Ponomarov A. Beam formation in nuclear microprobe with allowance for an inhomogeneity of particle phase density

It was found in the thesis that a nonlinear transformation of particles phase coordinates in a microprobe probe-forming system is sensitive to the size of the initial distribution dispersion of particle phase density of an ion beam rather than its type. Taking this into account, the optimization of probe-forming process with allowance for an inhomogeneous phase density was carried out. The optimization task is based on the obtaining of a minimal contour size at half-maximum (FWHM) of particle density distribution on the target with respect to a fixed ratio of current in this contour to the total beam current. The real parameters of the phase density distribution of the ion beam in the object collimator plane were used in the optimization. These parameters were deconvolved from the beam brightness distribution measurements at the entrance to the nuclear microprobe channel of Institute of Applied Physics, NAS of Ukraine by means of a new original method. A new approach for matching of the obtained distribution parameters of the particles phase density with ion-optical characteristics of the probe-forming system was also proposed. In view of the foregoing a number of microprobe applied tasks were considered.