First high-resolving mass analyzers were built ≈80 years ago as sector field systems, well reproducible ones, however, only much later. Besides these sector-field systems there are three other types of mass analyzers: (1) Penning trap mass analyzers, have achieved the highest resolving powers, but require big technological efforts. (2) Time-of-flight mass analyzers have become the most versatile systems, while high performing multi-reflection time-of-flight systems have only started to be used. (3) Fourier Transform and Orbitrap mass analyzers have achieved spectacularly high mass resolving powers, but are also technically demanding and difficult to build systems.

The high accuracy that can be achieved by the Boundary Element Method when it is used to solve the Laplace and Poisson equations for electrostatic systems is discussed. Applications to charged particle optics are described, with the emphasis on the commercial CPO programs [1]. The BEM is a charge-based method and so is ideally suitable for systems that include space-charge and/or cathodes. It can deal easily with electrodes of very different sizes. These and other properties of the BEM are illustrated by a range of benchmark tests.

A wave optical calculation of the probe size of a low energy scanning electron microscope is presented. The resolution for the optimal aperture was computed and compared with results of standard approaches. The effect of deflection aberrations is also considered, and it was found to be critical for the landing energies below 5eV and fields of view larger than 100 x 100 μm2.

Two techniques for use with SIMION [1] are presented, boundary matching and genetic optimization. The first allows systems which were previously difficult or impossible to simulate in SIMION to be simulated with great accuracy. The second allows any system to be rapidly and robustly optimized using a parallelized genetic algorithm. Each method will be described along with examples of real world applications.