Colloid Thrusters, Physics, Fabrication and Performance

Abstract

'ublic reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing in. tata needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other . SUPPLEMENTARY NOTES ABSTRACTThis document summarizes the results of 3 and 1/2 years of work by our team on the basic physics and technology required for the development of Colloid Thrusters (also called more recently Electrospray Thrusters). The research covered the basic physics of operation in the mixed ion-droplet mode, later extended to the newly discovered pure ionic mode, the microfabrication in Silicon of two types of arrays of colloid or electrospray emitters, and the development of a quantitative theory for the colloidal regime (no ions). This Executive Summary describes briefly the various achievements, with reference to our interim Reports and to our publications. Special emphasis is placed on the results that were obtained during the one-year extension (2004), which were not covered in our interim reports. The Theses, published papers and Conference papers for 2004 are enclosed in a companion CD disk; earlier Theses and publications were similarly attached to previous Reports. SUBJECT

Electric Micropropulsion

“…5) of a wide variety of options for high specific impulse micropropulsion gave us a strong indication of the potential of colloid thrusters, and opened up our research in this area. The principal motivations are associated with the intrinsically small unit thrust obtainable (of the order of 10 -7 N per colloid emitter), the possibility of several types of precise control, and the ability to cluster large numbers of identical emitters using MEMS techniques [6] The modeling work initiated by Khayms [5] was extended by P. Lozano, who also pioneered ion optics techniques for experimental Time-of-Flight work with these thrusters. This work is documented in Ref.…”