Prospectus for an Electron Cooling System for the Recycler

The Recycler ring was added to the Main Injector (MI) project in 1997 as means to recover the antiprotons remaining at the end of Tevatron stores and to serve as a second stage accumulator to raise the maximum stack current. This report describes an electron cooling system with substantially higher stack capacity than the Recycler stochastic cooling system which could be brought into operation toward the end of Run II. It is the major component of a program to double the design Run II luminosity and should have a positive effect on integrated luminosity soon after turnon. The upgrade potential is intended to meet the longer term needs of the Laboratory’s luminosity upgrade program. The current experience with electron cooling is discussed to provide the rationale for the choice of design parameters and to make clear the needs for additional development work. Both analytical and numerical development of the theory has been pursued to confirm that the limits in principle are well beyond foreseen need. The specific hardware described is not the only realization that has been considered, but it is in some ways the most conservative. The general scheme of using an electrostatic accelerator with high efficiency charge recovery was actively discussed in the 1980’s. Recent developments have served to build confidence in this approach, but, by whatever means realized, a Recycler electron cooling system will require significant extension of current practice. The Prospectus incorporates the ideas and understanding current 15 September 1998. Rapid progress toward a comprehensive development plan at this time means that its details will already differ from ideas now current. Contributors to the Recycler Electron Cooling Design Alexi Burov (Budker Institute) Curtis Crawford Thomas Kroc James MacLachlan, Prospectus editor Sergei Nagaitsev, group leader Charles Schmidt Anotoli Sharapa (Budker Institute) Alexander Shemyakin (Budker Institute) Arden Warner