CEA
Development of a Novel Beam Profile Monitor Based on Light Emission from Excited Rest Gas Atoms
ESR: Cherry-May Mateo (cherry-may.mateo@cea.fr)
Supervisor: Raphael Gobin (raphael-jean.gobin@cea.fr)
Many accelerator projects make use of high intensity ion beams. These are then used for example for the production of neutrons, at neutrinos factories or in nuclear physics research. The transverse distribution of these beams needs to be accurately known to avoid any unwanted interaction with the vacuum chamber walls and to properly interact with the target.
The power of these beams prevents using intrusive methods since any kind of screen would be rapidly destroyed by the temperature increase. One can rely on the neutral gas present in the vacuum chamber that is excited by the beam. The light emitted by this gas may then be used to obtain a good representation of the beam path.
At CEA a beam profile monitor based on light emission from excited rest gas atoms is being developed. The design of this instrument has been finalized and a prototype setup was already realized. In addition, tomography algorithms are being studied to reconstruct the 2D transverse beam profile observed along different directions. Measurements will then be realized to collect information on specific ion beams and to apply this information for fine tuning of the accelerator.
Development of Beam Diagnostics for IFMIF Accelerator
ESR: Jan Egberts (jan.egberts@cea.fr)
Supervisor: Jacques Marroncle (jacques.marroncle@cea.fr)
Within the framework of the IFMIF-EVEDA1) project, a high-intensity deuteron accelerator prototype will be built and tested at Rokkasho (Japan). The development of non-interceptive diagnostics for such a powerful accelerator (1.125MW) is very challenging, as all monitors have to work in a high radiation environment. Within the frame of this project, a transverse beam profile monitor based on the ionization of the residual gas is being developed and tested in close collaboration with international partners, such as GSI/Germany. Optimization of the monitor’s electric field homogeneity, participation to the electronics design, measurements with beam, as well as a detailed analysis and simulation of the monitor response all form part of the project.
In addition, investigations into beam loss monitors are being carried out. This includes a calibration of the ion chambers with neutrons and γ in the MeV range. Energy loss simulations to define safety margins for the electronics and numerical simulations of expected thermal loads on different detector components complement this project.
1) IFMIF stands for « International Fusion Materials Irradiation Facility », while EVEDA stands for « Engineering Validation and Engineering Design Activity ».