1. APPLICATION OF DIAGNOSTICS TO CHALLENGING DISCHARGE ENVIRONMENTS
We have hosted collaborators to utilize laser-collision induced fluorescence (LCIF) diagnostics developed through PSC support.
Neil Arthur (John Foster): Biased cusps for plasma flow modification.
Amanda Lietz (Mark Kushner): Atmospheric pressure plasma jets in humid environments.
LCIF Diagnostic
Multi-cusp plasma
Plasma jets
2.3% H2O shroud
Pure He
ne (Peak: ~ 1013 e/cm3)
LIF
Measured
electron densities
 Collaborative interactions leverage unique capabilities to address challenges.
DOE Plasma Science Center
Control of Plasma Kinetics
HIGHLIGHT
June 2018 1

2. GAS TEMPERATURES AND ELECTRON DENSITIES IN 13 MHz Ar AND He ATMOSPHERIC PRESSURE PLASMA JETS (APPJs)
Ar or He flow through a quartz tube with a 13 MHz powered needle electrode, grounded outer ring electrode (Bruggeman design).
Tgas measured by fitting a model to N2 (CB) emission from background air (top figure).
ne measured by Stark broadening of H emission from trace added H2.
Measurements along jet axis as a function of distance from the nozzle, bounded by a substrate or no substrate.
Tg is higher for He than for Ar, and nearly independent of distance (bottom figure).
ne, cm-3(not shown) = 1-5x1013 (Ar); 5x1012 (He).
Figure: (top) N2 (CB) optical emission bands (solid points) in Ar and He APPJs, and model fits with adjustable parameter Trot(C) = Tg; (bottom) Tgas vs distance from nozzle with quartz substrate present (Ar, He), or not present (He).
DOE Plasma Science Center
Control of Plasma Kinetics
HIGHLIGHT
June 2018 2