An X-ray free-electron laser with a highly configurable undulator and integrated chicanes for tailored pulse properties
Eduard Prat, André Al Haddad, Christopher Arrell, Sven Augustin, Marco Boll, Christoph Bostedt, Marco Calvi, A. L. Cavalieri, P. Craievich, A. Dax, Philipp Dijkstal, Eugenio Ferrari, R. Follath, R. Ganter, Zheqiao Geng, Nicole Hiller, Martin Huppert, R. Ischebeck, Pavle Juranić, Christoph Kittel, Gregor Knopp, Alexander Malyzhenkov, F. Marcellini, Stefan Neppl, S. Reiche, Nicholas Sammut, Thomas Schietinger, Thomas M. Schmidt, Kirsten Schnorr, A. Trisorio, C. Vicario, D. Voulot, Guanglei Wang, Tobias Weilbach
Abstract
X-ray free-electron lasers (FELs) are state-of-the-art scientific tools capable to study matter on the scale of atomic processes. Since the initial operation of X-ray FELs more than a decade ago, several facilities with upgraded performance have been put in operation. Here we present the first lasing results of Athos, the soft X-ray FEL beamline of SwissFEL at the Paul Scherrer Institute in Switzerland. Athos features an undulator layout based on short APPLE-X modules providing full polarisation control, interleaved with small magnetic chicanes. This versatile configuration allows for many operational modes, giving control over many FEL properties. We show, for example, a 35% reduction of the required undulator length to achieve FEL saturation with respect to standard undulator configurations. We also demonstrate the generation of more powerful pulses than the ones obtained in typical undulators. Athos represents a fundamental step forward in the design of FEL facilities, creating opportunities in FEL-based sciences.