Optimization programs are becoming available to support the designing of complicated lens systems in charged particle optics. By exploring the consequences of design decisions automatically, they can increase the effectiveness of the designer. This increases the quality of the resulting design, or makes it possible to design systems that are too complicated to develop by hand. A typical problem is that these optimization programs often only produce an optimized design for one mode of operation of the system, whereas the optical system has to function for a range of modes. For a designer these multi mode design constraints often are difficult to handle. In this paper we report how a single mode optimization program is used for designing an actual multi mode transport lens system. The final design, which is too difficult to develop in a conventional way, is presented. The optimization program used is based on the Second Order Electrode Method (SOEM). Because SOEM uses a very simple model to calculate the electrostatic field, the properties of the final design are checked with a more accurate simulation program. The optical properties calculated by SOEM are accurate enough to form a basis for design decisions.

Date Published: 3 September 1993
PDF: 12 pages
Proc. SPIE 2014, Charged-Particle Optics, (3 September 1993); doi: 10.1117/12.155701

Published in SPIE Proceedings Vol. 2014:
Charged-Particle Optics
William B. Thompson; Mitsugu Sato; Albert V. Crewe, Editor(s)