Download or read book Status and Early Commissioning Results for the PEP II High Energy Ring written by and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The High Energy Ring of the PEP-II B-Factory has been constructed in the PEP tunnel. It is now beginning beam commissioning. This report will address the status of the ring systems and our experience in commissioning the systems as well as the first beam running.
Download or read book Beam Comissioning of the PEP II High Energy Ring written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The PEP-II High Energy Ring (HER), a 9 GeV electron storage ring, has been in commissioning since spring 1997. Initial beam commissioning activities focused on systems checkout and commissioning and on determining the behavior of the machine systems at high beam currents. This phase culminated with the accumulation of 0.75 A of stored beam-sufficient to achieve design luminosity--in January 1998 after 3.5 months of beam time. Collisions with the 3 GeV positron beam of the Low Energy Ring (LER) were achieved in Summer of 1998. At high beam currents, collective instabilities have been seen. Since then, commissioning activities for the HER have shifted in focus towards characterization of the machine and a rigorous program to understand the machine and the beam dynamics is presently underway.
Download or read book Commissioning the 90 Degree Lattice for the PEP II High Energy Ring written by and published by . This book was released on 2011 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to benefit from further reduction of the vertical IP beta function of the PEP-II high energy ring (HER) the bunch length should be reduced. This will be achieved by changing the phase advance from 60 degree to 90 degree in the four arcs not adjacent to the IR region, thus reducing momentum compaction by about 30% and reducing bunch length from a present 12 mm down to 8.5 mm at low beam current. In preparation to implement the 90 degree lattice the main HER quadrupole and sextupole strings and their power supplies have been reconfigured. The synchrotron tune initially will be lower but can be brought back by raising the rf voltage. Beam emittance is held at 48 nmr by introducing a significant dispersion beat in the arcs. The lattice was successfully commissioned at currents up to 800 mA in August 2007. In this paper we will compare the actual machine with the predicted behaviour, explain the correction strategies used and give an overall assessment of the operation and the benefit of the new lattice configuration.
Download or read book Lattice Performance of the PEP II High Energy Ring written by and published by . This book was released on 1998 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: The High Energy Ring (HER) of PEP-II, an asymmetric B-factory, has been commissioned since June 1997. By the end of the last run, it has successfully stored the beam up to 300 mA with a beam-life time of a few hours. Its lattice was resilient and behaved remarkably well. Although the authors are still in an early stage of the commissioning, they will assess the status of the lattice quality and identify improvements necessary in the near future by simulating the lattice in a way that is closely related to the operation and comparing the results with the measured data.
Download or read book Status of the PEP II B Factory High Energy Ring written by and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 9 GeV High Energy Ring (HER) of the PEP-II B Factory is an electron storage ring under construction at SLAC. Significant progress has been made in the last year on all systems. As of mid 1996, all 192 dipoles have been installed, with installation of the quadrupoles underway. The vacuum system, for design currents up to 3 A average, is in production using a recently commissioned e-beam welder. Beam instrumentation systems are being fabricated. The interaction region will bring the HER beam into collision with the 3 GeV beam of the Low Energy Ring; design of this section of the HER is in an advanced stage.
Download or read book Commissioning the Beam Diagnostics for the PEP II B Factory written by and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: PEP-II is a 2.2-km-circumference collider with a 2.1-A, 3.1-GeV positron ring (the Low-Energy Ring) 1 m above a 1-A, 9-GeV electron ring (the High-Energy Ring); both rings are designed for a maximum current of 3 A. The authors describe the beam diagnostics and present measurements from HER commissioning. The beam profile is measured using near-UV synchrotron light extracted by grazing-incidence mirrors that must withstand up to 200 W/cm. Normally 1,658 of the 3,492 buckets will be filled, and the charge must be equal within 2%. To measure the charge in each bucket, the sum signal from a set of 4 pickup buttons is digitized and averaged over 256 samples per bucket in every 60-Hz interval. The sum is them normalized to the ring current, measured by a DC current transformer. The 300 beam-position monitors per ring are multiplexed to share 171 processor modules, which use DPSs for recording positions over 1,024 turns and for calibration. For both diagnostics and machine protection, 100 photomultipliers with fused-silica Cherenkov radiators measure beam losses and can trigger a beam abort in case of high loss. For the ring tunes, signals from a set of 4 pickup buttons are combined into horizontal, vertical, and sum signals. Two signals are selected and downconverted into the range of a 10-MHz, 2-channel, programmable, DSP-based spectrum analyzer, connected over ethernet to the control room.
Download or read book PEP II Status Report written by and published by . This book was released on 1998 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main design features of the PEP-II asymmetric two-ring electron-positron B Factory collider, built at the Stanford Linear Accelerator Center, are described. This facility will complete construction in June 1998. The high energy ring, completed in May 1997, has had 3 months of commissioning and successfully stored 0.75 A of electrons. The success of the high energy ring testing validates not only its ring components, but also the injection system, the RF system and the control system all of which are common to the two rings.
Download or read book Commissioning of the PEP II High Power RF Systems written by and published by . This book was released on 1998 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: The authors describe the commissioning of the high-power RF stations for the PEP-II B factory. This includes in-situ testing and conditioning of components after installation, phasing of cavities within each station and between stations in each ring, capture of first beam, stored-beam operation at low- and moderate-current, commissioning of feedback loops, and high-current operation. Performance of the overall system and of critical components such as klystrons, cavities, windows, tuners and the HOM suppression scheme is reported. Observation of beam motion and signals in the cavity and HOM loads suggest that the HOM impedance reduction necessary for high-current operation has been achieved.
Download or read book PEP II Alignment written by and published by . This book was released on 2003 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The PEP-II Asymmetric B-factory consists of two independent storage rings, one located atop the other in the 2200m-circumference PEP tunnel. The high-energy ring, which stores a 9-GeV electron beam, is an upgrade of the existing PEP collider. It re-utilizes all of the PEP magnets and incorporates a state-of-the-art copper vacuum chamber and a new RF system capable of supporting a one-amp stored beam. The low-energy ring, which stores 3.1-GeV positrons, is new construction. Injection is achieved by extracting electrons and positrons at collision energies from the SLC and transporting them each in a dedicated bypass line. The low-emittance SLC beams will be used for the injection process.
Download or read book The PEP II Project written by Michael S. Zisman and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We describe the present status of the PEP-II project. The project comprises four major systems: Injector, High-Energy Ring (HER), Low-Energy Ring (LER), and Interaction Region (IR). We focus in detail on the design of the LER, as its parameters and requirements are most closely related to those required for the Beijing Tau-Charm Factory rings. The PEP-II LER is a high-current, 3.1-GeV positron ring mounted above the 9-GeV HER. The LER uses a wiggler located in one of its six straight sections to provide emittance control and additional damping. We describe the rather complicated IR, which must transport the LER beam into the plane of the HER, focus it to a common beam size, and separate the beams after the head-on collisions. Both permanent magnet and conventional electromagnets are used in this area. The LER lattice has now adopted a simplified non-interleaved sextupole correction scheme that has reduced the required number of sextupoles substantially. We describe the LER vacuum system, one of the most challenging subsystems in PEP-II. It employs several technologies. In the arcs, aluminum extrusions and titanium sublimation pumps are employed; the straight sections use stainless steel chambers with lumped ion pumps. In the wiggler area, an extended copper photon dump with nonevaporable getter (NEG) pumps is employed to handle the very large synchrotron radiation power. The design of the room-temperature RF system, the bunch-by-bunch longitudinal and transverse feedback systems, and some of the special diagnostics will be described briefly. The PEP-II project remains on schedule to begin commissioning of the HER in April 1997, followed by the LER a year later.
Download or read book LUMINOSITY UPGRADE POSSIBILITIES FOR THE PEP II B FACTORY written by and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: PEP-II is an asymmetric ee− collider being constructed in the SLAC PEP tunnel by SLAC, LBNL, and LLNL. The two beams have energies of 3.1 GeV and 9.0 GeV and are made to collide at a single interaction point. PEP-II has a 2200 m circumference. The nominal parameters for PEP-II are listed in Table 1. The High Energy Ring (HER) of PEP-II started commissioning in 1997. The Low Energy Ring (LER) will be commissioned in the summer of 1998. The BaBar detector is to be installed starting January 1999. Studies for increasing the luminosity in PEP-II beyond the design are underway. A brief summary of the possibilities are presented here. Improvements to the integrated luminosity will be implemented gradually. Major luminosity improvements will likely come in two phased upgrades. Several of these possibilities are summarized in Table 1.
Download or read book Measurement and Control of Charged Particle Beams written by Michiko G. Minty and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the reviews: "This book is a very welcome and valuable addition to the accelerator literature. As noted by the authors, there is relatively little material in the book specifically for low-energy machines, but industrial users may still find it useful to read." Cern Courier
Download or read book The Role of the Social Partners in Vocational Training and Further Training in the Federal Republic of Germany written by Wolfgang Streeck and published by . This book was released on 1987 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Line written by and published by . This book was released on 1998 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Beam Measurement Proceedings Of The Joint Us cern japan russia School On Particle Accelerators written by Stuart Turner and published by World Scientific. This book was released on 1999-05-31 with total page 739 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume comprises the proceedings of the 8th Joint School on accelerator physics. On this occasion, the US, CERN, Japan and Russia Particle Accelerator Schools collaborated to present the topic of “Beam Measurements”. The aim was to provide an introduction to the principles of beam dynamics and measurements in circular particle accelerators. This was achieved by a series of lectures under the headings of “single-particle dynamics”, “multi-particle dynamics” and then “beam measurements”, along with practical courses on feedback and signal processing, maps and (no) simulations, practical diagnostic measurements, and spectrum and network analyzers. The resulting proceedings represent a unique summary of the currently available knowledge on beam measurements applied to circular particle accelerators.
