Automatic tuning of Free Electron Lasers

Existing FEL facilities often suffer from stability issues: so electron orbit, transverse electron optics, electron bunch compression and other parameters have to be readjusted often to account for drifts in performance of various components. The tuning procedures typically employed in operation are often manual and lengthy. We have been developing a combination of model-free and model-based automatic tuning methods to meet the needs of present and upcoming XFEL facilities. Our approach has been implemented at FLASH \cite{flash} to achieve automatic SASE tuning using empirical control of orbit, electron optics and bunch compression. In this paper we describe our approach to empirical tuning, the software which implements it, and the results of using it at FLASH. We also discuss the potential of using machine learning and model-based techniques in tuning methods

Fitting Algorithms for Optical and Beam Parameters in Transfer Lines with Application to the LHC Injection Line T12

As part of the commissioning with beam of the transfer line TI2 and TI8 from the SPS to the LHC [1], a series of optics measurements has been conducted. The paper presents the results in terms of Twiss parameters (including the dispersion), emittance and momentum spread obtained from the combination of trajectory and beam profile measurements. Profiting from the redundancy of monitors, there is a possibility of applying different fitting algorithms to retrieve beam parameters and to extract information on the optics of the line. The results from the different fit methods applied to the data will be compared with the expected values and cross-checked with independent measurements

The BDSIM Toolkit

This report is a description of the BDSIM toolkit based on the User's Manual for the v0.1 version