• Journal of Surface Science and Engineering
• /
• v.34 no.5
• /
• pp.384-390
• /
• 2001

The hollow cathode discharge is a kind of plasma formation scheme in which plasma is formed inside a hollow structure, the cathode, with current to a nearby anode of arbitrary shape. In this scheme, electrons reflex radially within the hollow cathode, establishing an efficient ionization mechanism for gas within the cavity. An existence condition for the hollow cathode effect is that the electron mean-free-path for ionization is of the order of the cavity radius. Thus the size of this kind of plasma source must decrease as the gas pressure is increased. In fact, the hollow cathode effect can occur even at atmospheric pressure for cathode diameters of order 10-100 $\mu\textrm{m}$. That is, the "natural" operating pressure regime for a "micro hollow cathode discharge" is atmospheric pressure. This kind of plasma source has been the subject of increasing research activity in recent years. A number of geometric variants have been explored, and operational requirements and typical plasma parameters have been determined. Large arrays of individual tiny sources can be used to form large-area, atmospheric-pressure plasma sources. The simplicity of the method and the capability of operation without the need for the usual vacuum system and its associated limitations, provide a highly attractive option for new approaches to many different kinds of plasma applications, including plasma surface modification technologies. Here we review the background work that has been carried out in this new research field.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2005.05a
• /
• pp.45-47
• /
• 2005

The Dielectric Barrier micro-hollow cathode structure and it's upper pD limitation are investigated for determining of optimum hollow cathode discharge condition. In experiment, discharge is sustained by AC diriving and investigated gas is pure Xe. From Experiment, Optimum pD range is lower than 0.72 torr.cm at pure Xe and Cu cathode.

• Journal of the Korean Vacuum Society
• /
• v.12 no.1
• /
• pp.51-54
• /
• 2003

The spontaneous oscillations in the optogalvanic signals are observed in negative glow region of Ar hollow cathode discharge. The spontaneous oscillations in the optogalvanic signals are observed at low discharge currents less than about 3 mA. Based on the simultaneous measurements of both the density variation of metastable atoms and emission intensities of the 1s-2p transitions, one of the possible mechanisms for the spontaneous oscillation is considered to be related to the stepwise ionization of the metastable atoms due to collisions with slow electrons in the discharge.

• Journal of the Korean Chemical Society
• /
• v.42 no.3
• /
• pp.323-327
• /
• 1998

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.488-491
• /
• 2002

We report the observation of line shapes in the optogalvanic spectrum, which are different from those of absorption, for transitions origination from the $3P_2$ ($1s_5$ in Paschen notation) metastable level of argon. The OG line shapes resemble those of absorption and be used to diagnose the characteristics of the discharge plasma. The measured plasma temperatures of Ar hollow cathode discharge for several metal cathodes are about 620~780K at discharge current of 7~10mA.

• Journal of the Korean Chemical Society
• /
• v.39 no.5
• /
• pp.399-407
• /
• 1995

Electrothermal-Hollow Cathode Glow Discharge Spectrometry (Et-HCGDS) has been constructed in our laboratory for in-situ monitoring of traceble amounts of rare earth elements and actinides. Et-HCGDS is the portable glow discharge system that can perform the trace analysis of elements. The main structural design of Et-HCGDS was based upon the electrothermal heating and glow discharge techniques. More details on Et-HCGDS are available elsewhere. In this study, air was used as a flow gas for the glow discharge system. As a result, the emission spectra of air were collected and the assignment of air emission lines was performed with helps of pure nitrogen and oxygen emission spectra and previously published results. We found that the emission lines of air plasma were mainly due to nitrogen molecules. This paper includes the complete assignments of the air emission lines observed by using Et-HCGDS. Also, this study will be an useful reference for spectrochemical anaysis including air analysis.

• Analytical Science and Technology
• /
• v.11 no.3
• /
• pp.167-173
• /
• 1998

An electrothermal vaporization-hollow cathode glow discharge-atomic emission spectrometer(ETV-HCGD-AES) has been developed for detecting heavy metals in human serum and urine samples. Fisrt of all, we designed a glow discharge cell for atomic emission spectrometry and its analytical performance was studied with the standard reference materials(SRMs) purchased from the NIST. Practically, the ETV-HCGD-AES demonstrated better instrumental sensitivity and selectivity for detecting Hg and Pb in the SRMs, serum and urine, than ICP-OES since the ETV-HCGD-AES was not required the complicate sample digestion procedure, which improved sample transportation efficiency.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.18 no.9
• /
• pp.870-875
• /
• 2005

We measured the optogalvanic signal and discharge voltage-current(V-I) curve under the two different discharge conditions with different buffer gases, Ar, and Ne. When the Gd was used as a cathode material at low discharge current less than 10mA, a significant change was observed in the current-voltage curve. Time resolved optogalvanic signal measurement were measured by the diode laser of which wavelengths correspond to metastable transition line of these gases (Ar, Ne). From these measurements, we found that the characteristics of the V-I curve strongly depend on the Penning ionization process.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.41 no.8
• /
• pp.875-882
• /
• 1992

Titanium carbide(TiC) films, known as having excellent characteristics of resistance to wear and corrosion, were deposited on SUS-304 sheets using HCD(Hollow Cathode Discharge) reactive ion plating with acetylene gas as the reactant gas. The characteristics of TiC films were examined by X-ray diffraction, micro-Vickers hardness tester, ${\alpha}$-step, SEM(Scanning Electron Spectroscopy), ESCA(Electron Spectroscopy for Chemical Analysis), and AES(Auger Electron Spectroscopy) and the results were discussed with regard to the changes of various deposition conditions(bias voltage, acetylene flow rate, temperature).

• Proceedings of the KIEE Conference
• /
• 2007.11a
• /
• pp.192-193
• /
• 2007

A hollow cathode which has extremely stable discharge characteristic has been developed. This is composed of the two separated lanthanum hexaboride ($LaB_6$) of a disk type in the tube as the electron emitters. The way of design is of great advantage to extend the surface discharge area of the $LaB_6$, which is also useful for optimal fixing of the $LaB_6$. The hollow cathode is capable of producing 30 kW (100 V, 300 A) of power continuously.