Concept design for an ERL based light source - the Femto-Science Factory (FSF)

ERL design and simulation group: Accelerator and development (ARD)

The ERL design and simulation group, G-NSIMU, participates in the Helmholtz Research Program 'Matter and Technology' on the topic 'Accelerator Research and Development'. As subtopic the group investigates ST3 'Picosecond and Femtosecond Electron and Photon Beams'.

ST3 'Picosecond and Femtosecond Electron and Photon Beams'.

The study focuses on a concept design for a light source the Femto-Science Factory (FSF) intending to essentially improve on the 3rd generation machines.

  • Advanced photon sources development
  • Custom beams bunch shape manipulation
  • Short bunches in Multi-turn ERL accelerators
  • Incoherent and Coherent Radiation effects

In order to match the expectations of the user environment, the Femto-Science-Factory intends to offer two interchangeable modes. A low emittance high brilliance mode will operate in conjunction with a short pulse mode.

Particle tracking simulations using realistic beams.


The first mode relies heavily on the optimisation of compensation schemes in the injector and low energy sections where space charge effects tend to dominate. The higher energy optic looks to suppress high order aberrations and radiation effects which again lead to emittance growth. For this mode it is foreseen that only subtle beam compression in the picosecond range is necessary for the producing high brilliance beams.

Off crest acceleration in the split linacs and alternative longitudinal dispersive optic in the high energy Arc sections will provide users with sub-picosecond pulses. A telescopic bunch compression scheme is under investigation that looks to remove the correlated energy spread in the beam using asymmetric off-crest acceleration, resulting in a shorter bunch with lower energy spread compared to present 3rd generation machines.

The group is also dedicated to other subtopics including high current beam investigations, magnet optic design to suppress feed back related beam break up instabilities and optimum multi-stage injection schemes. Please refer to our webpage and the links for more information and our recent publications.