Effect Of Laser Parameters On Momentum Coupling Coefficient Of Laser Propulsion

Laser propulsion was proposed by Dr. Arthur Kantrowitz for the first time in 1972. As a novel propulsion technology, it can be applied in many fields, such as micro-satellite launch, satellite orbit control and space debris removal. Air-breathing mode pulse laser propulsion is one of important propulsion methods. Numerous investigations have been done on it. This paper focuses on the study of effect of laser parameters on momentum coupling coefficient for the air-breathing mode laser propulsion.A parabolic light-craft was designed for the study. The flying condition of the craft under focusing beam was analyzed through numerical calculation. Three kinds of laser beam, Flat beam, Gauss beam were focused separately. The ignition curve could be confined through simulating three dimensions distribution of laser energy flux on focal plane. And the characteristic of three dimension focusing of reflecting beam was simulated when the incident solid beam and annular beam deviated from the principal axis of the light-craft.To explore the relation between wavelength and the threshold of air breakdown, between wavelength and momentum coupling coefficient, we chose 4 strong spectral lines 10P(20), 10R(12), 9P(28) and 9R(14) from 00⁰1～10⁰0 band and 00⁰1～02⁰0 band of tunable TEA CO₂ laser. Experiments show that the threshold decreases with the increase of laser wavelength and momentum-coupling coefficient keep unchanged when the wavelength variesA 100J TEA CO₂ laser was employed to study the effect of variety of pulse energy from 13J to 80J on the momentum-coupling coefficient. The results indicate that there is no obvious change in the momentum- coupling coefficient (C_m) when the pulse energy decreas from 80J to 24J. But C_m declines 52% when the energy is lower...