Fermilab, Batavia
Funding: Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
We present the strategy which has been used recently to optimize integrated luminosity at the Fermilab Tevatron proton-antiproton collider. We use a relatively simple model where we keep the proton intensity fixed, use parameters from fits to the luminosity decay of recent stores as a function of initial antiproton intensity (stash size), and vary the stash size to optimize the integrated luminosity per week. The model assumes a fixed rate of antiproton production, that a store is terminated as soon as the target stash size for the next store is reached, and that the only downtime is due to store turn-around time. An optimal range of stash size is predicted. Since the start of Tevatron operations based on this procedure we have seen an improvement of approximately 35% in integrated luminosity. Other recent operational improvements have been achieved by decreasing the shot setup time and by reducing beam-beam effects by making the proton and antiproton brightnesses more compatible , for example by scraping protons to smaller emittances.
Fermilab, Batavia
Muons, Inc, Batavia
Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The use of existing Fermilab facilities to provide beams for two muon experiments –- the Muon to Electron Conversion Experiment (Mu2e) and the Muon g-2 Experiment –- is under consideration. Plans are being pursued to be able to perform these experiments following the completion of the Tevatron Collider Run II with no impact to the on-going Main Injector neutrino program by using spare Booster cycles to provide 8.9 GeV/c protons on target. Utilizing the beam lines and storage rings used today for antiproton accumulation, beams can be prepared for these experiments with minimal disruption, reconfiguration or expansion of the Fermilab accelerator infrastructure. The proposed operational scenarios and required alterations to the complex are described.
Fermilab, Batavia
Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The recent record-setting performance of the Fermilab Tevatron is the culmination of a long series of efforts to optimize the many parameters that go into generating integrated luminosity for the colliding beams experiments. While several complex numerical computer models exist that are used to help optimize the performance of the Tevatron collider program, here we take an analytical approach in an attempt to illustrate the most fundamental aspects of integrating luminosity in the Tevatron. The essential features, such as weekly integrated luminosity and store length optimization, can be understood in a transparent way from basic operational parameters such as antiproton stacking rate and observed beam emittance growth rates in the Tevatron. Comparisons of the analytical model with operational data are provided.
BNL, Upton, Long Island, New York
Fermilab, Batavia
The University of Texas at Austin, Austin, Texas
An AC dipole magnet produces a sinusoidally oscillating dipole field with frequency close to betatron frequency and excites large sustained oscillations of beam particles circulating in a synchrotron. Observation of such oscillations with beam-position-monitors allows direct measurements of a synchrotron's nonlinear parameters. This paper presents experimental studies to measure effects of sextupole and octupole fields, such as tune dependence on amplitude and resonance driving terms, performed in the Fermilab Tevatron using an AC dipole.