Abstract: The proposed accelerator comprises a magnetic system (2), having an external magnetic pole (10) and an internal magnetic pole (9) which are interconnected by a magnetic circuit (8), an outer magnetic screen (13), an inner magnetic screen (12), a central magnetizing coil (5) and external magnetizing coils (7). Besides, the accelerator has a discharge chamber (3) comprising a concave anode (18) encompassing magnetic force surfaces (25) of a ionization zone (22), a sectional gas distributor (26), an inner side wall (15) and an outer side wall (16), the internal surfaces (20) whereof in the ionization zone (22) are located at an angle to a longitudinal axis (A--A) of the accelerator.