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 configura tion. 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 includin g the electrostatic and magnetic fields with dipole, quadrupole, and rotati onal symmetry. The new original construction of the electrostatic quadruple t has been manufactured. The sensitivity of this quadruplet to some misalig nments of the construction is investigated. (C) 2000 American Institute of Physics. [S0034-6748(00)01404-0].