Speaker
Mathias Vogt
(Deutsches Elektronen-Synchrotron)
Description
Within the FLASH 2020+ upgrade project of the FLASH facility in Hamburg, the original FLASH beamline (FLASH1) will be completely remodelled and equipped with variable gap APPLE-III undulators, capable of controlling the polarization state of the FEL radiation.In the course of enhancing the operability of FLASH, the influence of the variable undulator focusing in both planes will be compensated by an automatic correction algorithm.The aim is to maintain a stable optics while minimizing optical changes.
In this article, we discuss the basic stability concepts of a ``FUDU'' (focussing quadrupole, undulator, defocussing quadrupole, undulator) lattice, and compare several analytical approximations and numerical approaches.
Authors
Bart Faatz
(Shanghai Advanced Research Institute)
Johann Zemella
(Deutsches Elektronen-Synchrotron)
Mathias Vogt
(Deutsches Elektronen-Synchrotron)
Zhichu Chen
(Shanghai Synchrotron Radiation Facility)
