• S. Krinsky, J. Bengtsson, J. S. Berg, M. Blaskiewicz, A. Blednykh, W. Guo, N. Malitsky, C. Montag, B. Podobedov, J. Rose, N. A. Towne, L.-H. Yu
  BNL, Upton, Long Island, New York
• F. Wang
  MIT, Middleton, Massachusetts

A new high-brightness synchrotron light source (NSLS-II) is under design at BNL. The 3-GeV NSLS-II storage ring has a double-bend achromatic lattice with damping wigglers installed in zero-dispersion straights to reduce the emittance below 1nm. In this note, we present an overview of the impact of collective effects upon the performance of the storage ring. Subjects discussed include Touschek lifetime, intra-beam scattering, instability thresholds due to ring impedance, and use of a third-harmonic Landau cavity.

• J. S. Berg, A. G. Ruggiero
  BNL, Upton, Long Island, New York
• S. R. Koscielniak
  TRIUMF, Vancouver
• S. Machida
  STFC/RAL/ASTeC, Chilton, Didcot, Oxon

EMMA is a 10 to 20 MeV electron ring designed to test our understanding of beam dynamics in a relativistic linear non-scaling fixed field alternating gradient accelerator (FFAG). This paper describes the design of the EMMA lattice. We begin with a description of the experimental goals that impact the lattice design. We then describe what motivated the choice for the basic lattice parameters, such as the type of cells, the number of cells, and the RF frequency. We next list the different configurations that we wish to operate the machine in so as to accomplish our experimental goals. Finally, we enumerate the detailed lattice parameters, showing how these parameters result from the various lattice configurations.

• R. B. Palmer, J. S. Berg, R. C. Fernow, J. C. Gallardo, H. G. Kirk
  BNL, Upton, Long Island, New York
• Y. Alexahin, D. V. Neuffer
  Fermilab, Batavia, Illinois
• S. A. Kahn
  Muons, Inc, Batavia
• D. J. Summers
  UMiss, University, Mississippi

We propose a complete scheme for cooling a muon beam for a muon collider. We first outline the parameters required for a multi-TeV muon collider. The cooling scheme starts with the front end of the Study 2a proposed Neutrino Factory. This yields bunch trains of both muon signs. Emittance exchange cooling in upward climbing helical lattices then reduces the longitudinal emittance until it becomes possible to combine the trains into single bunches, one of each sign. Further cooling is now possible in emittance exchange cooling rings. Final cooling to the required parameters is achieved in 50 T solenoids that use high temperature superconductor. Preliminary simulations of each element will be presented.

• D. Trbojevic, I. Ben-Zvi, J. S. Berg, M. Blaskiewicz, V. Litvinenko, W. W. MacKay, V. Ptitsyn, T. Roser, A. G. Ruggiero
  BNL, Upton, Long Island, New York

Acceleration of electrons up to 10 GeV for a future electron-ion collider eRHIC (Relativistic Heavy Ion Collider) could be performed with the energy recovery linac with multiple passes. An energy recovery scheme is required if a superconducting linac is used for acceleration. We report on an attempt to make a combination of a multi-pass linac with non-scaling Fixed Field Alternating Gradient (NS-FFAG) arcs. Two NS-FFAG arcs would allow electrons to pass through the same structure with different energies. The beam will be accelerated by the superconducting linac at the top of the sine function, and returned to the front of the linac by the non-scaling FFAG. This process is repeated until the total energy of 10 GeV is reached. After collisions the beam is brought back by the NS-FFAG and decelerated before being dumped.