Heavy ion cyclotrons development at JINR

After considering various possibilities of producing intense heavy ion beams with energies of up to 10 MeV/amu and even 100 MeV/amu now we have given preference to the cyclotron method. During more than 20 years this trend has been pursued at our Institute, covering a wide range of studies at the existing accelerators, the development of high-charge state ion sources, the formation of magnetic fields, tests of different systems for beam extraction, etc. At the Laboratory of Nuclear Reactions three heavy-ion cyclotrons are presently in operation which produce beams for physics experiments (the U200, the U300 and the U400) and one cyclotron specially constructed for applied purposes and put into operation in 1985. (author)