The Paul Scherrer Institute PSI is the largest research institute for natural and engineering sciences within Switzerland. We perform cutting-edge research in the fields of future technologies, energy and climate, health innovation and fundamentals of nature. By performing fundamental and applied research, we work on sustainable solutions for major challenges facing society, science and economy. PSI is committed to the training of future generations. Therefore, about one quarter of our staff are post-docs, post-graduates or apprentices. Altogether, PSI employs 2300 people.

In the SLS2 storage-ring, electron bunches travel almost at speed of light and emit light at bending-magnets and undulators. The RF system of the SLS2 storage-ring restores the energy with four 500MHz Radio Frequency RF cavities and stabilizes the electrons longitudinally. The passive, superconducting third-harmonic cavity helps to lengthen the bunches and to increase the beam-lifetime. 

Amplitude- and phase noise on the 500MHz main cavities can affect the beam-quality, like the energy and energy spread. Therefore, the signal-path, amplifiers and feedback system should be characterized and optimized. 

On the other hand, controlled amplitude- and phase modulation can be used to reduce transient beam-loading and intra-beam scattering. It can also be used to measure the beam-response and potentially also lead to energy-spread oscillations with minima lower than the natural energy spread. 

In the PSI Center for Accelerator Science and Engineering we offer a

Master Thesis Placement in system-identification of the SLS2 storage-ring RF and analysis of the electron beam-response to RF-modulation

Your tasks

This project is divided into two core and one optional advanced part: 
  1. Core tasks:
    a. model the RF-system, measure the system characteristics at the teststand and at the storage-ring with stored electron beam, improve model and parameter.
    b. Include RF-modulation, harmonic cavity and second order momentum compaction factor into the Hamiltonian of synchrotron motion and analyze the evolution of the RF-bucket. Try to reduce transient beam-loading effects.
  2. Advanced task (for experienced students): Evaluate the potential of rf-modulation to reduce the energy-spread (minima of the oscillation) in synchrotrons.

Your profile

  • Foundational knowledge of calculus, linear algebra, and complex numbers
  • Proficiency in writing simple scripts in Python or Matlab
  • Interest in RF-systems for synchrotrons
  • General interest in particle accelerators

We offer

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

The maximum duration will be around 6 months, preferably starting in early 2026. 

Please note: The master’s thesis does not involve employment at PSI.

For further information, please contact Dr Lukas Stingelin, phone +41 56 310 58 41. 

Please submit your application online for the master thesis project (index no. 8413-25852).

Paul Scherrer Institute, Human Resources Management, Lara Essig, 5232 Villigen PSI, Switzerland
Apply now