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The Early Antiproton Work [Nobel Lecture]

Description: Early work on the antiproton, particularly that part which led to the first paper on the subject, is described. Conclusions that can be drawn purely from the existence of the antiproton are discussed. (W.D.M.)
Date: December 15, 1959
Creator: Chamberlain, O.
Partner: UNT Libraries Government Documents Department

Observation of Antiprotons

Description: One of the striking features of Dirac's theory of the electron was the appearance of solutions to his equations which required the existence of an antiparticle, later identified as the positron.
Date: October 19, 1955
Creator: Chamberlain, Owen; Segre, Emilio; Wiegand, Clyde & Ypsilantis,Thomas
Partner: UNT Libraries Government Documents Department

Antiproton Star Observed in Emulsion

Description: In connection with the antiproton investigation at the Bevatron we planned and carried out a photographic-emulsion exposure in a magnetically selected beam of negative particles. The magnetic system was identical to the first half (one deflecting magnet and one magnetic lens) of the system used in the antiproton experiment of Chamberlain, Segre, Wiegand, and Ypsilantis. The selected particles left the copper target in the forward direction with momentum 1.09 Bev/c.
Date: December 1, 1955
Creator: Chamberlain, Owen; Chupp, Warren W.; Goldhaber, Gerson; Segre,Emilio; Wiegand, Clyde; Amaldi, E. et al.
Partner: UNT Libraries Government Documents Department

3Q120 Low Gradient Behaviour-Companion Report

Description: Three 3Q120 magnets--representative of those in the AP 1 line--have been measured with a harmonics probe at MDTF at both low (0-48 A) and high (to >= 400 A). The intent of the measurements was to learn their behavior at the low gradients necessary to transport 8 Gev antiprotons back through the AP 1 line for injection into the Main Ring. This paper describes some aspects of the measurements that were not included in the main paper, in order to keep the size of the main report reasonably small. It includes as Appendix I a chronology of the measurements made and significant changes made to the measurement apparatus and analysis programs.
Date: October 1, 1985
Creator: Wehmann, A.
Partner: UNT Libraries Government Documents Department

The Fermilab Pbar Collider: Machine and Detectors

Description: This paper is a condensed version of the talk presented at the Fifth Topical Conference on Proton-Antiproton Collisions, St. Vincent, Italy, February 26, 1985. The principle objective of the talk was to inform the community of the present status of the collider at Fermilab. Since progress is rapid on both the accelerator and the detectors, much of the material presented would be out of date by the time these proceedings are published.
Date: February 1, 1985
Creator: Malamud, E.
Partner: UNT Libraries Government Documents Department

The Velocity-Selecting Cerenkov Counter

Description: A number of varieties of velocity-selecting Cerenkov counters have been described by Dr. John Marshall. The authors will present a description of a counter different from any described by Marshall in his review article, but of the same type mentioned descriptively by Marshall in another article under the heading ''Cylindrical mirror counter without lens''. Some tests of this type of counter were carried out by S.J. Lindenbaum and L.C. Yuan. The counter we describe was developed for the detection of a small fraction of antiprotons in a beam of negative particles originating at the target of the Bevatron. As far as the authors are aware, this represents the first practical use of a velocity-selecting Cerenkov counter in an experimental investigation.
Date: April 17, 1956
Creator: Chamberlain, Owen & Weigand, Clyde
Partner: UNT Libraries Government Documents Department

Antiproton Yields for Stochastic Accumulation

Description: Two sets of parameters have been developed to study stochastic accumulation. The question arises of the size of the transverse emittance required to achieve an antiproton yield of 1.2 x 10{sup 8} {bar p}'s/MR cyc1e for 4.5 GeV and 8 GeV {bar p} kinetic energies, given a full momentum acceptance of 4%. The results quoted in the paper are obtained with a Monte Carlo program which uses a fit to the {bar p} production invariant cross section that has been presented previously. An article describing the program is in preparation.
Date: July 15, 1981
Creator: Hojnat, Carlos & Ginneken, A.Van
Partner: UNT Libraries Government Documents Department

Measurement of Emittance of Beam in the Debuncher During Stacking

Description: The emittance of antiprotons in the debuncher was measured using two methods during normal stacking conditions. With 2.3 seconds of cooling the vertical emittance was found to be 3.6 {pi} mm-mr using scraper D:TJ308, and 2.9 {pi} mm-mr using the profile on SEM806. With 6.9 seconds of cooling time time the measured horizontal emittance was 2.1 {pi} mm-mr using D:RJ306 v.s. 1.9 {pi} mm-mr using SEM806; but with 2.3 seconds of cooling the measured emittance in the debuncher was larger than in the DTOA line, 4.5 {pi} mm-mr v.s. 2.8 {pi} mm-mr. This suggests that some beam is being scraped on a horizontal aperture restriction someplace in the extraction process.
Date: December 11, 1991
Creator: Halling, Mike
Partner: UNT Libraries Government Documents Department

Transverse Emittance Growth in the Fermilab Antiproton Accumulator with High-Current Antiproton Stacks

Description: Transverse emittance growth due to coherent instabilities in the Fermilab antiproton accumulator imposes a limit on the number of antiprotons which can be stacked and subsequently transferred to the collider. Consequences, the diagnosis and control of these phenomena has been required to further increase the luminosity of the collider. In this paper they present an overview of the techniques by which these instabilities have been studied and the methods by which they are controlled.
Date: January 1, 1992
Creator: Werkema, Steven J.; Peterson, David W.; Zhou, Ping & /Fermilab
Partner: UNT Libraries Government Documents Department

Optimization of the 8 GeV AP3-P1 Lattice for Antiproton Transfers

Description: During 8 GeV antiproton transfers between the Accumulator to the Main Injector, the antiprotons must travel through four separate beam lines, AP3, AP1, P2, and P1. This note describes the optimization of a single lattice that describes these beam lines for 8 GeV antiproton transfers from the Accumulator to the Main Injector and 8 GeV proton transfers from the Main Injector to the Accumulator.
Date: January 22, 2001
Creator: McGinnis, Dave
Partner: UNT Libraries Government Documents Department

Quadrupole Focussing and Quadrupole Steering Tolerances for the 8 GeV AP3-P1 Lattice

Description: This note will outline the sensitivity to emittance blowup of antiproton transfers due to quadrupole focussing and quadrupole steering errors in the 8 GeV AP3-P1 transfer line. It will be shown that these tolerances are much larger than the dipole steering tolerances discussed in PBAR Note 649. This note will use the lattice discussed in PBAR Note 648.
Date: February 5, 2001
Creator: McGinnis, Dave
Partner: UNT Libraries Government Documents Department

Measurement of proton and anti-proton intensities in the Tevatron Collider

Description: This paper describes the techniques used to measure the intensities of the proton (p) and anti-proton ({bar p}) beams in the Tevatron collider. The systems provide simultaneous measurements of the intensity of the 36 proton and 36 antiproton bunches and their longitudinal profiles.
Date: June 4, 2003
Creator: al., Stephen Pordes et
Partner: UNT Libraries Government Documents Department

Antiproton stacking in the Recycler

Description: Possibilities to accumulate antiprotons in the Recycler are considered for three different cases: with current stochastic cooling, with upgraded stochastic cooling and with electron cooling. With stochastic cooling only, even upgraded, Recycler looks hardly useful. However, with electron cooling at its goal parameters and reasonably good vacuum in the Recycler, this machine would be efficient.
Date: June 23, 2003
Creator: Burov, Alexey
Partner: UNT Libraries Government Documents Department

Impedances and beam stability issues of the Fermilab recycler ring

Description: The Fermilab Recycler Ring (permanent magnets) will be built on top of the Fermilab Main Injector sharing the same tunnel; its main function is to recycle the anti-protons after a store in the Tevatron and to provide storage for them after after accumulation and cooling in the Accumulator. Estimates of coupling impedances show domination by space charge. Examination of longitudinal instabilities shows that microwave instability will not occur if there are only N = 2.53 x 10{sup 12} anti-protons in the beam. Longitudinal coupling-bunch instability during injection stacking does not appear possible because of long bunch lengths/short bunch gaps and lack of sharp resonances. Transverse instability, on the other hand, cannot be Landau damped by the momentum spread in the beam, but it can be cured by a small spread in the betatron tunes (either from space charge or an octupole).
Date: April 1, 1996
Creator: Ng, King-Yuen
Partner: UNT Libraries Government Documents Department

Gated current integrator for the beam in the RR barrier buckets

Description: At the Fermilab Recycler Ring (RR), the antiproton (pbar) beam will be stored azimuthally in different segments created by barrier buckets. The beam in each segment may have widely varying intensities. They have developed a gated integrator system to measure the beam intensity in each of the barrier bucket. Here they discuss the design of the system and the results of beam measurements using the integrator.
Date: June 10, 2003
Creator: Cadorn, A.; Bhat, C. & Crisp, J.
Partner: UNT Libraries Government Documents Department

Performance of antiproton injection and extraction transfer lines of the Recycler Ring at Fermilab

Description: The Recycler Ring, an 8 GeV antiproton accumulator, is being commissioned at Fermilab. Antiproton transfers in and out of the Recycler Ring take place through two transfer lines connecting the Recycler to the Main Injector. Transfer line layout and operation of beam transfers will be described. Particular attention has been paid to injection mismatch effects, in order to limit emittance growth during transfers. A considerable improvement has been achieved by removing vacuum windows, previously present in both transfer lines.
Date: June 2, 2003
Creator: al., Alberto Marchionni et
Partner: UNT Libraries Government Documents Department

Tune-Shift Compensation Using the Tevatron Electron Lens

Description: The Tevatron Electron Lens was originally designed to alleviate the tune shift and spread induced in Tevatron antiproton bunches from interactions with the proton bunches. We report recent developments and successful results of such tune-shift compensation. Lifetime measurements are central to our data and the basis of our analysis. Future goals and possible uses for the lens are also discussed.
Date: August 20, 2003
Creator: al., Kip Bishofberger et
Partner: UNT Libraries Government Documents Department

Coupled-bunch instabilities of the Tevatron at Run II

Description: The longitudinal and transverse coupled-bunch instabilities of the Tevatron at Run II are addressed in two scenarios. The first scenario corresponds to the present Run II condition: 36 proton bunches on 36 antiprotons. Each proton bunch contains 1.7 x 10{sup 11} particles with a rms bunch length 60 cm. The second scenario is for the future upgrade when there are 108 proton bunches colliding with 108 antiproton bunches. Each proton bunch contains 2.7 x 10{sup 11} particles with a rms bunch length 50 cm. The analysis shows that the growth rates of transverse coupled-bunch instabilities are slow and will be damped by a small betatron tune spread. On the other hand, growth rates of longitudinal coupled-bunch instabilities will be fast especially for the 108-by-108 scenario.
Date: March 6, 2003
Creator: Ng, K. Y.
Partner: UNT Libraries Government Documents Department