The Tohoku University 680 Model Cyclotron and Facility

The acceptance test of the 680 model cyclotron at the Cyclotron Radioisotope Center of Tohoku University was completed in December, 1977. The fundamental design is that of CGR-MeV, France, and the machine was constructed by Sumitomo Heavy Industries. Based upon the experience of the first machine of this model built at CNRS (Orleans, France), some modifications to boost proton energy from 38 MeV to 40 MeV were carried out. During the acceptance test, an emittance measurement at 40 MeV proton energy with 40 μA extracted current was conducted in order to have accurate information for delivery of beam through the beam transport. The emittance was 22 and 31 mm mrad at the X and Y axes, respectively. A simple beam energy resolution experiment also was carried out, namely the measurement of elastic scattered particles from a thin foil of iron, using an SSD.