Title :
Plasma generation in an organic molecular gas by an ultraviolet laser pulse
Author :
Zhang, Y.S. ; Scharer, J.E. ; Lam, N.T.
Author_Institution :
Dept. of Electr. & Comput. Eng., Wisconsin Univ., Madison, WI, USA
Abstract :
Summary form only given. Plasma generation in an organic molecular gas through a one-photon ionization process is studied. A 1-D model is derived to describe the photon flux flow and electron density evolution. Plasmas are generated in a low-ionization potential gas, tetrakis (dimethylamino) ethylene (TMAE) vapor, through a one-photon ionization process by an ultraviolet laser beam (E - 10 mJ, /spl tau/ - 17 ns) at 193 nm. A new method is used to measure the 193-nm ultraviolet (UV) photon absorption cross-section in TMAE. It is determined to be 1.1 /spl plusmn/ 0.3 /spl times/ 10/sup -7/ cm/sup 2/ from the axial profile of electron density. A high-density sharp boundary plasma sheet produced by a UV sheet beam obtained from the laser output through an optical system is examined. The microwave reflection from the plasma sheet is examined, and the potential application of a TMAE plasma as a mirror for microwave reflections is discussed. When TMAE is ionized in a higher-pressure background gas (argon/helium), a highly collisional, diffuse-boundary plasma can be produced.
Keywords :
plasma production by laser; 10 mJ; 17 ns; 193 nm; 1D model; Ar-He; TMAE vapor; UV sheet beam; axial profile; diffuse-boundary plasma; electron density; electron density evolution; high-density sharp boundary plasma sheet; higher-pressure background gas; laser output; low-ionization potential gas; microwave reflection; microwave reflections; one-photon ionization process; optical system; organic molecular gas; photon flux flow; plasma generation; tetrakis (dimethylamino) ethylene; ultraviolet laser pulse; Electrons; Gas lasers; Ionization; Laser beams; Laser modes; Optical reflection; Particle beams; Plasma applications; Plasma density; Plasma measurements;
Conference_Titel :
Plasma Science, 1993. IEEE Conference Record - Abstracts., 1993 IEEE International Conference on
Conference_Location :
Vancouver, BC, Canada
Print_ISBN :
0-7803-1360-7
DOI :
10.1109/PLASMA.1993.593401