Laser Thermal Propulsion
Abstract
The objective of this research investigation is to determine, experimentally and analytically, the physical mechanisms that determine the behavior of continuous and quasi-continuous, laser sustained plasmas (LSP). The principal questions involve the effects of a forced convection environment, optical geometry and pulse format on the stability, fractional power absorption, plasma structure, and fluid mixing. The future application of this technology to space propulsion rests on the availability of lasers with powers in the megawatt range. It now appears likely that lasers of this size will be free electron lasers (FEL) that produce power as a series of pulses, rather than continuously. Transient argon plasmas were created using the 20 ns pulse from an excimer laser at a wavelength of 307 nm. These plasmas were self initiated from optical breakdown, requiring no auxiliary means for initiation as in the case for cw sustained plasmas. The decay of these plasmas were monitored using an optical multichannel analyzer (OMA), and it was found that the plasmas decayed with microsecond time scales. Keywords: Laser propulsion, Laser sustained plasmas, Plasma spectroscopy, Argon plasmas, Optical plasmotron, Free electron lasers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1988
- Accession Number
- ADA200558
Entities
People
- Dennis Keefer
Organizations
- University of Tennessee Space Institute