The JINR U-400 Isochronous Heavy Ion Cyclotron

The main data on the 4-meter isochronous cyclotron (the U-400) currently under construction at the Joint Institute for Nuclear Research at Dubna are presented. The accelerator is designed to produce intense heavy-ion beams with a maximum energy E = 725 q2/A MeV and an intensity of 1014 - 1011 part/s in a wide range of elements through xenon (3 ?? A/q ?? 12). A brief description of the design features and parameters of the facility is given. The U-400 Isochronous Heavy Ion Cyclotron currently under construction at the JINR Laboratory of Nuclear Reactions is a development of the multiply-charged ion-acceleration technique used at this Laboratory.1,2 In comparison with the two accelerators operated at the Laboratory, the new cyclotron will open up wider possibilities for solving some fundamental and applied problems of modern physics. The Laboratory´s principal accelerator, the U-300, is a classical cyclotron with a pole diameter of 310 cm, which is used to carry out numerous experiments in different fields of nuclear physics. This cyclotron provides the acceleration of 11B2+, 12C2+, 14N2+, 15N3+, 16,18O3+ 20,22Ne4+ 28Si5+, 31P5+ and 40Ar6,7,8+ ions with the A/q parameter of 5 to 7, where A is the mass number and q is the charge of the ion accelerated. The energy of the accelerated ions is equal to E = 250 q2/A MeV.