Building a micrometer-scale electrostatic lens by hand

A technique is presented by which one can construct a micrometer-scale, two-electrode, electrostatic lens using readily available supplies and a relatively steady hand. The first-aperture diameter can range from several hundred ångströms to several micrometers, and the second aperture is 20 μm in diameter; the space between the electrodes is 8 μm. A method for extending the technique to lenses of three (or more) electrodes is described. Potential differences of over 500 V have been applied to the electrodes without breakdown. The capacity of the lenses to send an electron beam through crossover with relatively low distortion has been demonstrated. © 1993.