Undulator Wakefield Measurement in the Aramis Beamline

Your tasks

In SwissFEL at PSI we are injecting relativistic electrons into the periodic magnetic field of an undulator to generate coherent emission of photons in the X-ray regime. For best performance the field strength of the undulator has to be maximized with results in a very narrow gap for the electrons to pass through. This narrow aperture of the SwissFEL vacuum chamber leads to a self-interaction of the electron bunch, passing through the vacuum chamber, called wakefields. They cause a change in the electrons energy, dependent on their position within the bunch. This "temporal" information can be measured by tilting the beam with dispersion, where the transverse position correlates with the particle energy. If the beam is tilted in one plane before the undulator and then in the other plane after it, any deviation from a linear correlation can be attributed to the wakefield potential. If the beam has a well-defined energy chirp it allows then for a temporal reconstruction of this wake potential.

The project consists of setting up SwissFEL for the large bandwidth mode, leaking out dispersion and record the electron distribution for various gaps of the undulator. The results are then benchmarked with the theoretical wakefield model.

Your profile

  • You study in physics, engineering, or a similar field (minimum 4 semesters)
  • You have not yet completed your Master’s thesis
  • You have an interest in developing new instruments and measurement methods
  • You are open-minded, communicative, and you enjoy working in an international team

We offer

Our institution is based on an interdisciplinary, innovative and dynamic collaboration.

The contract will be limited to 3 months.

For further information, please contact Dr Sven Reiche, phone +41 56 310 51 19.

Please submit your application online for the position as a Trainee (index no. 8122-T1).

Paul Scherrer Institut, Human Resources Management, Patrizia Meister, 5232 Villigen PSI, Switzerland