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in subjects: "Antiproton Beams"

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Schemes for anti pp interactions at ISABELLE

Various schemes for obtaining anti pp interactions are outlined, and the luminosities obtainable for each case calculated. In the simplest realistic case, a luminosity of 1.3 x 10/sup 29/ is obtained with a 13 hour filling time. The addition of special rf systems in both the AGS and ISABELLE give a scheme with luminosity 8 x 10/sup 29/ in 6 hours. The use of stochastic cooling to stack raises the luminosity to as high as 10/sup 31/ but the filling time is then 68 hours. Finally a scheme is cons… more

Date: September 8, 1977

Creator: Palmer, Robert B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Considerations of bunch-spacing options for multi-bunch operation of the Tevatron Collider

This discussion will consider a number of points relevant to limitations, advantages and disadvantages of various arrangements of bunches in the Tevatron proton-antiproton collider. The considerations discussed here will be limited to: (a) bunch spacing symmetry and relation to the relative luminosity at B0 and D0 and the beam-beam interaction with separated beams; (b) bunch spacing constraints imposed by Main Ring RF coalescing and the optics of beam separation at B0 and D0; and (c) bunch spac… more

Date: December 14, 1989

Creator: Dugan, G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The creation of high energy densities with antimatter beams

The use of antiprotons (and antideuterons) for the study of the behavior of nuclear matter at high energy density is considered. It is shown that high temperatures and high energy densities can be achieved for small volumes. Also investigated is the strangeness production in antimatter annihilation. It is found that the high rate of Lambda production seen in a recent experiment is easily understood. The Lambda and K-short rapidity distributions are also reproduced by the model considered. 11 re… more

Date: January 1, 1989

Creator: Gibbs, W.R.; Kruk, J.W. (Los Alamos National Lab., NM (USA) & Rice Univ., Houston, TX (USA). Bonner Nuclear Labs.)

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Elementary stochastic cooling

Major headings in this review include: proton sources; antiproton production; antiproton sources and Liouville, the role of the Debuncher; transverse stochastic cooling, time domain; the accumulator; frequency domain; pickups and kickers; Fokker-Planck equation; calculation of constants in the Fokker-Planck equation; and beam feedback. (GHT)

Date: December 1, 1983

Creator: Tollestrup, A.V. & Dugan, G

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Power combiners/dividers for loop pickup and kicker arrays for FNAL stochastic cooling rings

The anti-proton accumulator and debuncher at FNAL will use stochastic methods to ''cool'' the beam. Pairs of quarter-wavelength directional-coupler loops are used to detect and kick the beam. The loops are copper plates which are flush with the upper and lower wall of a rectangular beam pipe. The plates, when surrounded by a properly sized pocket, form a 100-ohm transmission-line directional coupler. As the beam passes, a signal which gives position and time information, is induced in the plate… more

Date: May 1, 1985

Creator: Johnson, J. K. & Nemetz, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Suppression of propagating TE modes in the FNAL antiproton source stochastic beam cooling system

A method of attenuating the propagation of waveguide modes in the stochastic cooling array beam pipes to be utilized in the accumulator and debuncher rings of the Fermilab antiproton source is described. The attenuation method treated involves lining the vertical walls of the beam pipes with a ferrimagnetic material. The general solution for propagation in a nonhomogeneously loaded waveguide is presented along with numerical results specific to the antiproton source beam cooling system. Also de… more

Date: May 1, 1985

Creator: Barry, W.C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Some design considerations for pbar target sweeping station

This report summarizes the results of some recent calculations useful to design the beam sweeping station to produce high intensity pbar beam at AP0. With various on-going and planned intensity upgrade at the accelerator including the main injector the primary beam intensity on the pbar target is expected to increase. But some complications would arise from the existing method of pbar production. A study of the heavy metal targets used when the beam intensity was about 1.0 {times} 10{sup 12}, h… more

Date: June 1, 1991

Creator: Bhat, C.M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Polarization experiments at Fermilab (E-581/704)

The Fermilab polarized beam and antiproton beams in the MP beam line are described. The Fermilab polarized-beam program using this facility are presented.

Date: January 1, 1987

Creator: Yokosawa, Akihiko

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Physics overview of the Fermilab Low Energy Antiproton Facility Workshop

A physics overview is presented of the Fermilab workshop to consider a possible high flux, low energy antiproton facility that would use cooled antiprotons from the accumulator ring of the Tevatron collider. Two examples illustrate the power of each a facility to produce narrow states at high rates. Physics topics to which such a facility may be applied are reviewed.

Date: May 1, 1986

Creator: Chanowitz, Michael S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Comparison between theoretical predictions and tracking

The beam-beam interaction in a proton-antiproton collider has been an outstanding issue for a long time. Several theoretical predictions have been made in the past which range from the appearance of single beam-beam driven resonances to the onset of stochasticity and Arnold diffusion and the presence of chaotic trajectories. All these effects would cause a limit on the maximum strength of the beam-beam interaction, the so called beam-beam tune-shift, and speculative values have been offered ran… more

Date: January 1, 1985

Creator: Ruggiero, Alessandro G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of frequency response of LBL stochastic cooling arrays for TeV-I storage rings

Lawrence Berkeley Laboratory (LBL) has developed electrodes for the stochastic cooling system which is used in the anti-proton source in TeV-I at Fermilab. The electrodes are in the form of a pair of stripline couplers or loops, the elements of which are mounted on opposite sides of the beam. We have made two different couplers of similar design, the one to operate in the frequency range 1-2 GHz, the other, 2-4 GHz. We have made two different types of measurements; the one involving the respons… more

Date: May 1, 1985

Creator: Goldberg, D.A.; Lambertson, G.R.; Voelker, F. & Shalz, L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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The design and performance of the FNAL high-energy polarized beam facility

We describe a new polarized-proton and -antiproton beam with 185-GeV/c momentum in the Fermilab MP beam line which is currently operational. The design uses the parity-conserving decay of lambda and antilambda hyperons to produce polarized protons and antiprotons, respectively. A beam-transport system minimizes depolarization effects and uses a set of 12 dipole magnets that rotate the beam-particle spin direction. A beam-tagging system determines the momentum and polarization of individual beam… more

Date: January 1, 1989

Creator: Tanaka, Nobuyuki.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Physics with bottled antiprotons

The same beam cooling techniques that has allowed for high luminosity antiproton experiments at high energy also provides the opportunity for experiments at ultra-low energy. Through a series of deceleration stages, antiprotons collected and cooled at the peak momentum for production can be made available at thermal or sub-thermal energies. In particular, the Los Alamos collaboration is developing an RFQ-pulsed ion trap beam line for the antiproton gravitational mass experiment (PS200) at LEAR … more

Date: January 1, 1986

Creator: Hynes, M.V. & Campbell, L.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Debunching into a bucket of lower harmonic number

The adiabatic debunching of beam from buckets of higher harmonic number into waiting buckets of lower harmonic number is a critical step in the current scheme of operation for Tev I. The optimum choice of rf system parameters for this ''bunch coalescing'' process is not immediately obvious. In this note two examples are presented along with generalizations based upon them and experience with the Tevatron I design which can simplify the selection of appropriate parameters for different condition… more

Date: December 9, 1987

Creator: MacLachlan, J.A. & Griffin, J.E.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Electron cooling rates characterization at Fermilab's Recycler

A 0.1 A, 4.3 MeV DC electron beam is routinely used to cool 8 GeV antiprotons in Fermilab's Recycler storage ring [1]. The primary function of the electron cooler is to increase the longitudinal phase-space density of the antiprotons for storing and preparing high-density bunches for injection into the Tevatron. The longitudinal cooling rate is found to significantly depend on the transverse emittance of the antiproton beam. The paper presents the measured rates and compares them with calculati… more

Date: June 1, 2007

Creator: Prost, Lionel R. & Shemyakin, A.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Optimization of the Helical Orbits in the Tevatron

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 … more

Date: June 1, 2007

Creator: Alexahin, Y.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Measurement of the ttbar production cross section in the MET+jets channel at CDF

This thesis is focused on an inclusive search of the t{bar t} {yields} E{sub T} + jets decay channel by means of neural network tools in proton antiproton collisions at {radical}s = 1.96 TeV recorded by the Collider Detector at Fermilab (CDF). At the Tevatron p{bar p} collider top quarks are mainly produced in pairs through quark-antiquark annihilation and gluon-gluon fusion processes; in the Standard Model description, the top quark then decays to a W boson and a b quark almost 100% of the tim… more

Date: March 1, 2008

Creator: Compostella, Gabriele & /INFN, Trento

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Experimental and simulation studies of beam-beam compensation with Tevatron electron lenses

Initially the Tevatron Electron Lenses (TELs) were intended for compensation of the beam-beam effect on the antiproton beam [1]. Owing to recent increase in the number of antiprotons and reduction in their emittance, it is the proton beam now that suffers most from the beam-beam effect [2]. We present results of beam studies, compare them with the results of computer simulations using LIFETRAC code and discuss possibilities of further improvements of the Beam-Beam Compensation efficiency in the… more

Date: June 1, 2007

Creator: Kamerdzhiev, V.; Alexahin, Y.; Shiltsev, V.; Valishev, A.; Zhang, X.L.; /Fermilab et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Tevatron Electron Lenses: Design and Operation

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), d… more

Date: August 1, 2008

Creator: Shiltsev, Vladimir; Bishofberger, Kip; Kamerdzhiev, Vsevolod; Kozub, Sergei; Kufer, Matthew; Kuznetsov, Gennady et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Status of the Fermilab Recycler

The author presents the current operational status of the Fermilab Recycler Ring. Using a mix of stochastic and electron cooling, we prepare antiproton beams for the Fermilab Tevatron Collider program. Included are discussion of stashing and cooling performance, operational scenarios, and collider performance.

Date: September 1, 2007

Creator: Derwent, P.F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental Studies of Compensation of Beam-Beam Effects with Tevatron Electron Lenses

Applying the space-charge forces of a low-energy electron beam can lead to a significant improvement of the beam-particle lifetime limit arising from the beam-beam interaction in a high-energy collider [1]. In this article we present the results of various beam experiments with 'electron lenses', novel instruments developed for the beam-beam compensation at the Tevatron, which collides 980-GeV proton and antiproton beams. We study the dependencies of the particle betatron tunes on the electron … more

Date: February 1, 2008

Creator: Shiltsev, V.; /Fermilab; Alexahin, Yu.; Bishofberger, Kip; Kamerdzhiev, V.; Parkhomchuk, V. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Diagnostics of the Fermilab Tevatron using an AC dipole

The Fermilab Tevatron is currently the world's highest energy colliding beam facility. Its counter-rotating proton and antiproton beams collide at 2 TeV center-of-mass. Delivery of such intense beam fluxes to experiments has required improved knowledge of the Tevatron's beam optical lattice. An oscillating dipole magnet, referred to as an AC dipole, is one of such a tool to non-destructively assess the optical properties of the synchrotron. We discusses development of an AC dipole system for th… more

Date: August 1, 2008

Creator: Miyamoto, Ryoichi

Item Type: Thesis or Dissertation

Partner: UNT Libraries Government Documents Department

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Run II luminosity progress

The Fermilab Tevatron Collider Run II program continues at the energy and luminosity frontier of high energy particle physics. To the collider experiments CDF and D0, over 3 fb{sup -1} of integrated luminosity has been delivered to each. Upgrades and improvements in the Antiproton Source of the production and collection of antiprotons have led to increased number of particles stored in the Recycler. Electron cooling and associated improvements have help make a brighter antiproton beam at collis… more

Date: June 1, 2007

Creator: Gollwitzer, K.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Experimental demonstration of colliding beam lifetime improvement by electron lenses

We report successful application of space-charge forces of a low-energy electron beam for improvement of particle lifetime determined by beam-beam interaction in high-energy collider. In our experiments, an electron lens, a novel instrument developed for the beam-beam compensation, was set on a 980-GeV proton bunch in the Tevatron proton-antiproton collider. The proton bunch losses due to its interaction with antiproton beam were reduced by a factor of 2 when the electron lens was operating. We… more

Date: October 1, 2007

Creator: Shiltsev, Vladimir; Alexahin, Yuri; Kamerdzhiev, Vsevolod; Kuznetsov, Gennady; Zhang, Xiao-Long; /Fermilab et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department