Exploratory Orbit Analysis of Tevatron Helical Upgrade: 1. A First Look.

摘要

A key feature of the Tevatron upgrade is the placement of proton and anti-proton bunches on the branches of a double helix which winds around the current closed orbit. Electrostatic separators will transfer the bunches on and off the double helix so that they experience head-on collisions only at the experimental areas, B0 and D0, all other encounters occurring at large transverse separation. In this way the number of bunches, and the luminosity, can be increased without a proportional growth in the beam-beam tune shift. The scenario raises a number of beam dynamics issues, especially (a) the consequences of sampling magnetic fields far from the magnets' center lines, and (b) the effects of the long-range beam-beam interaction. This report presents the results of calculations and simulations done to date to explore (b); a Fermilab team have been studying (a), both experimentally and theoretically, but we shall not review those efforts here. 9 refs., 17 figs.