Experimental measurements of the dynamic electric field topology associated with magnetized RF sheaths

• Published in: 2011 Abstracts IEEE International Conference on Plasma Science p. 1
• Main Authors: Martin, E. H., Caughman, J. B. O., Isler, R. C., Klepper, C. C., Shannon, S. C.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.06.2011
• Subjects: Heating; Radio frequency
• ISBN: 1612843301; 9781612843308
• ISSN: 0730-9244
• DOI: 10.1109/PLASMA.2011.5992921

Summary form only given. Non-perturbative diagnostics capable of measuring time varying sheath properties lend tremendous insight into plasma antenna interactions for a wide range of systems from RF heating in Tokamaks to RF sheath enhancement of industrial plasma processes. In this presentation, results from an experiment designed to optically study the dynamic electric field topology of a magnetized RF sheath with a planar geometry are presented. The experiment consists of an electrode biased at 13.56 MHz immersed in a high density plasma generated from an ECR source operated at 2.45 GHz. An optical assembly surrounding the RF biased electrode was designed to solely collect emission originating from the magnetized RF sheath thus eliminating unperturbed emission. Utilizing the dynamic Stark effect to model the optical emission of species in a time varying electric field and a novel line shape analysis package the sheath parameters can be determined from the time-averaged and phase resolved optical emission spectra. The electric field parameters determined from the emission spectra are compared to an independent model of a magnetized RF sheath similar to the unified sheath model of Riley[Riley, M.E., 1995; Riley, M.E., 1996]. Working gases of hydrogen and helium are considered.