Author(s)

R. Godard

Abstract

The theory of optimal design has proved its importance in many applications in engineering and applied mathematics. The redesign of old problems such as a capacitor in an ionized medium has motivated new studies and new plasma diagnostic devices. Here we present some examples of optimal design of electrodes in Electrostatics and Electromagnetism with applications in plasma physics. In our first example, we present a study of the interaction between a uniform plasma and a planar substrate. In order to increase the uniformity of etching and deposition processes, we suggest an optimal design for substrate-holders by using a guard-ring in the shape of a ‘doughnut’. The possible consequences on plasma processes are analyzed and discussed. We would also like to illustrate the techniques of optimal design in space science for modifying the design of electrodes for a planar plasma capacitor (a plasma capacitor is a device for measuring the electron density in the Ionosphere). This reduces edges effects. Other techniques of optimal design are presented, such as the measurement of the conductivity in the Stratosphere by Gerdien condensers. Finally, although our last example does not involve numerical simulations, the interaction plasma-object is of great importance in space science from telecommunications satellites to scientific instruments. A great danger for scientific instruments comes from the charging of insulators. Many devices are supported by a boom, which is often an insulator. We suggest different techniques for hiding an insulator. Keywords: optimal design, material science, space science, plasma physics.

Keywords

optimal design, material science, space science, plasma physics