Download or read book Bunch Coalescing and Bunch Rotation in the Fermilab Main Ring written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fermilab Tevatron I proton-antiproton collider project requires that the Fermilab Main Ring produce intense bunches of protons and antiprotons for injection into the Tevatron. The process of coalescing a small number of harmonic number h=1113 bunches into a single bunch by bunch-rotating in a lower harmonic rf system is described. The Main Ring is also required to extract onto the antiproton production target bunches with as narrow a time spread as possible. This operation is also discussed. The operation of the bunch coalescing and bunch rotation are compared with simulations using the computer program ESME. 2 refs., 8 figs.

Download or read book Bunch Coalescing in the Fermilab Main Ring written by and published by . This book was released on 1987 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A new rf system has been installed in the Fermilab Main Ring to coalesce up to 13 individual bunches of protons or antiprotons into a single high-intensity bunch. The coalescing process consists of adiabatically reducing the h = 1113 Main Ring rf voltage from 1 MV to less than 1 kV, capturing the debunched beam in a linearized h = 53 and h = 106 bucket, rotating for a quarter of a synchrotron oscillation period, and then recapturing the beam in a single h = 1113 bucket. The new system will be described and the results of recent coalescing experiments will be compared with computer-generated particle tracking simulations.

Download or read book Improvements in Bunch Coalescing in the Fermilab Main Ring written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper discusses the improvements in the performance of the bunch coalescing operation in the Fermilab Main Ring which have resulted in increased efficiency and the capability to produce bunches containing more than 1011 protons. 3 refs., 3 figs.

Download or read book Coalescing at 8 GeV in the Fermilab Main Injector written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For Project X, it is planned to inject a beam of 3 1011 particles per bunch into the Main Injector. To prepare for this by studying the effects of higher intensity bunches in the Main Injector it is necessary to perform coalescing at 8 GeV. The results of a series of experiments and simulations of 8 GeV coalescing are presented. To increase the coalescing efficiency adiabatic reduction of the 53 MHz RF is required. This results in ≈70% coalescing efficiency of 5 initial bunches. Data using wall current monitors has been taken to compare previous work and new simulations for 53 MHz RF reduction, bunch rotations and coalescing, good agreement between experiment and simulation was found. By increasing the number of bunches to 7 and compressing the bunch energy spread a scheme generating approximately 3 1011 particles in a bunch has been achieved. These bunches will then be used in further investigations.

Download or read book Simulation of Bunches Coalesing in the Main Ring in the Presence of a High frequency Wide band Resonator written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: During the first part of the coalescing process, bunches are being stretched until they fill the approx. =1 kV at 53 MHz bucket. Applying the ''Keil-Schnell-Boussard'' criteria for microwave instability inside that bunch gives: vertical bar Z/n vertical bar less than or equal to 5.6 .cap omega. for N/sub b/ = 101° ppB. It is very likely that local instabilities develop inside the bunch during the manipulation. The computer program ESME was run under these conditions to give an approximate picture of the bunch distortions. Outputs are presented here. Since microwave signals had been observed during the second part of coalescing (bunch rotation), some simulations have been done at that part. No catastrophic degradation showed up with the model used, as the computer outputs indicate. 35 figs.

Download or read book Bunch Lengthening in the Fermilab Main Ring During Storage written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: There are two known current dependent effects which can increase the length of stored bunched beams: (1) a reduction of the potential well of the applied rf focusing system; and (2) induced unstable oscillations of the bunches, which can stabilize at a longer length by the process of Landau damping. In the first case, the current distribution in the bunches, interacting with induced electromagnetic fields in the walls, leaves a wake field which acts back on the bunches. A new equilibrium bunch shape results, different from that due to the applied rf, and this new equilibrium bunch shape will slowly establish itself as the particles within the bunch move on their new trajectories. The second form of bunch instability is the single bunch type. These are characterized by high frequency (i.e. within bunch) oscillations in the microwave region and fast growth rates. The coherent effects are very difficult to observe and such instabilities tend to simulate an incoherent growth in the bunch. An attempt is made to describe the observation of bunch lengthening in the main ring in terms of both potential well distortion and induced microwave fields. It is found that the increase in bunch size is in qualitative agreement with an induced microwave instability if the wall (i.e. chamber discontinuities) couples to beam with a broad resistive impedance in the microwave region of the order of Z/n approximately 75 OMEGA (n is the mode number of the oscillation of frequency f = nf/sub rev/).

Download or read book Single Few Bunch Space Charge Effects at 8 GeV in the Fermilab Main Injector written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: For Project X, it is planned to inject a beam of 3 1011 particles per bunch into the Main Injector. Therefore, at 8 GeV, there will be increased space charge tune shifts and an increased incoherent tune spread. In preparation for these higher intensity bunches exploratory studies have commenced looking at the transmission of different intensity bunches at different tunes. An experiment is described with results for bunch intensities between 20 and 300 109 particles. To achieve the highest intensity bunches coalescing at 8 GeV is required, resulting in a longer bunch length. Comparisons show that similar transmission curves are obtained when the intensity and bunch length have increased by similar factors. This indicates the incoherent tune shifts are similar, as expected from theory. The results of these experiments will be used in conjugation with simulations to further study high intensity bunches in the Main Injector.

Download or read book Study of a Longitudinal Coupled bunch Instability in the Fermilab Main Ring written by Xianping Lu and published by . This book was released on 1994 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Simulation of Bunches Coalesing in the Main Ring in the Presence of a High frequency Wide band Resonator written by R. Garoby and published by . This book was released on 1986 with total page 35 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Search for Coupled bunch Instability in the Fermilab Main Injector 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 Fermilab Main Injector (MI) we are planning to double the bunch intensity from its design value by slip stacking. The accelerator consists of 18 rf cavities which operate at a harmonic number of 588. These cavities are known to have many higher ordered resonances. Longitudinal coupled-bunch instability induced by excitation of the rf cavities may be an important issue to be addressed in the intensity upgrade. Here we have carried out some simulation studies of the longitudinal coupled bunch instability to investigate bunch intensity limits. The results are presented in this paper.

Download or read book Space charge Effects in the Fermilab Main Ring at 8 GeV written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: I use computer tracking to investigate the effects of space-charge on particle motion in the Fermilab Main Ring at p = 8 GeV/c. The results are found to agree with the Laslett tuneshift formula. Simple model cases are also studied to speed up the tracking. The effects of synchrotron oscillations, via tune modulation and dispersion, are included. 2 refs., 5 figs.

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 Improving the Fermilab Booster Emittance written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Demand of high luminosity in the Tevatron collider in Fermilab makes the small beam emittance coming out of the 8 GeV Booster a highly desirable feature. This is because Booster bunches with small emittance, when eventually coalesced into Main Ring bunches, will ensure a high luminosity in the collider. Efforts have been made to identify factors limiting the phase space density in both transverse and longitudinal dimensions. The experimental result points to space charge induced tune spread at low energy as the main factor limiting the transverse phase space density, and the space charge induced phase space dilution at transition and longitudinal coupled bunch instability as the factors limiting the longitudinal phase space density. To counteract these factors, a set of harmonic correction sextupoles and skew sextupoles were implemented to reduce the third order resonances in the transverse case. In the longitudinal case a .gamma./sub t/-jump system was implemented to ease the bunch tumbling after transition, and various schemes to damp the longitudinal coupled bunch instability are either implemented or being reviewed. Future plans and efforts will be mentioned briefly at the end of this article. 3 refs., 8 figs., 1 tab.

Download or read book Physics of Particle Accelerators written by Margaret Dienes and published by . This book was released on 1989 with total page 2398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Explanation of Persistent High Frequency Density Structure in Coalesced Bunches written by and published by . This book was released on 1988 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been observed that after the Main Ring rf manipulation of coalescing (where 5 to 13 primary bunches are transferred into a single rf bucket) the new secondary bunch displays evidence of high frequency density structure superimposed on the approximately Gaussian longitudinal bunch length distribution. This structure is persistent over a period of many seconds (hundreds of synchrotron oscillation periods). With the help of multiparticle simulation programs, an explanation of this phenomenon is given in terms of single particle longitudinal phase space dynamics. No coherent effects need be taken into account. 6 refs., 10 figs.

Download or read book Main Ring Bunch Spreaders written by Gerald P. Jackson and published by . This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance of the Fermilab Main Ring During the 1988 89 Tevatron Collider Operation written by and published by . This book was released on 1989 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Fermilab Main Ring serves as injector for the Tevatron at 150 GeV/c and as a source of 120 GeV/c protons for antiproton production. This paper discusses the Main Ring performance--intensity, reliability, and efficiency--during the present Collider run. Also discussed are questions related to emittance and emittance growth, both transverse and longitudinal, and the impact of Main Ring losses on the Collider experiments. 4 refs., 3 figs.