In this paper we report on a systematic study of antiproton lifetime at the injection energy of 150 GeV in the Tevatron. Our parallel beam-beam model can handle both strong-strong and weak-strong beam-beam collisions with abitrary beam-beam separation and beam distributions. In this study, we have only used the weak-strong capability due to the fact that the antiproton intensity is much smaller than the proton intensity. We have included all 72 long-range beam-beam collisions with a linear transfer map between adjacent collision points and taken into account linear chromaticity. The effects of antiproton emittance, beam-beam separation, proton intensity, and machine chromaticity have been investigated. Initial results show that the antiproton lifetime as a function of the proton intensity from the simulation is in good agreement with that from the experimental measurements. The antiproton lifetime can be significantly improved by increasing the beam separation and by reducing the antiproton emittance.

In this paper, we present a parallel computational tool, BeamBeam3D, developed at Lawrence Berkeley National Laboratory, for strong-strong/strong-weak beam-beam modeling. This tool calculates self-consistently the electromagnetic beam-beam forces for arbitrary distributions during each collision when a strong-strong beam-beam interaction model is used. When a strong-weak model is used, the code has the option of using a Gaussian approximation for the strong beam. BeamBeam3D uses a multiple-slice model, so finite bunch length effects can be studied. The code also includes a Lorentz boost and rotation to treat collisions with finite collision crossing angle. It handles arbitrary closed-orbit separation (static or time dependent) and models long-range beam-beam interactions using a newly developed shifted Green function approach. It can also handle multiple interaction points using externally supplied linear maps between interaction points in the strong-weak model. The code has been used to study beam-beam effects in the RHIC, Tevatron, and LHC. In this paper we will describe the BeamBeam3D code, present example simulations, and describe the code performance.