Initial Considerations of a Dust Dispenser for Injecting Tungsten Particles in Space
Memorandum rept. Nov 2013-Aug 2014
NAVAL RESEARCH LAB WASHINGTON DC SPACECRAFT ENGINEERING DEPT
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This document reviews exploratory work to design, build, and test a table-top sized tungsten particle dispenser. A small canister and dispenser system within a vacuum bell jar is described to provide qualitative and quantitative observations of the dispensed particle stream. We selected tungsten carbide spheres and irregular tungsten powders all under 100 microns, driven by previous work. That work investigated the benefits of identical spherical particles, approximately 30 microns, filling an orbiting ring about the Earth to enhance drag, causing small pieces of orbital debris to enter the atmosphere. Using only gas or a gas-driven piston to propel the particles, many tests showed that increasing pressure yielded increasing stream velocity and higher velocity in vacuum than in air. Speed goals could be achieved and controlled, but because the speed and mass flow rate were directly linked, an abrasive blaster design was used to first mix the particles with the gas before exiting a conical nozzle. The clumping of particles is unwanted as it changes ballistic properties and decay rate. Clumping was seen with irregular powders, and methods to mitigate this problem are discussed. A summary of trends from testing, designs, and topics for the future end this report.
- Physical Chemistry