Accession Number:

ADA455896

Title:

Efficient Laser Ablation - Project AOARD 044033

Descriptive Note:

Final technical rept. 30 Aug 2004-20 Jul 2006

Corporate Author:

OSAKA UNIV (JAPAN) INST OF LASER TECHNOLOGY

Personal Author(s):

• Uchida, Shigeaki

Report Date:

2006-07-20

Pagination or Media Count:

31.0

Abstract:

This projects deals with problems of applying phenomena of laser-matter interaction to generating propulsive force in space. The advantages of using laser is that it can avoid use of explosive or toxic oxidizing chemicals and eliminate the necessity of high voltage power supply that is for electrical propulsion systems. The present report proposes a scheme of using liquid propellant. CO2 laser has been chosen as a laser source, since its wavelength is well absorbed by many kinds of liquid especially with O-H bonding. Pulsed format of temporal profile of laser radiation has been also chosen for the purpose. Repetitive Q-switched pulses were used in the experiments to achieve significant propellant heating with moderate amount of average laser power. It can be concluded that use of porous plate for feeding liquid propellant is possible. Several operating and designing parameters such as porosity, feeding pressure, propellant viscosity and vapor pressure, laser pulse repetition rate have to be optimized for the best performance of the system. Matching of the laser wavelength and absorption coefficient of propellant is also an important factor. It was found that realistic choice of these parameters is possible within reasonable range of physical value.

Descriptors:

• *PULSED LASERS
• *LIQUID PROPELLANTS
• *INFRARED PHENOMENA
• *SPACE PROPULSION
• Q SWITCHING
• ELECTRONICS
• ABLATION
• CARBON DIOXIDE
• VISCOSITY
• ABSORPTION COEFFICIENTS
• VAPOR PRESSURE
• PROPULSION SYSTEMS
• POROSITY
• OPTIMIZATION
• REPETITION RATE

Subject Categories:

• Lasers and Masers
• Electricity and Magnetism
• Unmanned Spacecraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE