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 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 Instrumentation and Diagnostics written by Peter Strehl and published by Springer Science & Business Media. This book was released on 2006-06-18 with total page 438 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes the experience of many years of teamwork with my group, the beam diagnostics group of GSI. For a long time the group was also responsible for operating the machines and application programming. In my opinion, this connection was very e?cient: ?rst, because a beam diagnostic system has to place powerful tools at the operators’ disposal; second, because data evaluation and presentation of results for machine operation demand application programs which can be handled not only by skilled experts. On the other hand, accelerator developments and improvements as well as commissioning of new machines by specialists require more complex measu- ments than those for routine machine operation. A modern beam diagnostic system, including the software tools, has to cover these demands, too. Therefore, this book should motivate physicists, constructors, electronic engineers, and computer experts to work together during the design and daily use of a beam diagnostic system. This book aims to give them ideas and tools for their work. I would not have been able to write this book without a good education in physics and many discussions with competent leaders, mentors, and c- leagues. After working about 40 years in teams on accelerators, there are so many people I have to thank that it is impossible to mention them all by name here.
Download or read book Beam Instrumentation Workshop 2002 written by Gary A. Smith and published by American Institute of Physics. This book was released on 2002-12-06 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: The proceedings of the 10th Beam Instrumentation Workshop contains papers discussing the design principles and engineering issues of beam diagnostic and control instrumentation for charged particle accelerators and beam transport lines. The papers, presented at the 2002 Workshop, consist of tutorials, invited talks, and contributed oral and poster presentations.
Download or read book Beam Instrumentation Workshop written by and published by . This book was released on 1998 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INITIAL COMMISSIONING RESULTS FROM THE PEP II TRANSVERSE COUPLED BUNCH FEEDBACK SYSTEMS written by and published by . This book was released on 2003 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Initial commissioning results from the PEP-II transverse coupled-bunch feedback systems are discussed. In particular, the performance of key hardware and coupled-bunch damping results are described in some detail. Beam dynamics related measurements presented include beam transfer functions and selected modal growth and damping rates.
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 Results and Plans of the PEP II B Factory written by and published by . This book was released on 2004 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: PEP-II is an ee− B-Factory Collider located at SLAC operating at the Upsilon 4S resonance (3.1 GeV x 9 GeV). PEP-II has delivered, over the past five years, an integrated luminosity to the BaBar detector of about 240 fb−1 and has reached a luminosity of 9.21 x 1033/cm2/s. Steady progress is being made in reaching higher luminosity. The goal over the next several years is to reach a luminosity of at least 2.4 x 1034/cm2/s. The accelerator physics issues being addressed in PEP-II to reach this goal include the electron cloud instability, beam-beam effects, parasitic beam-beam effects, high RF beam loading, shorter bunches, lower beta y interaction region operation, and coupling control. A view of the PEP-II tunnel is shown in Figure 1. The present parameters of the PEP-II B-Factory are shown in Table 1 compared to the design. The present peak luminosity is over three times the design and the best integrated luminosity per month is 16 fb−1 that is five times the design. The highest luminosity per month is shown in Figure 2. The integrated luminosity over a month is shown in Figure 3 and the total integrated luminosity in Run 4 in shown in Figure 4. The progress in integrated luminosity has come from correcting the orbits, lowering beta y, moving the fractional horizontal tunes in both rings to just above the half integer (
Download or read book Jana auf der Farm written by and published by . This book was released on 2003 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advies aan de Interdepartementale Werkgroep ad hoc inzake de relaties met de minder ontwikkelde landen written by and published by . This book was released on 1961 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book BCP4 written by A. Ichiro Sanda and published by World Scientific. This book was released on 2001 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers the first strong evidence of the existence of CP violation in neutral B decays extracted from sophisticated B factories in the US and Japan. It also holds out the expectation of rare B decays and D, K physics in the near future. In addition, new physics beyond the Standard Model is described. Both experimental and theoretical points of view are given.
Download or read book Collimation Issues for the PEP II B factory written by and published by . This book was released on 1997 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: This note describes how beam collimation affects detector backgrounds at the collision point for the PEP-II B-factory, a joint effort of three laboratories: LBNL, LLNL, and SLAC. Beam collimation controls the transverse size as well as the maximum allowed energy spread of the beam. The location of synchrotron radiation masks is determined by the transverse size of the beam in that the masks must prevent radiation generated by beam particles located at large transverse beam positions from directly striking the detector beam pipe. Collimation of the energy spread of the beam is important in the control of backgrounds produced by beam particles that strike a gas molecule (lost beam particles). The author describes some preliminary information from background studies during the first months of commissioning the high energy ring of the PEP-II B-factory and present some model predictions for synchrotron radiation backgrounds when collimators are not present.
Download or read book Une Brute humaine written by and published by . This book was released on 1913 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Calibration of the Beam position Monitor System for the SLAC PEP II B Factory 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 Beam-Position Monitors (BPM) for the PEP-II B Factory consist of four 1.5-cm diameter button style pickups mounted on the diagonals of the quadrupole vacuum chambers. Before installation of the vacuum chambers in the quadrupole assemblies, the electrical center of the BPMs is measured with respect to the mechanical center in a calibration test stand. In this paper the calibration test stand is described and the precision and accuracy of the calibrations are presented. After installation of the quadrupole assemblies in the PEP-II tunnel, the passive attenuation for each channel of the system is measured to preserve the accuracy of the calibration. Finally, the active electronics includes an onboard calibrator. Results for these portions of the calibration are presented.
Download or read book Beam beam Effects for the PEP II B Factory written by and published by . This book was released on 1993 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a summary of a fairly extensive study of beam-beam issues that arise in the design of PEP-II. Most of these studies are carried out with ''strong-strong'' multiparticle tracking simulations. We focus on: choice of nominal beam-beam parameter, strength of the parasitic collisions, injection issues, performance and tradeoffs with unequal beam-beam parameters. We comment only briefly on beam lifetime. We conclude that: the beams are sufficiently well separated so that the parasitic collisions are effectively weak; that small inequalities in the beam-beam parameters may imply more comfortable performance margins; and that vertical injection with vertical beam separation is more comfortable than horizontal.
Download or read book Status and Future Plans of the PEP II B Factory 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 PEP-II e+e- collider [1,2,3,4] has been operating for two years with the BaBar detector at the energy of the Upsilon 4S resonance. The peak luminosity has reached 3.3 x 1033/cm2/s with 693 bunches with a positron current of 1.5 A and an electron current of 0.8 A. PEP-II has delivered in excess of 38 fb−1 of data to BaBar. The beam-beam tune shift limits are approaching 0.05-0.07 horizontally and 0.03-0.05 vertically [5]. The electron cloud instability ECI enlarges the positron beam size at high currents but is reduced by a solenoidal field on the vacuum chambers [6]. The beam currents in PEP-II are being raised to increase the number of bunches and the luminosity. Over the next few years the luminosity goal for PEP-II is 1034/cm2/s.
Download or read book B Physics And Cp Violation Bcp4 Proceedings Of The International Workshop written by T Ohshima and published by World Scientific. This book was released on 2001-09-25 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers the first strong evidence of the existence of CP violation in neutral B decays extracted from sophisticated B factories in the US and Japan. It also holds out the expectation of rare B decays and D, K physics in the near future. In addition, new physics beyond the Standard Model is described. Both experimental and theoretical points of view are given.
