Laser Induced Fluorescence
Laser-induced fluorescence (LIF) is a non-instrusive optical measurement technique that allows for measurents of the velocity distribution functions (VDF)of atom and ion species along the laser beam direction by measuring the Doppler shift. The main goal using LIF is to demonstrate the possibility of using a single tunable diode laser to excite Xenon neutrals and ions and measure LIF signal. Experiments are carried out at the Small Hall thruster Facility using the 2.6cm miniaturized cylindrical Hall thruster with a 200 W power level.
Two electron transitions are used in these experiments. The Xe ions are excited from a well-known metastable level 5d2F7/2 to 6pD05/2 by 834.953 nm wavelength with de-excitation at 542.066 nm. The Xe atoms are excited by 834.91157 nm from 6s[1/2]02 with de-excitation at 473.5460 nm.