Heavy ion synchrotron - Cooler ring, TARN II

TARN II is a ring with the mean radius of 12.4 m, which can accept the beam with magnetic rigidity up to 7.3 T . m, corresponding to the maximum energies up to 1400 MeV and 500 MeVμ for proton and ions with charge to mass ratio of 12, respectively. Its main magnet system is based on FODO lattice and is composed of 24 dipole and 18 quadrupole magnets. A maximum field higher than 1.9 T is attained for the dipole magnets. From the field measurements with a precision better than +- 5 x 10-5, the sextupole component of the dipole magnets is less than 0.45 m-2 below 1.8 T. All the magnets have been already aligned to their precise positions taking the field properties into account from beam dynamical point of view. An RF cavity of ferrite-loaded two quarter wavelength coaxial type with bias windings of 4-turns has attained a tunable range about 15 times. An electron beam cooling system with a high voltage of 120 kV is designed to be applied to the beams lower than 200 MeVμ. Field properties of the guiding magnetic field of electron has been studied and a good quality field has been realized