Multi-objective direct optimization of dynamic acceptance and lifetime for potential upgrades of the Advanced Photon Source.

Abstract

The Advanced Photon Source (APS) is a 7 GeV storage ring light source that has been in operation for well over a decade. In the near future, the ring may be upgraded, including changes to the lattice such as provision of several long straight sections (LSS). Because APS beamlines are nearly fully built out, we have limited freedom to place LSSs in a symmetric fashion. Arbitrarilyplaced LSSs will drastically reduce the symmetry of the optics and would typically be considered unworkable. We apply a recently-developed multi-objective direct optimization technique that relies on particle tracking to compute the dynamic aperture and Touschek lifetime. We show that this technique is able to tune sextupole strengths and select the working point in such a way as to recover the dynamic and momentum acceptances. We also show the results of experimental tests of lattices developed using these techniques.

Progress Toward an Ultimate Storage Ring Light Source

“…Subsequently, a more general method [12] based on minimization of resonance driving terms (RDTs) was adopted, leading to a gradual increase in the complexity and sophistication of sextupole schemes. More recently, as computational capabilities have increased, direct methods-i.e., methods based on particle tracking-have emerged [13][14][15][16][17].…”

Symmetric achromatic low-beta collider interaction region design concept

“…This provides a guideline that the DA can be further enhanced by considering and optimizing the 1st-, 2nd-, and even higher-order amplitude-dependent effects. One possibility for future studies is to use a genetic algorithm to optimize the DA directly by simultaneously adjusting multiple sextupole and octupole families [21]. Note that magnet errors are not included in the above simulations.…”

Optimizing the lattice design of a diffraction-limited storage ring with a rational combination of particle swarm and genetic algorithms

“…Moreover, the optics is matched to form a I transportation between each pair of sextupoles to cancel most of the nonlinearities induced by the sextupoles. Due to these advantages, the hybrid MBA lattice has been adopted in many projects, e.g., ESRF-II [14], Sirius [7] and APS-U [15].…”