New experimental and theoretical data on charge exchange (CE) cross sections are presented for low-energy collisions (10-500 eV u −1 ) of W + and W 2+ ions with H, H 2 and He atoms. The CE cross sections are calculated using the ARSENY code based on the hidden crossing method. The isotope effect (mass dependence) in collisions of W + and W 2+ ions with hydrogen isotopes H, D, T is studied in the framework of the adiabatic theory of transitions in slow collisions. Furthermore, the electron loss (EL) and CE cross sections for the energy range of 1-10 5 keV u −1 are calculated for tungsten and its ions W q+ (q = 0-40) colliding with H, He, N, Ar and W atoms using the computer codes (CAPTURE, DEPOSIT and RICODE) based upon the Born approximation and the classical energy-deposition model. The data obtained can be used for plasma modelling, planning and interpretation of future experiments in fusion devices using tungsten as a material for the plasma-facing components.