CLASSE, Ithaca
University of Minnesota, Minneapolis, Minnesota
CESR-LEPP, Ithaca, New York
Cornell University, Department of Physics, Ithaca, New York
Technion, Haifa
In April 2008, we propose to begin operation of the Cornell Electron Storage Ring (CESR) as a test accelerator, CesrTA, for International Linear Collider (ILC) damping ring research. Utilizing 12 damping wigglers, the baseline CesrTA lattice at 2.0 GeV will offer a natural geometric emittance of 2.25 nm. An experimental program has been laid out which focuses on several key areas of damping rings R&D. First we will test vacuum chamber designs to suppress electron cloud growth in the wiggler magnets. Secondly, we will develop correction, tuning and emittance monitoring strategies to achieve vertical emittances of a few picometers. As part of this effort we will validate alignment and survey techniques being developed by the Linear Collider Alignment and Survey group (LiCAS) for curved tunnel applications. After achieving ultra-low emittance, we intend to explore the impact of the electron cloud, the fast ion instability and other beam dynamics effects on ultra-low emittance beams. Finally, we plan to test various technical systems required for the ILC damping rings. This paper provides an update on conceptual design issues for CesrTA and describes the experimental program in detail.
CLASSE, Ithaca
The ILC damping rings require wiggler magnets with large physical aperture and with excellent field quality to maintain the dynamic aperture of the rings. We consider two possible designs derived from the wigglers presently in operation at the Cornell Electron Storage Ring. Design optimization has been performed based on detailed tracking calculations of dynamic aperture and tune footprint in a full model of the damping ring. Results of finite-element modeling, transfer functions, and the accuracy of analytic models of the wiggler field will be discussed.