Laboratory link : https://irfu.cea.fr/dacm/
More : https://irfu.cea.fr/dedip/index.php
Ion accelerators, including protons, at very high intensity (> 50 mA), find numerous applications in various fields of nuclear physics or material characterization for medical, nuclear, and other applications. The Department of Accelerators, Cryogenics, and Magnetism (DACM) at CEA-Saclay specializes in the design and realization of very high-intensity ion sources.
With the increase in beam current, these sources become increasingly complex. Therefore, mastering the quality of the beam becomes critical to limit power deposition and the activation of accelerator elements. To better understand and describe this beam, it is necessary to determine its 4D emittance, which includes both the geometric shape of the beam and its trajectory. The device used for this measurement is called a 4D emittance meter.
Such a device based on a scintillator has already been designed and tested. This scintillator converts a portion of the beam into an image, which is then captured by a camera. Unfortunately, while this technology is functional at high energy, it is not suitable at the source outlet, at low energy, as the scintillation layers are quickly damaged by the ion flux.
The charge reading method proposed in this thesis is novel and benefits from the synergy between particle detector research for high-energy physics and proton source research. Instead of using a camera for reading, the idea is to measure, from a PCB placed directly in the beam, the current carried by the ions. This method allows reading this current at several thousand positions to obtain the 4D emittance. The fast acquisition system will also allow observing the temporal variation of the emittance during the start-up and shut-down phases of the source.
This device will be used for analyzing the beam generated by the ALISES sources developped by the laboratory.