Tribo Flow Separations, LLC proposes a novel method for measuring nitrogen ground state densities and rotational temperatures of molecular nitrogen in the free stream of arcjet ground testing facilities through emission spectroscopy measurements. Knowlede of these quantities will reduce uncertainties in the knowledge of local specific enthalpy which, in turn, is the defining quantity for the determination of heat flux to a surface of a probe or sample. In comparison with current methods, like Two Photon Laser Absorption Fluorescence, the proposed approach is cheaper than currently-used approaches by orders of magnitude, far easier to conduct and can be accomplished without interfering with other goals of testing; this aspect is of particular importance since no additional testing is required which saves testing costs. This new, unique method can be run as a standard diagnostic method without disrupting regular test schedules. It therefore provides the opportunity of monitoring test conditions very efficiently without relying on the stability of predefined test conditions, which in the end increases the reliability of the whole test campaign. Within Phase I, a single-channel, miniaturized spectrometer will be developed, constructed and used for its capability to measure nitrogen atom ground state densities and nitrogen molecule rotational temperatures. The foundational design of a multi-channel version will also be developed and then built, installed and tested at a NASA facility in Phase II.
A Phase II-developed instrument will be used in NASA arcjet facilities at NASA Ames. It reduces uncertainties in local specific enthalpy and determines nitrogen ground state densities; it won‘t alter regular testing schedules or protocols like other currently-applied diagnostic measurements. Its commercial aspect for NASA is that it offers rapid quantitative results to customers and provides quality control during measurement campaigns.
Two specific US site applications are the Arnold Engineering Development Complex plasma facilities and the Boeing Large Core Arc Tunnel. Commercial applications are those in which air plasmas are required, like in semi-conductor, plasma deposition and plasma surface treatment industries. Also, diagnostic testing services are to be offered that measure plasma densities and temperatures.