Master Projects

Thanks to the close working contacts with PSI and CERN laboratories the Laboratory of Particle Accelerator Physics can propose several Master thesis on front edge research topics with experimental work in one of this accelerator facilities. There are several topics and continuously changing.

Please do not hesitate and contact Dr T. Pieloni ([email protected]) for more information.

Available Master Projects:

Project Type: Master’s Project

Duration: 6 months

Project description

Located at the Paul Scherrer Institut, a new high power, radio-frequency (RF) test facility for high gradient photoguns is under development. The facility will be the home of two new RF guns, which are designed to be the electron sources for the next generation of particle accelerators. The successful applicant(s) of this Master’s project will work with the primary investigator of this project on the development of a novel field-emission electron source. These field-emission sources aim to simplify the electron source by removing the requirement of a high power laser. The primary task of the candidate will be to assist in the design and realisation of the field-emission cathodes. This will include the electromagnetic (EM) modelling of the cathode(s) and performing detailed particle tracking simulations of the electron beam inside the intense EM fields. Furthermore, the applicant will have the opportunity to perform experimental measurements of the cathode’s performance on the test facility to valid the particle tracking models.

For the update of the Swiss Light Source at PSI, it is planned to make extensive use of different types of magnets, not based on electromagnetism but on permanent magnet materials instead. However, available permanent magnet materials usually have a magnetization, which is varying with temperature. To counter this effect of temperature dependency and to build magnets with a reliable consistency in magnetic field over a wide range of temperatures, materials with temperature dependent permeability can be used to either enhance of reduce the effective field of a magnet. With the right design, such a material can be used to cancel the temperature dependency of permanent magnet materials over the operating temperature range in a particle accelerator such as SLS.

In the design process of such magnet systems, it is crucial to have reliable temperature dependent material data on hand. Since such data is not always available from reliable sources, the topic of this master thesis is the design, construction and evaluation of a measurement system for determining the magnetic permeability of material samples at different temperatures.

The magnetic permeability can be measured by use of an “Epstein Frame”. This measurement technique is standardized and described in DIN EN 60404-2:2009-01.

During the course of this thesis, an “Epstein Frame” should be constructed according to the defined standard, but with the capability of being used in a range of temperatures between 77K and 400K. This requires the selection of suited materials for the task as well as adjustments to the measurement technique and thermal control of the material samples during a measurement.

The outcome of the proposed measurement setup should be verified versus other measurement techniques for determining magnetic permeability, e.g. a vibrating-sample magnetometer (VSM).

PSI is preparing to upgrade its synchrotron X-ray source to the SLS 2.0, which will feature smaller electron beams to generate more coherent X-Rays. In preparation for this, we have set up an X-ray camera to measure the beam size in the present synchrotron. The camera consists of a Fresnel zone plate and an X-ray detector. 
You will characterize this setup in simulations and experimentally, and help understand the capabilities and resolution limits of the device. You will look in particular at the effects of the vacuum window and help us assess whether an in-vacuum setup could offer the superior resolution that we will need for SLS 2.0.
Additionally, you will consider beam size measurements for FCC-ee, a collider with 100 km circumference, which is being designed by an international collaboration lead by CERN. You will evaluate whether an X-ray camera could be considered to measure the beam size in this storage ring.

Within the last 10 years, proton therapy has established itself as a valid treatment option for tumours in radiotherapy.

Large aperture magnets (200-250 mm) producing a magnetic field around 5 T can help improving the treatment. According to these requirements, superconducting magnets are the enabling technology.

The magnet section of PSI already developed a general design for a similar magnet that would now require to be customized.  

Starting from the already existing design, the main tasks related to the aforementioned position are:

  • Magnetic design of a possible superconducting dipole magnet
  • Selection of the most suited superconducting material
  • Thermal and mechanical design of the superconducting magnet.

Description:  Transition crossing is unavoidable in most circular accelerators, and its possible harmful effects are mitigated in several ways, generally by implementing gamma-jump gymnastics. Recently, a beam manipulation technique, based on the use of stable islands, inspired by the idea of Multi-Turn Extraction, has been proposed to cross transition energy. This idea involves generating empty stable islands using sextupoles and octupoles, which have a different transition energy than that of the original closed orbit. The beam will then be kicked into these stable islands just before transition, accelerated, and kicked back to their original path just after transition, so that effectively the particles do not experience the transition crossing. This could be studied for a realistic accelerator lattice of the CERN Super Proton Synchrotron ring in view of a possible experimental test.



The Future Circular Collider for electron-positron collisions (FCC-ee) is one of the main candidates to further study fundamental particle interactions and push constraints on the Standard Model. The FCC-ee will face very challenging obstacles due to its ambitious optics design, energies, and luminosity goals.

To reach the desired luminosity an unprecedented control of the interaction point optics is required. The coupling of vertical and horizontal plane optics can critically cripple the designed optics in the interactin regions and thus greatly affect the luminosity reach. It should therefore be well understood and controlled.

The aim of this project is to explore the causes of coupling, understand its effect on the optics design, and investigate correction schemes. With this project you will dive into the fascinating world of accelerator optics and be able to have a direct impact on the FCC-ee design studies.

While accelerator optics codes have very powerful optimization routines, the design phases of circular accelerators and particle colliders are to this day still greatly reliant on human interference. Optimization algorithms have significantly evolved with the arrival of machine learning techniques and AI. While these new methods are widely used in industry and other scientific fields, they are only recently finding traction in the field of accelerator physics. Still, these applications are more commonly found in accelerator operation and anomaly detection, and the field of accelerator design remains mostly untouched. The aim of this project is to explore novel optimization techniques for the bare bones design of circular particle accelerators. It is a first venture into this field that will help identify challenges and opportunities for more efficient optics designs of future particle accelerators and colliders.

Lepton colliders represent a unique tool for precision particle physics experiments and thus to probe the properties of the fundamental constituents of the universe. While electron-positron colliders tend to become inefficient for energies higher than hundreds of GeV, muons appear as an appealing alternative to collide multi-TeV leptons. Nevertheless, the acceleration of muons raises numerous new challenges with respect to conventional acceleration technologies link to their low lifetime. A novel type of fast acceleration chain was designed featuring dog-bone recycling linear accelerators and fast cycling synchrotrons in which the two beams circulate on the same orbit with opposite velocities, such that they collide several times during the acceleration phase. The student will address the evolution of the transverse distribution of the muon beam along the acceleration chain and in the collider ring. He/she will develop new numerical tools based on an existing framework and use them to study the mechanisms of degradation of the beam quality as well as methods to mitigate them.