Theoretical study of short electrostatic lens for the Columbia ion microprobe

A short probe-forming system is developed for the Columbia Microprobe that includes four electrostatic quadrupoles with a Russian quadruplet configuration. The smallest beam spot size and appropriate optimal parameters of the probe-forming systems have been found. These parameters of the system are compared with appropriate parameters of other field configurations including the electrostatic and magnetic fields with dipole, quadrupole, and rotational symmetry. The new original construction of the electrostatic quadruplet has been manufactured. The sensitivity of this quadruplet to some misalignments of the construction is investigated. (C) 2000 American Institute of Physics. [S0034-6748(00)01404-0].