Greifswald 2024 – scientific programme

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P: Fachverband Plasmaphysik

P 6: Poster I

P 6.1: Poster

Monday, February 26, 2024, 16:30–18:30, ELP 6: Foyer

Thermo-Field emission from cathodes made of selected materials — •Margarita Baeva¹, Dirk Uhrlandt¹, Dominik Bratek², Carsten Uber², Bogdan Barbu³, and Frank Berger³ — ¹Leibniz Institute for Plasma Science and Technology (INP), Greifswald, Germany — ²Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany — ³Technische Universität Ilmenau, Germany

Electric discharges in a metal vapour released from the cathode during contact opening are observed in various application fields. In explosion protection, the ignition prediction in flammable gas mixtures is concerned with contact break discharges. The latter represent an ignition source for the gas mixture. In low-voltage switching devices, an electric arc in metal vapour occurs during the so called immobility phase, which is essential for the breaking performance of the device.
This contribution is concerned with the emission of electrons from cathodes made of selected materials (Cu, W, Cd, Zn, Ir) that occurs by collective effects (high temperature in the cathode, high electric field on the cathode surface). These effects characterize the arc regime of operation of electric discharges. In order to obtain the electron emission current for operation with cathodes of the aforementioned materials, the transferred matrix method is applied. This method is applicable to arbitrary shapes of the surface potential barrier. The selected materials considered in this work represent both refractory and non-refractory cathodes.

Keywords: electron emission; cathode; arc regime