SPATIAL RESOLUTION IMPROVEMENT OF THE NUCLEAR SCANNING MICROPROBE CHANNEL OF THE ANALYTICAL ACCELERATOR COMPLEX OF THE API NAS OF UKRAINE

Abstract

The probe-forming system of a nuclear scanning microprobe based on a quadruplet of magnetic quadrupole lenses with three independent power supplies has been studied. In the stigmatic focusing mode, the third power supply is a free parameter affecting the ion-optical properties of the microprobe. The optimal system was selected as a result of solving an optimization problem in which the figure of merit was the reduced collimated acceptance. The numerical simulation of the beam focusing process in that one-parametric system, taking into account the experimentally measured distribution of protons in the trajectory phase space, showed that the dimensions of the beam spot on the target can be reduced several times compared to the working system. At the same time, the current density in the focused spot increases by about one order.