In 1999/2000 a pre-study was made to set the goals for this project. The actual project start of PROSCAN was in autumn of the year 2000. In what is now called NA-Hall, a medical cyclotron was installed in close proximity of the already existing Gantry, predestinated to its specific application. The cyclotron was acquired in May 2001. PSI decided, after an extensive evaluation, in favour of the superconducting 250 MeV-Cyclotron by ACCEL Instruments GmbH (nowadays called Varian Medical Systems). This cyclotron meets the ambitious demands set by PSI and provides the beam throughout the whole year to the proton therapy facility for the treatment of deep lying tumors since 2007.

Design Parameters COMET (PROSCAN) value
Diameter 3.175m
Height 1.38m
Weight ~90t
Magnetic field 2.4 bis 3 Tesla
Energy 250 MeV
Intensity 1 bis 850nA
Turns 630