A source of polarized deuterons and protons (SPI) has been created as part of the experimental program on accelerated polarized beams at the Nuclotron superconducting synchrotron. The electrostatic accelerating tube has been replaced by an accelerator with spatially homogeneous quadrupole focusing (RFQ linac), and the power-supply system of the ion sources has been also replaced to work with the source of polarized ions on the preinjector of the LU-20 linear accelerator. This article presents the results of 52–54 experiments on the acceleration of polarized protons and light ions in the Nuclotron.