2D laser-collision induced fluorescence in low-pressure argon discharges

Development and application of laser-collision induced fluorescence (LCIF) diagnostic technique is presented for the use of interrogating argon plasma discharges. Key atomic states of argon utilized for the LCIF method are identified. A simplified two-state collisional radiative model is then used to establish scaling relations between the LCIF, electron density, and reduced electric fields (E/N). The procedure used to generate, detect and calibrate the LCIF in controlled plasma environments is discussed in detail. LCIF emanating from an argon discharge is then presented for electron densities spanning 10(9) e cm(-3) to 10(12) e cm(-3) and reduced electric fields spanning 0.1 Td to 40 Td. Finally, application of the LCIF technique for measuring the spatial distribution of both electron densities and reduced electric field is demonstrated.