A novel technique to control r.f.-powered Grimm-style glow discharge plasmas is described. A new channel of d.c. current driven by the self-bias potential is opened by using a low-pass filter circuit and a load resistor; as the result, a large number of electrons can flow along the d.c. circuit channel including the plasma body from the grounded electrode to the sample electrode. This phenomenon is effective for improvement of the detection sensitivity in the optical emission spectrometry. Atomic emission lines having lower excitation energies are predominantly enhanced by a factor of 10-20. The conduction of the d.c. bias current could promote these excitations.
ASJC Scopus subject areas
- Analytical Chemistry
- Atomic and Molecular Physics, and Optics