Operation Characteristics of Laser Driven Plasma Wind Tunnel

A laser driven plasma wind tunnel using a 2 kW class continuous wave laser was developed as a high speed and high density atomic oxygen generator. Firstly, its operation conditions were examined. Using argon and oxygen as working gases, laser sustained plasma (LSP) was successfully produced in the plenum pressure range from 0.30 MPa to 0.95 MPa, and then the LSP was expanded to the vacuum chamber through the convergent-divergent nozzle. Next, plume characteristics were evaluated by Pitot probe and laser absorption spectroscopy using an absorption line of ArI 772.38 nm. As a result, the Mach number and the specific enthalpy around the center were 5.0 to 6.5 and 3.0 MJ/kg to 5.2 MJ/kg, respectively. The maximum flux density of atomic oxygen was estimated as 2.2×1021 cm-2s-1