Effect of Flow Velocity on Generation Conditions of Argon LSP using Diode Laser

Laser propulsion is a novel space transportation system that obtains thrust through the laser sustained plasma (LSP) generated by the focused laser beam. This system is expected to have a higher specific impulse than arcjet system and long lifetime because of no electrode erosion. Considering the adaption of LSP to the space transportation system, it is necessary to generate LSP using a diode laser which has high energy conversion efficiency. In previous studies, we have successfully generated diode laser sustained plasma under conditions of argon gas inclusion. However, in consideration of the application to laser propulsion, it is necessary to investigate the generation condition of LSP and various characteristics under flow velocity conditions. In this study, we investigated changes in the generation conditions depending on the flow velocity.