Download or read book Long range Beam beam Interactions in the Tevatron written by and published by . This book was released on 1990 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fermilab upgrade plans for the collider operation include a separation scheme in the Tevatron, in which protons and antiprotons are placed on separate helical orbits. The average separation distance between the closed orbits will be 5[sigma] ([sigma] of the proton bunch) except at the interaction regions, B0 and D0, where they collide head-on. The maximum beam-beam total tune shift in the Tevatron is approximately 0.024 (the workable tune space between 5th and 7th order resonances), which was reached in the 1988--1989 collider tun. Helical separation scheme allows us to increase the luminosity by reducing the total beam-beam tune shift. The number of bunches per beam will be 6 in the 1991 collider tun, to be increased to 36 in the following collider runs. To test the viability of this scenario, helical orbit studies are being conducted. The most recent studies concentrated on the injection of 36 proton bunches, procedures related to opening and closing of the helix, the feed-down circuits and the beam-beam interaction. In this paper, we present the results of the beam-beam interaction studies only. Our emphasis is on the tune shift measurements and the comparison to simulation. 4 refs., 9 figs., 2 tabs.
Download or read book Beam beam Interactions at the Tevatron in Run IIa written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Tevatron in Run IIa will operate with three trains of twelve bunches each. The impact of the long-range interactions on beam stability will be more significant compared to Run I. We study these beam-beam interactions (head-on and long-range) with particle tracking using two different codes. The model includes machine nonlinearities such as the field errors of the Interaction Region quadrupoles and the chromaticity sextupoles. Tune footprints and dynamic apertures are calculated for different bunches in a train.
Download or read book Een ghebedt der Isra liten vvoonachtich in Hollandt voor Frederic Hendrick prince van Orangien c derwijle hy s Hertoghen bosch de voornaemste stadt van Brabant belegerde written by and published by . This book was released on 1630 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Beam beam Interactions in Run IIa at the Tevatron written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We discuss the impact of the beam-beam interactions on Run IIa operation at the design parameters. We focus on the seventy long-range interactions which primarily determine the stable region in phase space and limit the lifetime. We discuss recent improvements in lifetime at injection and dynamic aperture calculations at collision.
Download or read book New Aspects of Beam beam Interactions in Hadron Colliders written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Beam-beam phenomena have until now limited the beam currents and luminosity achievable in the Tevatron. injected proton currents are about ten times larger than the anti-proton currents so beam-beam effects have largely acted on the anti-protons and at all stages of the operational cycle. The effects of the anti-protons on the protons have until now been relatively benign but that may change at higher anti-proton currents. After 36 bunches of protons are injected and placed on the proton helix, anti-protons are injected four bunches at a time. After all bunches are injected, acceleration to top energy takes bout 85 seconds. After reaching flat top, the optics around the interaction regions (IRs) is changed to lower [beta]* from 1.6 m to 0.35 m at B0 and D0. The beams are brought into collision by collapsing the separation bumps around the IPs. During a high energy physics store each bunch experiences two head-on collisions with bunches in the opposing beam and seventy long-range interactions. At all other stages of the operational cycle, each bunch experiences only long-range interactions--seventy two in all. Performance limitations from beam-beam effects until now have been primarily due to these long-range interactions. The anti-proton losses at 150 GeV have decreased during the last year mostly due to better control of the orbits, tunes and chromaticities. During this period proton intensities have increased about 50%, thus anti-proton losses at 150 GeV have not been very dependent on proton intensities. Anti-proton and proton losses on the ramp together with proton losses at 150 GeV are the dominant contributors to the Tevatron inefficiency.
Download or read book Theoretical Studies of Beam beam Effects in the Tevatron at Collision Energy written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The dynamics due to the long-range beam-beam interactions depends on several beam parameters such as tunes, coupling, chromaticities, beam separations, intensities and emittances. They have developed analytical tools to calculate, for example, amplitude dependent tune shifts and chromaticities, beam-beam induced coupling, and betatron and synchro-betatron resonance widths. They report on these calculations and dynamic aperture calculations with long-term tracking. These theoretical results are compared with observations at collision energy and used to predict performance at design values of beam intensities and emittances.
Download or read book Beam beam Effects in the Tevatron Run II written by R. Moore and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams are significant sources of beam loss and lifetime limitations in the Tevatron Collider Run II (2001-present). We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in high energy physics (HEP) operation, predict the performance for planned luminosity upgrades and discuss ways to improve it.
Download or read book Tevatron Beam beam Simulations at Injection Energy written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Major issues at Tevatron injection are the effects of 72 long-range beam-beam interactions together with the machine nonlinearity on protons and anti-protons. We look at particle tracking calculations of Dynamic Aperture (DA) under present machine conditions. Comparisons of calculations with observations and experiments are also presented in this report.
Download or read book Accelerator Physics at the Tevatron Collider written by Valery Lebedev and published by Springer. This book was released on 2014-05-29 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the developments in accelerator physics and technology implemented at the Tevatron proton-antiproton collider, the world’s most powerful accelerator for almost twenty years prior to the completion of the Large Hadron Collider. The book covers the history of collider operation and upgrades, novel arrangements of beam optics and methods of orbit control, antiproton production and cooling, beam instabilities and feedback systems, halo collimation, and advanced beam instrumentation. The topics discussed show the complexity and breadth of the issues associated with modern hadron accelerators, while providing a systematic approach needed in the design and construction of next generation colliders. This book is a valuable resource for researchers in high energy physics and can serve as an introduction for students studying the beam physics of colliders.
Download or read book Beam beam Effects in the Tevatron written by and published by . This book was released on 2005 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Tevatron in Collider Run II (2001-present) is operating with 6 times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams have been significant sources of beam loss and lifetime limitations. We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in operations, predict the performance for planned luminosity upgrades, and discuss ways to improve it.
Download or read book Long range Beam beam Effect in the Tevatron written by and published by . This book was released on 2013 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Feasibility Study of Beam beam Compensation in the Tevatron with Wires written by Tanaji Sen and published by . This book was released on 2005 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: We explore the possibility of compensating long-range beam-beam interactions in the Tevatron by current carrying wires. Compensation strategies depend on whether the compensation is done close to the interaction or nonlocally, on the aspect ratio of the strong beam and on other details. Strategies for each case have been developed and applied to the Tevatron. We discuss the results of these strategies at injection and collision energy.
Download or read book Experimental Demonstration of Beam beam Compensation by Tevatron Electron Lenses and Prospects for the LHC written by and published by . This book was released on 2007 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electromagnetic long-range and head-on interactions of high intensity proton and antiproton beams are significant sources of beam loss and lifetime limitations in the Tevatron Collider Run II (2001-present). We present observations of the beam-beam phenomena in the Tevatron and results of relevant beam studies. We analyze the data and various methods employed in high energy physics (HEP) operation, predict the performance for planned luminosity upgrades and discuss ways to improve it.
Download or read book Performance of a Beam Monitor in the Fermilab Tevatron Using Synchrotron Light written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Synclite, the beam monitor in the Fermilab Tevatron using synchrotron light is described. The calibration, monitoring and performance of the system is discussed. Observation of some effects of long range beam-beam interactions seen in the beam monitor will be presented as well as a measurement of DC beam in the Tevatron.
Download or read book Excitation of the Synchro betatron Resonances by the Beam beam Interaction in the Tevatron Run II Lattice written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Effect of different mechanisms of the synchro-betatron coupling (dispersion function at the interaction points, chromatic tune modulation, finite bunch length) on the p-bar stability in the Tevatron Run II configuration is considered. It is found that the long-range interactions in the presence of large dispersion produce large contribution ((approximately)10) to the chromaticity of the betatron tunes. This chromaticity, in its turn, can give rise to multiple synchrotron satellites of the betatron resonances increasing their effective width. Novel formulae are presented which permit to significantly speed up analytical calculations of the beam-beam tuneshifts and resonance strength.
Download or read book Tevatron Electron Lenses written by and published by . This book was released on 2011 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fermilab's Tevatron is currently the world's highest energy accelerator in which tightly focused beams of 980 GeV protons and antiprotons collide at two dedicated interaction points (IPs). Both beams share the same beam pipe and magnet aperture and, in order to avoid multiple detrimental head-on collisions, the beams are placed on separated orbits everywhere except the main IPs by using high-voltage (HV) electrostatic separators. The electromagnetic beam-beam interaction at the main IPs together with the long-range interactions between separated beams adversely affect the collider performance, reducing the luminosity integral per store (period of continuous collisions) by 10-30%. Tuning the collider operation for optimal performance becomes more and more cumbersome as the beam intensities and luminosity increase. The long-range effects which (besides being nonlinear) vary from bunch to bunch are particularly hard to mitigate. A comprehensive review of the beam-beam effects in the Tevatron Collider Run II can be found in Ref. [1]. The beam-beam effects have been the dominating sources of beam loss and lifetime limitations in the Tevatron proton-antiproton collider [1]. Electron lenses were originally proposed for compensation of electromagnetic long-range and head-on beam-beam interactions of proton and antiproton beams [2]. Results of successful employment of two electron lenses built and installed in the Tevatron are reported in [3,4,5]. In this paper we present design features of the Tevatron electron lenses (TELs), discuss the generation of electron beams, describe different modes of operation and outline the technical parameters of various subsystems.
Download or read book Optimization of the Helical Orbits in the Tevatron written by and published by . This book was released on 2007 with total page 3 pages. Available in PDF, EPUB and Kindle. Book excerpt: To avoid multiple head-on collisions the proton and antiproton beams in the Tevatron move along separate helical orbits created by 7 horizontal and 8 vertical electrostatic separators. Still the residual long-range beam-beam interactions can adversely affect particle motion at all stages from injection to collision. With increased intensity of the beams it became necessary to modify the orbits in order to mitigate the beam-beam effect on both antiprotons and protons. This report summarizes the work done on optimization of the Tevatron helical orbits, outlines the applied criteria and presents the achieved results.
