Micro-glow discharge

Table 4-12. Parameters of a DC Atmospherie-Pressure Micro-Glow Discharge in Air at...

Neutron Activation Analysis X-Ray Fluorescence Particle-Induced X-Ray Emission Particle-Induced Nuclear Reaction Analysis Rutherford Backscattering Spectrometry Spark Source Mass Spectrometry Glow Discharge Mass Spectrometry Electron Microprobe Analysis Laser Microprobe Analysis Secondary Ion Mass Analysis Micro-PIXE... 

D. Hill, T. Jawhari, J.G. Cespedes, J.A. Garcia and E. Bertran, In-situ monitoring of laser annealing by micro-Raman spectroscopy for hydrogenated silicon nanoparticles produced in radio frequency glow discharge, Phys. Status SolidiA, 203, 1296-1300 (2006). 

Stimulated (laser) excimer emission can be generated in pulsed high-pressure glow discharges. Dielectric barrier (silent) discharges or micro-wave discharges can be used to produce quasi-stationary or continuous incoherent excimer radiation. 

Jenkins, G., Manz, A., Optical emission detection of liquid analytes using a micro-machined d.c. glow-discharge device at atmospheric pressure. Micro Total Analysis Systems, Proceedings 5th p714S Symposium, Monterey, CA, Oct. 21-25,2001, 349-350. 

For analysis of solutions, ICP-mass spectrometry (ICP-MS) is very promising (Houk et al., 1980 Houk, 1986 Bacon et al., 1990). Recent advances in separation and preconcentration techniques are discussed by Horvath et al. (1991). Bacon et al. (1990) report that although ICP-MS is a multi-element technique, recent papers tend to concentrate on a small number of target elements. With isotope dilution mass spectrometry (IDMS), detection limits are further reduced (Heumann, 1988) IDMS is also suitable for accurate speciation in very low concentration levels of elements (Heumann, 1990). For the direct analysis of solid samples, glow discharge mass spectrometry (GD-MS) (Harrison etal., 1986) is of interest. Tolg (1988) has suggested that a substantial improvement in the absolute detection power of GD-MS, as applied to micro analysis, can be expected, at least in comparison with the ICP as ion source. 

Glow discharges have also now been miniaturized. In the discharge in a micro-structured system, described by Eijkel et al. [607], molecular emission is obtained and the system can be used successfully to detect down to 10 14 g/s methane with a linear response over two decades. A barrier-layer discharge for use in diode laser atomic spectrometry has also been described recently (Fig. 122) [608],... 

Saito M., Hirose F. and Okochi H. (1995) Comparative study of the determination of micro-amounts of boron in high-purity molybdenum by a spectrophotometric method using curcumin, spark source mass spectrometry and glow discharge mass spectrometry, Anal Sci 11 695-697. 

Preferred methods in trace determination of the elements include atomic absorption spectrometry (AAS), optical emission spectrometry (OES) with any of a wide variety of excitation sources [e.g., sparks, arcs, high-frequency or microwave plasmas (inductively coupled plasma, ICP microwave induced plasma, MIP capacitively coupled micro-wave plasma, CMP), glow discharges (GD). hollow cathodes, or laser vaporization (laser ablation)], as well as mass spectrometry (again in combination with the various excitation sources listed), together with several types of X-ray fluorescence (XRF) analysis [51]. 

Like corona and gas corona, plasma is the electrical ionization of a gas. However, the plasma (glow) discharge creates a smooth, undifferentiated cloud of ionized gas with no visible micro-discharges or macro-filaments. Also unlike corona or gas corona, plasma is created at much lower voltage levels. 

It must be reiterated that an atmospheric plasma glow discharge provides a treatment with high uniformity and homogeneity, along with the ability to micro-etch and functionalize the surface of films (in this case with carbon-based functionality). In the case of OPP film, the level of heat seal strength is 20% higher than the level obtained with corona pretreatment. 

Fig. 9.3.6 Photo of a micro-discharge device (MDD) in operation with visible glow emission, compliments of Caviton, Inc. [9], and envisioned MDD assembly with spectrometer (right-hand side).

Ghcrardi, N. Gouda, G. Gat. E. Ricard, A. and Massines, F. Transition from glow silent discharge to micro-discharges in nitrogen gas Plasma Sources Sci. Technoi, 2000. 9, 340-346... 

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