Fermilab, Batavia
Extensive work has been done to create an accurate model of beam dynamics at the Fermilab Tevatron. This talk will present validation and results from the development of a simulation of the machine including multiple beam dynamics effects. The essential features of the simulation include a fully 3D strong-strong beam-beam particle-in-cell Poisson solver, interactions among multiple bunches and both head-on and long-range beam-beam collisions, coupled linear optics and helical trajectory consistent with beam orbit measurements, chromaticity and resistive wall impedance. The individual physical processes are validated against measured data where possible, and analytic calculations elsewhere. The simulation result discussion will focus on the effects of increasing beam intensity with single and multiple bunches on the impedance of the beams.
Fermilab, Batavia
The proposed Mu2e experiment will present a number of challenges for the Fermilab accelerator complex. The Accumulator and Debuncher rings of what is currently the antiproton complex will be required to handle proton beams with intensities several orders of magnitude larger than the antiproton beams they now carry, leading to a substantial space-charge tune shift. The protons will be then be extracted from the Debuncher using resonant extraction. We present results from simulations of 3D space charge effects for Mu2e beam parameters, with emphasis on how they affect the resonant extraction process.
Fermilab, Batavia
The Synergia framework has been enhanced to include new Poisson solvers and new collective physics effects. Synergia now includes Sphyraena, a solver suite that provides the ability to handle elliptical beam pipes. Resistive wall effects, including intra- and inter-bunch effects in the presence of multiple bunches are also available. We present an overview of the updates in Synergia, focusing on these developments.
Illinois Institute of Technology, Chicago, Illinois
IIT, Chicago, Illinois
Fermilab, Batavia
Funding: This work supported by NSF grant No. 0237162, and DOE SCIentific Discovery through Advanced Computing: Accelerator science and simulation DE-PS02-07ER07-09
The FNAL Booster is a combined-function proton synchrotron with a bunch intensity of ~6·1010 protons; significantly greater than expected in the original design. The injection energy is 400 MeV (gamma factor 1.4), low enough for space charge forces to play a role in beam dynamics. The magnets are used directly as vacuum tanks, so the laminated pole surfaces contribute significantly to impedance. A study of the transverse coupling dependence on beam intensity is presented here. Experimental results are being analyzed using Synergia, a high-fidelity, parallel, fully 3D modeling code that includes both space charge and impedance dynamics. Previously, Synergia has always shown good agreement with experimental data. Our initial studies show that the direct space charge contribution to beam dynamics is too small to account for the increase in the coupling seen experimentally, corroborating analytic results. Parametric studies of the impedance needed to match the measured coupling are being done. Agreement between simulation and experiment should provide an independent measure of the Booster impedance, which has been analytically modeled and calculated elsewhere.