Monday, May 21, 2007, 11am - 12pm, MDEA

The Structure of Colloid Thruster Beams

Manuel Gamero-Castaño

Jet Propulsion Laboratory

Abstract

A Colloid thruster is an electrostatic accelerator of charged droplets generated by an electrospray.  The low thrust and high thrust stability associated with a single emitter are ideal for precision spacecraft positioning applications.  This technology will be tested in the Disturbance Reduction System-Space Technology 7 mission (NASA-JPL), which is a precursor of the ambitious Laser Interferometer Space Antenna mission (NASA-ESA). Although the colloid thruster engine for DRS/ST7 is at an advanced stage of development and key performance parameters have been demonstrated, the structure of the electrospray beam is largely unknown.  A good knowledge of the beam is necessary to optimally design the thruster´s accelerating electrodes, and to assess its interaction with spacecraft surfaces. This research seminar will introduce two novel detectors (an induction charge detector and a retarding potential analyzer) used for the study of colloid thruster beams, a detailed experimental characterization of these electrosprays, and analytical and numerical solutions of a beam model that captures the salient features, including the spreading of the beam caused by its own space charge.
 

Biographical sketch

Manuel Gamero-Castaño received his B.S. in Chemical Engineering at Escuela Superior de Ingenieros (Universidad de Sevilla, Spain,1995), and his Ph.D. in Mechanical Engineering at Yale University (New Haven, CT. 1999).  His Ph.D thesis was awarded the S. K. Friedlander Award from the American Association for Aerosol Research in 2001. M. Gamero-Castaño joined Busek Co Inc (Natick, MA) in 1999 where he developed and directed Busek's colloid thruster program. This research program led to Busek's acquisition of a contract for developing and delivering the colloid thrusters for the JPL's DRS-ST7 mission.  M. Gamero-Castaño joined the Jet Propulsion Laboratory in 2004, where he currently works as a Senior Engineer in projects aimed at developing colloid thruster technology for the DRS-ST7 and LISA missions. Other areas of interest of Dr. Gamero's reasearch include the numerical modeling of the plasma discharge and wall erosion of Hall thrusters, the development of aerosol diagnostic techniques, and the study of a variety of phenomena associated with the electrospraying of liquids.