Title :
Experimental study of CF4 conical theta pinch plasma expanding into vacuum
Author :
Pedrow, Patrick D. ; Nasiruddin, Abutaher M.
Author_Institution :
Dept. of Electr. & Comput. Eng., Washington State Univ., Pullman, WA, USA
fDate :
2/1/1989 12:00:00 AM
Abstract :
Langmuir probe, photodiode, and optical multichannel analyzer (OMA) measurements have been made on a pulsed CF4 conical theta-pinch plasma. A cloud of CF4 was puffed into a conical theta-pinch coil, converted to plasma, and propelled into the vacuum region ahead of the expanding gas cloud. At a position 67 cm away from the conical theta-pinch coil, the plasma arrived in separate packets that were about 20 μs in duration. The average drift velocity of these packets corresponded to an energy of about 3 eV. The OMA measurements showed that the second packet contained neutral atomic fluorine as well as charged particles. The electron temperature and ion density in the second packet were 2.0 eV and 1.5×1013 cm-3, respectively. The electron temperature and ion density in the wake plasma were 8.3 eV and 4×1011 cm-3 , respectively. This device can be used for plasma processing or as a laboratory test of numerical and analytical models of the expansion of plasma into vacuum
Keywords :
Langmuir probes; organic compounds; pinch effect; plasma density; plasma temperature; 2.0 eV; 20 mus; 3 eV; 67 cm; 8.3 eV; F; Langmuir probe; OMA measurements; analyzer; charged particles; conical theta pinch plasma; drift velocity; electron temperature; expanding gas cloud; ion density; measurements; neutral atomic fluorine; optical multichannel; photodiode; plasma processing; vacuum region; wake plasma; Atomic measurements; Clouds; Coils; Electrons; Plasma density; Plasma devices; Plasma materials processing; Plasma measurements; Plasma temperature; Pulse measurements;
Journal_Title :
Plasma Science, IEEE Transactions on
