Optimized deceleration characteristics of multicharged ion beams from electron cyclotron resonance ion source

At present it is necessary the satellite lifetime 10-15 years for operating in space. Xenon is used as fuel for ion engines of satellites. There are problems of accumulated damages at irradiation and sputtering by low energy Xe ion from the engine. It is required to construct database of sputtering yield of ion beams in the low energy region from a hundred eV to 1keV. We are trying to investigate experimentally sputtering yield on satellite component by irradiating the low energy Xeq+ ion beams. We use the electron cyclotron resonance ion source (ECRIS) in the irradiation experiments. We decelerate the beam energy to several hundred eV after extraction at high voltage 10kV. It is found we cannot neglect the contribution of the space potential of the plasma in the ECRIS of several tens eV. We measured the plasma parameters and ion beam deceleration characteristics in operating conditions on ECRIS. As the results, it was found in operating ECRIS condition of low charge state ion being dominant that the space potential of the ECRIS has an effect of 10 similar to 20% at the beam energy at about 100eV in conducting irradiation experiments on satellite component materials.