Analytical considerations for linear and nonlinear optimization of the theoretical minimum emittance cells: Application to the Compact Linear Collider predamping rings

Abstract

The theoretical minimum emittance cells are the optimal configurations for achieving the absolute minimum emittance, if specific optics constraints are satisfied at the middle of the cell's dipole.Linear lattice design options based on an analytical approach for the theoretical minimum emittance cells are presented in this paper. In particular the parametrization of the quadrupole strengths and optics functions with respect to the emittance and drift lengths is derived. A multi-parametric space can be then created with all the cell parameters, from which one can chose any of them to be optimized. An application of this approach are finally presented for the linear and non-linear optimization of the CLIC Pre-damping rings.

Design and Principles of Linear Accelerators and Colliders

“…For CLIC, the large input emittance for the positron beam and the high repetition rate necessitates a two-stage beam damping, with a pre-damping ring [94]. For ILC, there is no pre-damping stage and the DRs need a large acceptance for the injected beams, especially for positrons.…”

Emittance reduction with variable bending magnet strengths: Analytical optics considerations and application to the Compact Linear Collider damping ring design

“…Due to their compactness and the very small emittance these cells reach, they are preferred for some ring designs. The performance of these cells was previously studied analytically for the case of uniform dipoles [1]. In what follows, a further minimization of the TME cell emittance when using longitudinally variable bends instead of uniform dipoles is described in detail.…”

“…Extending the analytical approach for the TME cells with uniform dipoles [1], the parametrization of the quadrupole strengths and optics functions with respect to the drift lengths and the emittance is derived for a non-uniform dipole. The strong focusing needed for accomplishing the TME conditions results in cells with high chromaticities.…”

Magnet Lattice Optimization for Novosibirsk Fourth Generation Light Source SKIF

“…This configuration received the name TME (Theoretical Minimum Emittance) [2][3][4][5][6] and factor F is…”