News and events
- 2026/07/01: Version of record of EAAC proceedings "SHARP: A compact focusing system for medical applications using a diverging plasma lens" are online
- 2026/04/09: We are looking for master student(s)!
- 2026/02/23: arXiv version of EAAC proceedings available. Also poster.
- 2025/03/26: Master thesis Elisabeth Rød-Lindberg is published on DUO
- 2025/01/31: PhD position available, application deadline Feb. 28th.
- 2025/01/20: MSc exam, Elisabeth Rød-Lindberg
Project goals and description
In order to focus a particle beam sharply to a small spot and with a large opening angle, the beam must be enlarged before entering the final focus quadrupoles. To do this in a compact aparatus while preserving the beam quality needed for proper focusing is challenging when only using conventional quadrupole magnets.
In this project we will apply an Active Plasma Lens (APL) for quickly enlarging the beam, before focusing it with a set of quadrupole magnets. This produces a very sharp focal point as illustrated in the figure below, which can be moved and tuned by changing the current in the magnets. The use of these makes it possible to create a compact system that concentrates the beam in the desired target (e.g. a tumor), while avoiding concentrations of beam and thus dose while passing through healthy tissue on the way to the target.
Active plasma lenses are a new type of magnetic lens under development for enabling the next generation colliders for particle physics. In a plasma lens the beam is passing through a rarefied gas, and a strong electrical current is simultaneously passed through it. This current creates a magnetic field which works as an optical lens for the beam. Because the current and the beam are in the same location, the field seen by the beam has a different shape than what is possible with conventional technology. This makes it possible for the system to focus more precisely than when only using conventional magnets.
A prototype of this system will be tested at CERN’s CLEAR facility (CERN Linear Electron Accelerator for Research). CLEAR is used for testing of technology for particle accelerators, and to explore the effect of various types of irradiation on biological samples. We have here already built an experiment for testing plasma lenses, that will be used to test this concept under various conditions.
The CLEAR testing will be done with electrons, however proton therapy is regarded as a very precise technology for particle therapy, and in 2025 two centers for this will open in Norway. Towards the end of the project, we will look for possibilities to make the SHARP technology available for researchers working on biological effects of radiation therapy here.
