Lubomír KOPERA

  • 2024

Kováč, P., Búran, M., and Kopera, L.: Essential properties of sub-cooled water ice and background field properties of MgB2 coil measured in it, Cryogenics 141 (2024) 103897.

Hušek, I., Kováč, P., Melišek, T., Berek, D., and Kopera, L.: Effects of interface angle, added powder and applied deformation on the transport current and structure of scarf joints of single- and multi-core unreacted MgB2 wires, Supercond. Sci Technol. 37 (2024) 37 075016.

  • 2023

Búran, M., Kopera, L., Melišek, T., and Kováč, P.: E–I characteristics and critical currents of small Bi-2223/Ag coil thermally stabilized by solid and liquid nitrogen compared to water ice, Supercond. Sci Technol. 36 (2023) 105013.

Búran, M., Kováč, P., Kopera, L., and Hušek, I.: Thermal stability of 6-filament MgB2 wire with resistive CuNi sheath cooled by liquid He and water ice, Cryogenics 133 (2023) 103694.

  • 2022

Kováč, J., Kopera, L., Pardo, E., Melišek, T., Ries, R., Berberich, E., Wolfstädler S., and Reis, T.: Measurement of AC loss down to 25 K in a REBCO racetrack coil for electrical aircraft motor, Sci Reports 12 (2022) 16454.

Kováč, P., Kopera, L., Berek, D., Hain, M., Melišek, T., Hušek, I., Kováč, J., and Búran, M.: High-current-density Rutherford MgB2 cable sheathed by CuNi30 alloy, Supercond. Sci Technol. 35 (2022) 115003.

Búran, M., Kopera, L., and Kováč, P.: Transport measurement of MgB2 wire under the sub-cooled water ice compared to other cooling conditions, Supercond. Sci Technol. 35 (2022) 105004.

Kováč, P., Búran, M., and Kopera, L.: Behaviour of Al2O3-oxide insulated and non-insulated superconducting MgB2 coils cooled by water ice, Supercond. Sci Technol. 35 (2022) 095007.

Kováč, P., Kopera, L., Melišek, T., Búran, M., Hušek, I., Berek, D., and Kováč, J.: Water ice-cooled MgB2 coil made by wind and react process, Supercond. Sci Technol. 35 (2022) 055001.

  • 2021

Búran, M., Kováč, P., Kopera, L., and Melišek, T.: I-V characteristics of MgB2 conductors with different metallic sheaths, Cryogenics 120 (2021) 103370.

Kováč, P., Hušek, I., Hain, M., Kopera, L., Melišek, T., and Berek, D.: Longitudinal uniformity of MgB2 wires made by an internal magnesium diffusion process, Supercond. Sci Technol. 34 (2021) 095007.

Kováč, P., Kováč, J., Perez, N., Scheiter, J., Búran, M., Kopera, L., Hušek, I., Melišek, T., and Berek, D.: Low‐purity Cu and Al sheathed multi‐core MgB2 wires made by IMD process, Supercond. Sci Technol. 34 (2021) 075010.

Kováč, J., Kapolka, M., Kováč, P., Kopera, L., Pardo, E.,  Zhu, Y.C., Yao, C., and Ma, Y.: Magnetization AC losses of iron-based Ba-122 superconducting tapes, Cryogenics 116 (2021) 103281

  • 2020

Kováč, P., Kopera, L., Hain, M., Martínez, E., Kováč, J., Melišek, T., Berek, D., and Hušek, I.: MgB2 cables made of thin wires manufactured by IMD process, Supercond. Sci Technol. 33 (2020) 085004.

Kováč, P., Hušek, I., Pérez, N., Rosová, A., Berek, D., Gelušiaková, B., Kopera, L., Melišek, T., and Nielsch, K.: Structure and properties of barrier-free MgB2 composite wires made by internal magnesium diffusion process, J. Alloys Comp. 829 (2020) 154543.

  • 2019

Kopera, L., Kováč, P., Kováč, J., Melišek, T., Hušek, I., and Berek, D.: Small diameter wind and react coil made of anodised Al-sheathed MgB2 wire, Supercond. Sci Technol. 32 (2019) 105003.

Kováč, P., Bonura, M., Santra, S., Kopera, L., Rosová, A., Senatore, C., and Hušek, I.: Thermal conductivities and thermal runaways of superconducting MgB2 wires stabilized by an Al+Al2O3 sheath, Supercond. Sci Technol. 32 (2019) 115007.

Santra, S., Grovenor, C.R.M., Speller, S.C., Kováč, P., Kopera, L., and Hušek, I.: Comparison of interfacial and critical current behaviour of Al+Al2O3 sheathed MgB2 wires with Ta and Tidiffusion barriers, J. Alloys Comp. 807 (2019) 151665.

Búran, M., Vojenčiak, M., Mošať, M., Ghabeli, A., Solovyov, M., Pekarčíková, M., Kopera, Ľ., and Gömöry, F.: Impact of a REBCO coated conductor stabilization layer on the fault current limiting functionality, Supercond. Sci Technol. 32 (2019) 095008.

Kováč, P., Kopera, L., Kováč, J., Melišek, T., Haessler, W., Wang, D., and Ma, Y.: Current densities and strain tolerances of filamentary MgB2 wires made by an internal Mg diffusion process, Supercond. Sci Technol. 32 (2019) 095006.

Kováč, P., Hušek, I., Rosová, A., Melišek, T., Kováč, J., Kopera, L., Scheiter, J., and Haessler, W.: Strong no-barrier SS sheathed MgB2 composite wire, Physica C 560 (2019) 40-44.

  • 2018

Kováč, J., Kulich, M., Kopera, L., and Kováč, P.: AC losses of Rutherford MgB2 cables made by powder-in-tube and internal magnesium diffusion processes, Supercond. Sci Technol. 31 (2018) 125014.

Kováč, P., Hušek, I., Kulich, M., Kováč, J., Melišek, T., Kopera, L., and Pachla, W.: Multi-core MgB2 wire with a Ti barrier and a reinforced Al+Al2O3 sheath, Supercond. Sci Technol. 31 (2018) 095006.

Kováč, P., Hušek, I., Rosová, A., Kulich, M., Kováč, J., Melišek, T., Kopera, L., Balog, M., and Krížik, P.: Ultra-lightweight superconducting wire based on Mg, B, Ti and Al, Sci Reports 8 (2018) 11229.

Balog, M., Rosová, A., Szundiová, B., Orovčík, Ľ., Krížik, P., Švec, P.Jr., Kulich, M., Kopera, L., Kováč, P., Hušek, I., and Ibrahim, A.M.H.: HITEMAL-an outer sheath material for MgB2 superconductor wires: The effect of annealing at 595–655 °C on the microstructure and properties, Mater. Design 157 (2018) 12–23.

Kováč, P., Hušek, I., Kulich, M., Kováč, J., Melišek, T., Kopera, L., Perez, N., Haessler, W., Balog, M., Krížik, P., and Berek, D.: Lightweight MgB2 wires with a high temperature aluminum sheath made of variable purity Al powder and Al2O3 content, Supercond. Sci Technol. 31 (2018) 085003. (APVV 14-0522, VEGA 2/0025/14)

Rosová, A., Hušek, I., Kulich, M., Melišek, T., Kováč, P., Dobročka, E., Kopera, L., Scheiter, J., and Haessler, W.: Microstructure of undoped and C-doped MgB2 wires prepared by an internal magnesium diffusion technique using different B powders, J. Alloys Comp. 764 (2018) 437e445.

Kováč, P., Kopera, L., Kováč, J., Hain, M., Melišek, T., Kulich, M., and Hušek, I.: Rutherford cable made of internal magnesium diffusion MgB2 wires sheathed with Al-Al2O3 particulate metal matrix composite, Supercond. Sci Technol. 31 (2018) 015015.

Cubero, A., Navarro, R., Kováč, P., Kopera, L., Rindfleisch, M., and Martínez, E.: Quench dynamics in MgB2 Rutherford cables, Supercond. Sci Technol. 31 (2018) 045009.

  • 2017

Kopera, Ľ., Kováč, P., Kulich, M., Melišek, T., Rindfleisch, M., Yue, J., Hušek, I., : Critical currents of Rutheford MgB2 cables compacted by two-axial rolling. Supercond. Sci Technol. 30 (2017) 015002.

Kováč, P., Kulich, M., Kopera, Ľ., Melišek, T., Kováč, J., Hušek, I., : Filamentary MgB2 wires manufactured by different processes subjected to tensile loading and unloading. Supercond. Sci Technol. 30 (2017) 065006.

Kováč, P., Hušek, I., Melišek, T., Kulich, M., Rosová, A., Kováč, J., Kopera, Ľ., Balog, M., Krížik, P., Orovčík, Ľ., : Lightweight Al-stabilized MgB2 conductor made by the IMD process. Supercond. Sci Technol. 30 (2017) 115001.

Kováč, P., Balog, M., Hušek, I., Kopera, Ľ., Krížik, P., Rosová, A., Kováč, J., Kulich, M., Čaplovičová, M., :Properties of near- and sub-micrometre Al matrix composites strengthened with nano-scale in-situ Al2O3 aimed for low temperature applications. Cryogenics 87 (2017) 58–65.

Hušek, I., Kováč, P., Melišek, T., Kulich, M., Rosová, A., Kopera, Ľ., Szundiová, B., : Superconducting MgB2 wires with vanadium diffusion barrier. Supercond. Sci Technol. 30 (2017) 105008.

  • 2016

Kováč, P., Hušek, I., Melišek, T., Kulich, M., Kopera, Ľ., : Bending strain tolerance of a MgB2 superconducting wires. Supercond. Sci Technol. 29 (2016) 045002.

Kováč, P., Hušek, I., Pachla, W., Melišek, T., Kulich, M., Rosová, A., Kopera, Ľ., : Effect of cold isostatic pressing on the transport current of filamentary of MgB2 wire made by the IMD process. Supercond. Sci Technol. 26 (2016) 075004.

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., Kulich, M., : Fast creation of dense MgB2 phase in wires made by IMD process,. Supercond. Sci Technol. 26 (2016) 10LT01.

Kováč, P., Hušek, I., Kováč, J., Melišek, T., Kulich, M., Kopera, Ľ., : Filamentary MgB2 wires with low magnetization AC losses. IEEE Trans. Applied Supercond. 26 (2016) 6200705.

Kováč, P., Hušek, I., Kulich, M., Melišek, T., Kováč, J., Kopera, Ľ., : MgB2 wires with Ti and NbTi barrier made by IMD process. Cryogenics 79 (2016) 74-78.

  • 2015

Kováč, P., Kopera, Ľ., Melišek, T., Kulich, M., Hušek, I., Lin, H., Yao, C., Zhang, X., Ma, Y., :Electromechanical properties of iron and silver sheathed Sr0.6K0.4Fe2As2 tapes. Supercond. Sci Technol. 28 (2015) 035007.

Kováč, P., Hušek, I., Rosová, A., Kulich, M., Melišek, T., Kopera, Ľ., Dobročka, E., : Interface MgB2 layers made by magnesium diffusion into boron. In: Progress in Applied Surface, Interface and Thin Film Sci. 2015 – SURFINT-SREN IV. Extend. Abstract Book. Ed. R. Brunner. Bratislava: CU 2015. ISBN: 978-80-223-3975-9. P. 84.

Kováč, P., Hušek, I., Rosová, A., Kulich, M., Melišek, T., Kopera, Ľ., Brunner, B., : Properties of MgB2 wires made by internal magnesium diffusion into different boron powders. Supercond. Sci Technol. 28 (2015) 095014.

Kováč, P., Kopera, Ľ., Melišek, T., Sarmiento, G., Sanz Castillo, S., Brisigotti, S., Nardelli, D., Tropeano, M., :Tensile and bending strain tolerance of ex-situ MgB2/Ni/Cu superconductor tape. IEEE Trans. Applied Supercond. 25 (2015) 6200607.

  • 2014

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., Kováč, J., : Critical currents, Ic-anisotropy and stress tolerance of MgB2 wires made by internal magnesium diffusion. Supercond. Sci Technol. 27 (2014) 065003.

Kováč, P., Kopera, Ľ., Melišek, T., Hušek, I., : Electro-mechanical behaviour of in situ W added MgB2 wire. Cryogenics 60 (2014) 5-8.

Skákalová, V., Vretenár, V., Kopera, Ľ., Kotrusz, P., Mangler, C., Meško, M., Meyer, J., Hulman, M., :Electronic transport in composites of graphite oxide with carbon nanotubes. Carbon 72 (2014) 224-232.

Hossain, M., Motaman, A., Barua, S., Patel, D., Mustapic, M., Kim, J., Maeda, M., Rindfleisch, M., Tomsic, M., Çiçek, O., Melišek, T., Kopera, Ľ., Kario, A., Ringsdorf, B., Runtsch, B., Jung, A., Dou, S., Goldacker, W., Kováč, P., : The rolel of CHPD: superior critical current density and n-value obtained in binary in situ MgB2 cables. Supercond. Sci Technol. 27 (2014) 095016.

  • 2013

Kováč, P., Kopera, Ľ., Melišek, T., Rindfleisch, M., Haessler, W., Hušek, I., : Behaviour of filamentary MgB2 wires subjected to tensile stress at 4.2 K. Supercond. Sci Technol. 26 (2013) 105028.

Rosová, A., Kováč, P., Hušek, I., Kopera, Ľ., : Composition changes in thin-filament MgB2/Ti/GlidCop® wires heat treated at variable periods,. J. Alloys Compounds 572 (2013) 25-30.

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., Polák, M., : Filamentary MgB2 superconductors with titanium barriers. J. Supercond. Novel Magnet. 26 (2013) 2109-2114.

Kováč, P., Hušek, I., Kopera, Ľ., Melišek, T., Rosová, A., Dobročka, E., : Properties of in situ made MgB2 in Nb or Ti sheath. Supercond. Sci Technol. 26 (2013) 025007.

Kopera, Ľ., Kováč, P., Hušek, I., Melišek, T., : Rutherford cable made of single-core MgB2 wires. Supercond. Sci Technol. 26 (2013) 125007.

  • 2012

Kopera, Ľ., Kováč, P., Hušek, I., : Calculated and measured normal state resistivity of 19-filament MgB2/Ti/Cu/stainless steel wire. Supercond. Sci Technol. 25 (2012) 025021.

Kováč, P., Kopera, Ľ., : Electromechanical properties of filamentary MgB2 wires. IEEE Trans. Applied Supercond. 22 (2012) 8400106.

Kováč, P., Melišek, T., Kopera, Ľ., Kováč, J., Hušek, I., : Selected properties of GlidCop® sheathed MgB2 wires. Supercond. Sci Technol. 25 (2012) 095008.

  • 2011

Polák, M., Demenčík, E., Hušek, I., Kopera, Ľ., Kováč, P., Mozola, P., Takács, S., : AC losses and transverse resistivity in filamentary MgB2 tape with Ti barriers. Physica C 471 (2011) 389-394. (VEGA 2/0037/09). (APVV 0398-07).

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., : Current densities of thin filament MgB2/Ti/GlidCop® wire. Supercond. Sci Technol. 24 (2011) 105006. (VEGA 2/0037/09).

Rosová, A., Kováč, P., Hušek, I., Kopera, Ľ., : EDX and ion beam treatment studies of filamentary in situ MgB2 wires with Ti barrier. J. Alloys Compounds 509 (2011) 7961-7967.

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., : Filamentary MgB2 wire twisted before and after heat treatment. Supercond. Sci Technol. 24 (2011) 115006.

Rostila, L., Demenčík, E., Šouc, J., Brisigotti, S., Kováč, P., Polák, M., Grasso, G., Lyly, M., Stenvall, A., Tumino, A., Kopera, Ľ., : Magnesium diboride wires with nonmagnetic matrices – AC loss measurements and numerical calculations. IEEE Trans. Applied Supercond. 21 (2011) 3338-3341.

Kováč, P., Martinez, E., Melišek, T., Kopera, Ľ., Hušek, I., : Stability of multi-core MgB2/Ti/Cu/SS wires. Cryogenics 51 (2011) 16-20.

Hušek, I., Kováč, P., Melišek, T., Kopera, Ľ., : Thermally stabilized MgB2 composite wires with different barriers. Cryogenics 51 (2011) 550-554. (APVV 0495-10). (VEGA 2/0037/09).

  • 2010

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., Reissner, M., : Cu stabilized MgB2 composite wire with an NbTi barrier Supercond. Sci Technol. 23 (2010) 025014. (VEGA 2/0037/09).

Rosová, A., Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., Šmatko, V., Vávra, I., : Difúzia materiálu v supravodivých kábloch analyzovaná pomocou zariadenia Quanta 3D, Technika 8 (2010) 48-49.

Kováč, P., Hušek, I., Rosová, A., Melišek, T., Kopera, Ľ., : Fine-filamentary in situ MgB2 wires. Supercond. Sci Technol. 23 (2010) 105006.

Kováč, P., Hušek, I., Melišek, T., Kopera, Ľ., Reissner, M., : Stainless steel reinforced multi-core MgB2 wire subjected to variable deformations, heat treatments and mechanical stressing. Supercond. Sci Technol. 23 (2010) 065010.

  • 2009

Kováč, P., Melišek, T., Kopera, Ľ., Hušek, I., Polák, M., Kulich, M., : Progress in electrical and mechanical properties of rectangular MgB2 wires. Supercond. Sci Technol. 22 (2009) 075026.

Hušek, I., Kováč, P., Melišek, T., Kopera, Ľ., : Transport current densities of MgB2 wires, cable and continually transposed conductor. Cryogenics 49 (2009) 366-370.

  • 2008

Kopera, Ľ., Kováč, P., Melišek, T., : Electromechanical characterization of selected superconductors. Supercond. Sci Technol. 21 (2008) 115001.

Kopera, Ľ., Šmatko, V., Prusseit, W., Polák, M., Semerad, R., Štrbik, V., Šouc, J., : In situ patterning of filamentary YBCO coated conductors. Physica C 468 (2008) 2351-2355.

  • 2006

Kopera, Ľ., Kováč, P., Melišek, T., : Compact design of cryogen-free HTS magnet for laboratory use. IEEE Trans. Applied Supercond. 16 (2006) 1415-1418.

  • 2005

Kováč, P., Masti, M., Lehtonen, J., Kopera, Ľ., Kawano, K., Abell, S., Metz, B., Dhalle, M., : Comparison and analysis of Hall probe scanning, magneto-optical imaging and magnetic knife measurements of Bi-2223/Ag tape. Supercond. Sci Technol. 18 (2005) 805-812.

Kopera, Ľ., Melišek, T., Kováč, P., Pitel, J., : The design and performance of a Bi-2223/Ag magnet cooled by a single-stage cryocooler. Supercond. Sci Technol. 18 (2005) 977-984.

Oemry, F., Diantoro, M., Sutjahja, I., Tjia, M., Kopera, Ľ., Bonfait, G., Kováč, P., : Variation of vortex structure characteristics of Bi-2223/Ag superconducting tapes with respect to applied magnetic field direction. Physica C 426-431 (2005) 396-401.

  • 2002

Kováč, P., Hušek, I., Kopera, Ľ., Melišek, T., van Eck, H., Metz, B., ten Haken, B., : Electrical and mechanical properties of Bi-2223/Ag tapes made by TIRT technique. Physica C 372-376 (2002) 891-894.

Kováč, P., Hušek, I., Kopera, Ľ., van der Meer, O., Metz, B., ten Haken, B., Kvitkovič, J., Polák, M., :Transversal and longitudinal current distribution in Bi-2223/Ag tapes with high filament aspect ratio. Physica C 372-376 (2002) 916-918.

  • 2001

Vávra, I., Bydžovský, J., Flachbart, K., Tejada, J., Kopera, Ľ., Kováčová, E., Temst, K., Bruynseraede, Y., :Fe/Cr sensor for the milliKelvin temperature range. Sensors & Actuators A 91 (2001) 177-179.

Kováč, P., Hušek, I., Pachla, W., Diantoro, M., Bonfait, G., Maria, J., Fröhlich, K., Kopera, Ľ., Diduszko, R., Presz, A., : Material for resistive barriers in Bi-2223/Ag tapes. Supercond. Sci Technol. 14 (2001) 966-972.

  • 2000

Gömöry, F., Hušek, I., Kováč, P., Kopera, Ľ., : AC susceptibility, critical densities and AC losses of Bi-2223/Ag tapes in perpendicular AC magnetic field. In: Studies in High-Temperature Phys. Vol. 32. Ed. A.Narlikar. New York: Nova Sci. Publ. 2000. P. 63.

Kováč, P., Hušek, I., Kopera, Ľ., : Advanced rolling techniques for Bi(2223)/Ag wires and tapes IoP Conf. Ser. No. 167 (2000) 455-458.

Kováč, P., Cambel, V., Kopera, Ľ., Melišek, T., Pitel, J., Bukva, P., : Quality measurement of Bi(2223)/Ag tapes by Hall probe array IoP Conf. Ser. No. 167 (2000) 531-534.

  • 1999

Kováč, P., Cesnak, L., Melišek, T., Hušek, I., Bukva, P., Pitel, J., Kopera, Ľ., Pachla, W., Bucholtz, W., : Currents in series and parallel connections of small inner bore coils wound from Bi(2223)/Ag tapes and treated by the wind and react technique Supercond. Sci Technol. 12 (1999) 507-513.

  • 1998

Kopera, Ľ., Kováč, P., Hušek, I., : New rolling technique for texturing of Bi(2223)/Ag tapes Supercond. Sci Technol. 11 (1998) 433.

  • 1997

Kováč, P., Hušek, I., Kopera, Ľ., : Application oftwo-axial rolling for multicore Bi(2223)/Ag tapes Supercond. Sci Technol. 10 (1997) 982.

Kováč, P., Hušek, I., Kopera, Ľ., Pachla, W., : Optimalization of rolling process for multicore Bi(2223)/Ag tapes made by OPIT technique IoP Conf. Series No. 158 (1997) 1343.

Kopera, Ľ., Kováč, P., Cesnak, L., : Sample holder for measuring of Ic-anisotropy in high magnetic fields Supercond. Sci Technol. 10 (1997) 995.

  • 1996

Kováč, P., Kopera, Ľ., Hušek, I., Cesnak, L., : Bending of Bi(2223)/Ag tapes at 77K and 300K Supercond. Sci Technol. 9 (1996) 792.

Hušek, I., Kováč, P., Kopera, Ľ., : Study of BSCCO-core density in multicore Ag sheathed tapes by microhardnees profiles Supercond. Sci Technol. 9 (1996) 1066.

  • 1995

Kováč, P., Cesnak, L., Kopera, Ľ., Fikis, H., Hilscher, G., : Ic-anisotropy in flettened Nb3Sn superconductors and possible ways for overcoming it Cryogenics 35 (1995) 83.

  • 1986

Huťka, P., Kováč, P., Šetina, P., Chlebáková, K., Kopera, Ľ., Jergel, M., : Výskum stabilizovaných Nb3Sn mnohožilových supravodičov na EÚ CEFV SAV, Transformátory 64 (1986) 8.

  • 1985

Kopera, Ľ., Kováč, P., Jergel, M., Huťka, P., : Multifilamentary Nb3Sn superconductor with graphite diffusion barrier. In: Conf. Magnet Technol. Zürich: 1985. P. 497.

Huťka, P., Kováč, P., Šetina, P., Chlebáková, K., Kopera, Ľ., Jergel, M., : Vývoj stabilizovaných Nb3Sn supravodičov na ElÚ SAV, Elektrotechn. časopis 36 (1985) 870.