A new possibility of continuation of few-nucleon dynamics studies at medium energies has appeared together with a new facility at the Institute of Nuclear Physics PAN in Kraków — The Bronowice Cyclotron Center (CCB). The new cyclotron PROTEUS provides a proton beam in an energy range of 70–230 MeV. Current progress in the theoretical calculations for four-nucleon (4N) systems is a main motivation to investigate p−^{3}He scattering. Due to the fact that the beam cannot be polarized, the only possibility to study spin observables is to build a polarized ^{3}He target system. A planned experiment assumes the construction of a cylindrical double Pyrex cell with separated pumping and target chambers with an additional polyamide film covering apertures for the passing beam and the reaction products. To polarize ^{3}He gas, the spin-exchange optical pumping method will be used.