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Publication
Numerical simulation of the initial stage of unipolar arcing in fusion-relevant conditions
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Advisor(s)
Abstract(s)
A model for the initial phase of unipolar arcing has been developed with account of an
external energy source which triggers the arcing, the vaporization of the atoms from the heated
surface, the ions and electrons produced by ionization of the vapor, the electron emission from
the metal surface, and melt motion and surface deformation. Current transfer outside the arc
attachment is taken into account and the potential difference between the plasma and the metal
surface (the plate) is evaluated from the condition that the net current transferred to the plate is
zero at each moment. The model is used for simulation of the interaction of an external energy
load (laser beam) with a tungsten plate immersed in a helium background plasma. The results
revealed the formation of a crater, but no jet formation or droplet detachment. If the plate is large
(R = 100 mm), the peak temperature attained is 5200 K, and the plate potential remains below
the plasma potential. If the plate is small (R = 10 mm), a peak temperature of 7500 K is reached,
the potential of the plate surpasses the plasma potential, circulation of the melt at the pool
periphery occurs, and the erosion (which is mainly due to the vaporization of the metal atoms in
the spot) reaches the value of 37 μg.
Description
Keywords
Unipolar arcs Plasma-electrode interaction Arc discharges . Faculdade de Ciências Exatas e da Engenharia
Citation
Kaufmann, H. T. C., Silva, C., & Benilov, M. S. (2019). Numerical simulation of the initial stage of unipolar arcing in fusion-relevant conditions. Plasma Physics and Controlled Fusion, 61(9), 095001. https://doi.org/10.1088/1361-6587/ab2fac
Publisher
IOP Publishing