The development of the method of high-intensity implantation of low-energy ions requires the design of an efficient system for generating high-intensity ion beams of various elements with a current density of tens and hundreds of milliamperes per square centimeter with ion energies not exceeding some kiloelectronvolt. This paper considers the regularities of formation of high-intensity beams of nitrogen ions and argon and mixed beams of argon and hydrogen ions in spherical and cylindrical grid systems with ballistic focusing of the ion beam. The studies were carried out with the plasma-immersion formation of repetitively pulsed ion beams with duration from units to hundreds of microseconds and a pulse frequency of up to 105 pulses/s with negative bias potentials in the range from 0.6 to 3 kV. The possibility of stable formation of gas ion beams with an ion current density of up to 0.7 A/cm2 is demonstrated.