Optimization of the quadrupole probe-forming system with individual power supplies for lenses

This study reviews a quadruplet of magnetic quadrupole lenses, where each lens is fed from an individual power supply. In this case the power supplies of two last lenses (along the course of the beam) are selected from the condition of ensuring the stigmatic focusing, while the power supply values of two first lenses are free parameters. These parameters form a two-parameter set, where the functional characterizing the acceptance of a probe-forming system is determined. It has been shown that the use of four individual power supplies for lenses in the quadruplet allows us to make the acceptance more than two times larger.