Laser Spectoscopy of Plasmas.
Annual rept. Dec 86-Dec 87,
CALIFORNIA UNIV BERKELEY DEPT OF MECHANICAL ENGINEERING
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During the past year, work was continued developing novel advanced laser spectroscopy plasma diagnostic methods. The methods are based on observing the doppler shift in the absorption lines of ionic species. Two methods under study are Velocity Modulated Laser Spectroscopy and Two-Beam Doppler Shift Laser Spectroscopy. The scientific goal of the work is to increase understanding of plasmas by making in-situ measurements of ion drift velocities, concentrations and temperatures in a non-intrusive fashion. The scientific approach is to combine conventional laser spectroscopies with velocity detection. Using a method such as Rayleigh, fluorescence, or Raman scattering, one probes the Doppler profile of the specie of interest, observing shifts in the Doppler profile that arises because of the presence of a electric field. The shift may be related to the ion mobility, and thus conductivity, if the electric field is known, or to the electric field if the mobility is known. Temperature and concentration may be recovered by the conventional means. Keywords Plasmas, Electric propulsion.
- Physical Chemistry