Study of Beam Parameters of 240-CM Isochronous Cyclotron

For two years beam parameter investigations have been carried out at the Kiev cyclotron for the extraction process and the beam transport system. The data obtained show that high quality beam is obtained with 0.1% accelerating voltage stabilization and shape selection of the isochronous magnetic field which limits phase shift to ±5°. The system for radial beam phase selection provides control of bunch phase duration within 5°-25°. In this case the radial oscillation amplitude does not exceed 2-3 mm and extraction efficiency from the cyclotron is about 70%. The measured beam emittance at the accelerator output is 20 mm-mrad. for vertical motion and 28 mm-mrad. for horizontal motion. Energy spread in the extracted beam is less than the energy gain per turn and is about 0.3%. The complete beam transport system is in use and provides beam without losses to any of six experimental rooms.