Speaker
Dr
Benoit Bolzon
(CERN)
Description
At the CLIC Test Facility 3 (CTF3), beam imaging systems rely mostly on the use of Optical Transition Radiation screens. Nevertheless for low beam energies or reduced beam intensities, OTR screens are replaced by ceramic and yag screens. Contrarily to fluorescent screens, which emit light isotropically, transition radiation has very narrow emission cone with a width inversely proportional to the beam energy. Imaging system using OTR screens will then suffer from vignetting effect, which alters beam size measurement depending on the beam size, the beam energy and on the angular acceptance of the optical system. This paper presents an experimental study of beam imaging system performed on CTF3 at different beam energies using different type of screens. The performance of classical high-reflectivity OTR screens are compared to parabolic and diffusive OTR screens.
Author
Dr
Benoit Bolzon
(CERN)
