18 Feb 2019





​SwissFEL facility at the Paul Scherrer Institute, Switzerland. The linear accelerator delivers electron beam energies up to 6 GeV to undulator sections producing FEL light in the X-ray spectral range. 


SwissFEL is a hard X-ray FEL facility under construction at the Paul Scherrer Institute in Villigen, Switzerland. This user facility will produce X-ray pulses greater than 12 keV in energy with pulse durations as short as 20 fs; these will provide critical insight to researchers in a multitude of fields including atomic and molecular physics, materials science and technology applications.

The STFC has been involved in the development of SwissFEL from 2011 and has carried out a number of work packages that have influenced the design of the machine. This has included the design and construction of the laser heater undulator – a vital part of the accelerator which is used to overcome microbunching instabilities in the injector. SwissFEL have also made changes to the Athos FEL to test novel FEL schemes proposed by MARS group at ASTeC. The primary focus of ASTeC during 2016 has been on assisting SwissFEL staff in the commissioning of the accelerator. 

SwissFEL commissioning started in summer 2016 with the participation of ASTeC staff members from October 2016 onwards. STFC staff were present during first beam transmission through the machine. Within a short period of the start of commissioning, the SwissFEL team successfully transmitted beam and in December 2016 observed FEL lasing in the undulator line for the first time. STFC staff were able to obtain first-hand knowledge of the accelerator’s control system and the high-level software applications used for setting the beam; this included characterisation of beam properties such as emittance, and beam optics and orbit setting. Participation is providing a unique opportunity to STFC staff to gain valuable experience on a hard X-ray FEL facility and this collaborative activity is expected to continue in future years. 

On 5th December 2016 the Paul Scherrer Institute held an inauguration ceremony for SwissFEL, with Johann N. Schneider-Ammann, President of the Swiss Confederation, in attendance. During the ceremony, Joël Mesot, Director of the PSI, took the opportunity to publicly thank Daresbury Laboratory for their very significant contributions to the project. Jim Clarke (ASTeC), who has led the STFC-PSI collaboration for the UK, represented STFC at the inauguration event. 


ELI-NP: Joe Herbert​ 
SwissFEL: Deepa Angal-Kalinin​ 

Contact: Keeley-Adamson, Michelle (STFC,DL,AST)