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The NICA collider can operate with polarized light ions in two modes. At the Preferred Spin mode (PS mode) the periodic spin motion along the closed orbit is unique, i.e. the static magnetic lattice determines a single stable orientation of the beam polarization at any collider’'s place. At the Spin Transparency mode (ST mode) any spin direction repeats every particle turn along the closed orbit, i.e. the collider’s magnetic lattice is transparent to the spin. ST mode allows one to use a completely new approach to carry out experiments with polarized ions at high precision level. The features of ion polarization control in the ST mode are discussed. The schemes of polarization control in the NICA collider in the ST mode are presented.

The toroidal low-energy particle accumulator is intended for confining and electronic cooling of a circulating positron beam and generating antihydrogen and positronium in flight. Its special features are a longitudinal magnetic field, a spiral particle winding, and a sectional structure of the optical components, which serve to form a closed orbit. The longitudinal magnetic field simultaneously magnetizes the positron beam and, as a consequence, ensures a long lifetime for the circulating beam. However, such a field results in strong coupling of the horizontal and vertical degrees of freedom and the appearance of additional resonances. The particle dynamics is simulated using the specially developed BETATRON computer code, based on the BOLIDE program package (for producing interfaces for computational and simulation programs). In the present work, the results of the simulation of particle dynamics and a calculation of the structure functions for a positron storage ring are presented.

The scheme of an internal injection of Au atoms into the working space of the "Krion-2" electron string ion source (ESIS) was applied and tested. In this scheme Au atoms are evaporated from the thin tungsten wire surface in vicinity of the source electron string. Ion beams with charge states up to Au51+ were produced. Ion-ion cooling with use of C and O coolant ions was studied. It allowed increasing of the Au51+ ion yield by a factor of 2. Ions of Kr up to charge state 28+ were also produced in the source. Electron strings were first formed with injection electron energy up to 6 keV. Methods to increase the ESIS ion output are discussed.

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