Ar I density profile and temperature determination by LIF measurement in a dusty plasma
Résumé
The PKE reactor devoted to dust particle studies presents in the plasma center a void of dust particles. The physical phenomena inside the void are of great interest for the physics of the dusty plasma. Thus, any information on the excitation level of the species in this region can improve the characterization of the void. For different plasma conditions, optical non intrusive diagnostics have been carried out. The spatial distribution of Ar neutral density is measured by Laser Induced Fluorescence. The transition from the (4s [3/2]) excited level is pumped at the known 667.9 nm wavelength. The laser is a Toptika 100 laser diode with a bandwidth of less than 1 MHz and an output power of 15 mW. The Argon fluorescence is observed at 750.5 nm through a wideband filter by an Hamamatsu photomultiplier. After locking acquisition, the signal is recorded by an analogical Sefram recorder. The temperature of the neutral is determined from the profile measurement. Further work will include argon ions characteristic.