Scintillating Fibers used as Profile Monitors for the CNAO HEBT Lines

The CNAO (Centro Nazionale di Adroterapia Oncologica) Foundation is the first Italian center for deep hadrontherapy with Protons and Carbon Ions. Several beam monitors exploiting the scintillation process have been designed to check the beam quality in the extraction lines, in order to guarantee patients safety. The SFH (Scintillating Fibers Harp), the QPM (Qualification Profile Monitor), and the SFP (Scintillating Fibers plus Photodiodes) are made up by two orthogonal scintillating fibers harps with not dead area for the horizontal and the vertical beam profiles measurement. The QPM and the SFH are both installed on the beam line and they use a CCD camera for the signal acquisition. The SFP is a SFH upgrade project aimed to replace the camera with two Photodiodes arrays coupled to the fibers in vacuum. The WD (Watch Dog) detector, not already installed, has been designed to check the beam position through the intensity of the beam tails. It uses two couples of scintillating fibers displaced transversally to the beam direction, coupled to four APDs (Avalanche Photodiodes). This work describes the beam detectors, their achieved performances and the most recent beam measurements.