total page 1332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government reports annual index written by and published by . This book was released on 199? with total page 938 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
