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 Beam beam Studies for the Tevatron written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the first stage of Run II, the Tevatron will be operated with 36 bunches in each beam with bunch separations of 396 nanoseconds. The expected peak luminosity is L= 8.6 x 10[sup 31]cm[sup[minus]2]sec[sup[minus]1] with an average number of 2.3 interactions per bunch crossing. In the second stage of Run II, the goal is to increase the luminosity to about 1.5x10[sup 32] cm[sup[minus]2]sec[sup[minus]1]. If the bunch spacing were kept constant, the average number of interactions per bunch crossing would increase to about 4. This is thought to be unacceptably large and might saturate the efficiency of the detectors. This is the main reason for decreasing the bunch spacing at higher luminosities. One possibility is to reduce the bunch spacing to 132 nanoseconds which lowers the average number of interactions to an acceptable value of 1.4. This shorter bunch spacing though has several consequences on beam dynamics. Collisions between bunches will now occur every 19.78m. This is shorter than the distance of the nearest separators from the main IPs at B0 and D0. Consequently the beams will not be separated at the parasitic collisions nearest to the IPs if the geometry of the orbit is left unchanged. A sketch of this orbit is seen in the top part of Figure 1. This will lead to unacceptably large beam losses and background. Moving the separators closer to the detectors does not separate the beams sufficiently at the locations PC1L and PC1R. The phase advance from the first available position for the separators to these points is too small for the separator strengths that are available. One way to increase the transverse separation between the beams is to make the beams cross at an angle at the IPs. The optimum crossing angle depends upon a number of issues and requires a detailed investigation. The issues include a reduction in the luminosity, change in the beam-beam tune spreads, excitation of synchro-betatron resonances, orbit offset in IR quadrupoles which increases the nonlinear fields seen by the beams, required separation between the beams at the nearest parasitic collisions, the dispersion wave generated by the orbit offset, increase in the strength of the coupling etc. A crossing angle of[approximately][+-]200[micro]rad in the 45 degree plane separates the beams by[approximately] 4[sigma] at the first parasitic collision. A sketch of the orbits with a crossing angle is shown in the bottom part of Figure 1.

Download or read book Synchro betatron Resonances Driven by the Beam beam Interaction Summary Talk written by and published by . This book was released on 1994 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a selective summary of the discussions on beam-beam-driven synchrobetatron resonances at the 6th Advanced ICFA Beam Dynamics Workshop on the subject ''Synchro-Betatron Resonances, '' held in Funchal (Madeira, Portugal), October 24--30, 1993.

Download or read book Coherent Synchro betatron Oscillations Excited by the Beam Beam Interaction written by Y. Kamiya and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coherent Synchro betatron Oscillations Excited by the Beam beam Interaction written by and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this note, a third possible coherent instability excited by the beam-beam interaction will be discussed. This time it involves the longitudinal motion of the bunches. What is studied is the possibility of beam-beam excited longitudinal dipole oscillations or coherent synchro-betatron oscillations in which the longitudinal and transverse motions are coupled through the beam-beam collisions. We suggest that such modes of oscillations exist when there is a finite dispersion at the interaction point.

Download or read book The Effects of Betatron Phase Advances on Beam beam and Its Compensation in RHIC written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this article we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used in this study. We also scan the betatron phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

Download or read book The Effects of Phase Advances Between Interaction Points written by and published by . This book was released on 2011 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this note we perform simulation studies to investigate the effects of betatron phase advances between the beam-beam interaction points on half-integer resonance driving term, second order chromaticty and dynamic aperture in RHIC. The betatron phase advances are adjusted with artificial matrices inserted in the middle of arcs. The lattices for the 2011 RHIC polarized proton (p-p) run and 2010 RHIC Au-Au runs are used. We also scan the phase advances between IP8 and the electron lens for the proposed Blue ring lattice with head-on beam-beam compensation.

Download or read book Physics Briefs written by and published by . This book was released on 1987 with total page 1232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Synchro betatron Effects in Hadron Machines written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report discusses the following topics: synchro-betatron resonances; synchro-betatron effects; ground motion; current ripple; beam extraction; and phase diagram and chaos.

Download or read book Synchro betatron Resonances in the 8 GeV Proton Driver written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The major difference of these two versions is the size (circumference) and the maximum energy. In the first study, the circumference is chosen to be 711.3m, which is 1.5 times the present Booster, with the maximum energy of 16 GeV. In the second version, it is mandated to be the same as Booster together with the same maximum energy of 8 GeV. One of the major impacts of the reduced size of the ring is the inevitable reduction in the total length of available space for injection/collimation/extraction systems and for rf cavities, 14 slots of 7.43m each in the smaller ring compared with 24 slots of 6.15m each in the larger ring. Since each cavity occupies a slot of 2.35m and 22 cavities are desirable, seven or eight slots out of 14 in the smaller ring must be reserved for rf, only six or seven remaining for all other systems. The constraint in space is particularly troublesome for the extraction system since the beam loss at extraction (at the highest beam energy) is the major concern of any high intensity proton machines.

Download or read book Ambient Betatron Motion and Its Excitation by Ghost Lines in Tevatron written by and published by . This book was released on 2011 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transverse betatron motion of the Tevatron proton beam is measured and analyzed. It is shown that the motion is coherent and excited by external sources of unknown origins. Observations of the time varying 'ghost lines' in the betatron spectra are reported.

Download or read book Coherent Synchro betatron Resonance written by and published by . This book was released on 2006 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coherent synchro-betatron resonances can present a serious limit for low-energy synchrotrons with strong space charge. Here, an excitation of a dipole transverse mode is considered at resonance condition.

Download or read book Tevatron Run II Performance and Plans written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fermilab accelerator complex has been operating Run II for approximately one year. In this mode 36 proton bunches collide with 36 antiproton bunches at 2 interaction regions in the Tevatron at 980 GeV beam energy. The long range goal in Run II is to obtain a total integrated luminosity of 15 pb−1. The current status and performance of the accelerator complex is described, including the Tevatron, Main Injector, Antiproton Source, and Recycler Ring. Future upgrade plans and prospects for reaching the admittedly ambitious long range goal are presented.

Download or read book Excitation of Betatron synchrotron Resonances by a Dispersion in the Cavities written by A. Piwinski and published by . This book was released on 1976 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vertical Synchrobetatron Resonances Due to Beam beam Interaction with Horizontal Crossing written by D. V. Pestrikov and published by . This book was released on 1993 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Coherent Synchro betatron Resonances Driven by Localized Wake Fields written by Y. H. Chin and published by . This book was released on 1985 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Ejection of the Electron Beam from the Betatron written by Sherwood L. Fawcett and published by . This book was released on 1950 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: