Department of Experimental Physics - Laboratory Of Corona And Surface Discharges Research

Laboratory Of Corona And Surface Discharges Research

Laboratory of corona and surface discharges research

Personel:
Head of laboratory:
    Prof. RNDr. Mirko Černák, PhD.
Members of laboratory:
    Assoc. prof. RNDr. Anna Zahoranová, PhD.
    RNDr. Jozef Ráheľ, PhD.
    MSc. Dušan Kováčik
    MSc. Andrej Buček

PhD. Students:
    MSc. Mária Odrášková

FUNDAMENTAL research in the team focuses on experimental study and computer simulations of the following types of electrical discharges, which are generating atmospheric-pressure “cold” plasmas:

Corona discharges: DC positive [1-4] and negative [5-9] corona discharges, pulsed positive corona discharges [2], pulsed surface corona discharges (Fig.1) [10-12].
Barrier discharges: volume barrier discharges, surface barrier discharges [13-17] (see Fig.2) and coplanar surface barrier discharges [18,19] (see Figs.3(a)-(b), and Fig.4)
Underwater electrical discharges: Pulsed positive underwater coronas [20], diaphragm discharge [21]

Since the treatment of a surface by atmospheric-pressure “cold” plasmas affects about 10 nanometers of the very surface layer, our APPLIED research concentrates on the applications of atmospheric-pressure “cold” plasmas to nano-technological problems, primarily in the polymer-processing [10,19,21], rubber [11,12], textile [13-16] (see Fig.5), car [14], and electronics industry [15].

Fundamental physical processes in the discharges are studied experimentally using sub-nanosecond measurements of the discharge electrical parameters, emission spectroscopy, and sub-nanosecond high-sensitivity optical measurements.

For the sub-nanosecond measurements of the discharge electrical parameters we are equipped by a set of HV and current probes, and fast digital oscilloscopes (i.e. Hewlett-Packard HP 54616B).

To study the atmospheric-pressure plasma geometry we are using a home-made CCD device (see Fig.6). Optical measurements of the discharge development with sub-manosecond time resoltion are made in collaboration with the International Laser Centre in Bratislava.

The spectroscopic measurements are realised in a close collaboration with the Dept. of Physical Electronics, Masaryk University, Brno and the Inst. of Plasma Physics, Prague.

The following power supplies are used to generate the above mentioned discharges and feed the plasma sources developed:

high-voltage (up to 100 kV) DC supplies
thyratron pulsed power supply (up to 30 kV)
pulsed HV (up to 60 kV) power supply with a rotating spark gap
RF HV power supplies with the power up to 1 kW

In the fields of fundamental study of the electrical discharge mechanism have a long-term collaboration with the following institutions:

Laboratoire de Génie Electrique, Université de Pau, France
Department of Physics,University of Greifswald, Germany
Department of Electrical and Computer Engineering, Plasma Sciences Laboratory, University of Tennessee, Knoxwille, USA
Dept. of Physical Electronics, Masaryk University, Brno, Czech Republic

In the field of plasma application we are collaborating with the following institutions:

TANDEC, Knoxwille, USA
Faculty of Electrical Engineering, Shizuoka University, Japan
MATADOR Co., Púchov. Slovak Republic
Research Inst. of Textile Chemistry, Žilina, Slovak Republic
REDA Tech, Bratislava, Slovak Republic
AHLSTROM Research Centre, Lyon, France
YKI, Stockholm, Sweden
Institute of Plasma Physics ASCR, Prague, Czech Republic

Important results:

Theory of the physical mechanism for negative corona discharge formation
Model of the formation and instabilities of high-pressure cathode region
Development of several types of atmospheric pressure plasma sources. Some of them are already produced commercially.
Patented constuction of a composite anode for generation of underwater corona discharge
Patented technique for plasma activation of PES cords

Current projects:

APVT - 013/2001
Novel plasma sources for environmentally friendly surface treatment of nonwoven fabrics
Project of slovak-american scientific-technical collaboration (2002-2005)
Head of project: Prof. RNDr. Mirko Černák, PhD.

VEGA - 1/1011/04
Unified model of electrical discharge formation at atmospheric pressure (2004-2006)
Head of project: Prof. RNDr. Mirko Černák, PhD.

APVT (APVV) – 20-033004
Study of atmospheric pressure plasma treatment of wooden surfaces
Head of project: Prof. RNDr. Mirko Černák, PhD.
Start of project: 2005

APVT (APVV) – 99-035004
Nanostructural modification of fibrous and textile materials
Head of project: Ing. Kabátová, VÚTCH – CHEMITEX, Žilina
Local supervisor: Prof. RNDr. Mirko Černák, PhD.
Start of project: 2005

Project of applied research AV – 4/0003/05
Low-temperature plasma sources for nano-technological adhesion modification of textile cords used in rubber industry
Head of project: Prof. RNDr. Mirko Černák, PhD.
Start of project: 2005

APVT (APVV) – 20/01505
Prototype device for continuous plasma activation of narrow thin webs
Head of project: RNDr. Anna Zahoranová, PhD
Start of project: 2005

References:

Černák M., Hosokawa T., and Inoshima M.:"Positive-streamer- like phemonema in short corona gaps", Appl. Phys. Letters 57(1990)339.
Černák M., van Veldhuizen E.M., Morva I., Rutgers W.R.:"Effect of cathode surface properties on glow-to-arc transition in a short positive corona gap in ambient air", J.Phys.D: Appl. Phys.28(1995) 1126-32.
Odrobina I., Černák M.:"Numerical simulation of streamer-cathode interaction" J.Appl. Phys. 78(1995)3635-42.
A. Zahoranová, M. Štefečka, M. Černák, V. Šurda: Prebreakdown positive corona streamers and the streamer-cathode contact in hydrogen, Czech. J. Phys. 49(1999) 941 - 956.
Černák M. and Hosokawa T.:"Complex form of current pulses in negative corona discharges" Phys. Rev. A 43(1991)1107.
Černák M., Hosokawa T., and Odrobina I.:"Experimental confirmation of positive-streamer-like mechanism for negative corona curent pulse rise" J. Phys.D: Appl. Phys. 26(1993)607.
Černák M., T. Hosokawa, S. Kobayashi, T. Kaneda "Streamer mechanism for negative corona current pulses" J. Appl. Phys. 83 (1998)5678-90.
A.Zahoranová, J. Kúdelčík, J. Paillol, and M. Černák: Ionization and electron emission processes active in negative corona current pulse in N2-SF6 mixturesJ. Phys. D: Appl. Phys. 35 (2002), 762-769.
A. Zahoranova, J. Kúdelčík, M. Šimor, M. Černák:“Mechanism for negative corona current pulses in CO2-SF6 mixtures“ J. Phys. D 36 (2003) L39-L41
Štefecka M., Rahel J., Černák M., I. Hudec, M. Mikula, M. Mazur:"Atmospheric-pressure plasma treatment of ultralight molecular weight polyethylene fibers" Journal of Materials Science Letters 18 (1999) 2007.
Štefecka M., Rahel J., I. Hudec, P. Janypka, M. Černák., M. Kando: "Atmospheric-pressure plasma treatment of polyester monofilaments for rubber reinforcement" Journal of Materials Science Letters 19 (2000) 1869.
M. Černák, J. Ráhel, I.Hudec, M. Štefečka, M. Kando, I.Chodák: Surface modification of polyester monofilaments by atmospheric-pressure plasma“, Plasmas and Polymers 5(2000)119
J.Rahel, M. Šimor, M. Černák, M. Štefečka, Y. Imahori, M. Kando: Hydrophilization of polypropylene nonwoven fabric using surface barrier discharge. Surface and Coating Technology 169 (2003) 604-609
E.G. Finantu-Dinu, B.T. Kim, M. Černák, A. Schwabedissen and J. Engemann: "Improving the wettability of chromium coated plates by atmospheric air plasma treatment" Surface and Coating Technology 174 (2003) 553-558
M. Šimor, J. Rahel ,M. Černák,Y. Imahori, M. Štefečka, and M. Kando:”Atmospheric-pressure plasma treatment of polyester nonwoven fabrics for electroless metal plating” Surface and Coating Technology 172/1 (2003)1 – 6
M. Šimor, J. Rahel, P. Vojtek, A. Brablec, M. Černák:”Atmospheric-pressure diffuse coplanar surface discharge for surface treatments” Appl. Phys. Lett. 81(2002) 2716-2718
Rahel' J, Šimor M, Černák M, Štefečka M, Imahori Y, Kando M:”Hydrophilization of polypropylene nonwoven fabric using surface barrier discharge” 169 (2003)604-608
M. Šimor, J. Rahel, P. Vojtek, A. Brablec, M. Černák:”Atmospheric-pressure diffuse coplanar surface discharge for surface treatments” Appl. Phys. Lett. 81(2002) 2716-2718.
M. Černák, J. Rahel, D.Kovacik, M. Šimor, A. Brablec, P. Slavicek: “ Generation of Thin Surface Plasma Layers for Atmospheric-Pressure Surface Treatments“ Contrib. Plasma Phys. 44 (2004) 504 – 507.
Šunka P., Babický V., Člupek M., Lukeš P., Šimek M., Schmidt J., Černák M.:"Generation of chemically active species by electrical discharges in water", Plasma Sources Sci.Technol. 8 (1999)258.
A. Brablec, P. Slavíček, P. Stahel, T. Cizmar, D. Trunec, M. Šimor, M. Černák: “Underwater pulse electrical diaphragm discharge for surface treatment of fibrous polymeric materials” Czech. J. Phys, 52 (2002), Suppl. D, pp. 491-500.