Abstract <p>In the paper, the results of an experimental study of the integral characteristics of a laboratory model of a radio-frequency ion thruster with a beam diameter of 80 mm and krypton as the propellant are presented. The obtained characteristics are compared with the results of tests of the laboratory model using xenon as the propellant. The impact on the service life of the accelerating grid of the ion-extraction system of the thruster and the efficiency of ion-beam focusing of the use of krypton instead of xenon, which is most often used, is estimated. Surface erosion of the accelerating grid under the effect of xenon and krypton ions incident on the grid during operation taking into account the operating modes of the laboratory model of the radio-frequency ion thruster considered during the experiments is modeled. Based on the performed studies, it is possible to estimate the change in the integral characteristics of the radio-frequency ion thruster in the case of using a cheaper propellant compared to xenon. The obtained results can be applied to optimize the existing models of radio-frequency ion thrusters in order to achieve the highest efficiency of their operation using krypton.</p>