Benilov, M. S.Cunha, M. D.Hartmann, W.Wenzel, N.2022-09-022022-09-022014Benilov, M. S., Cunha, M. D., Hartmann, W., & Wenzel, N. (2014). Numerical investigation of the stability of stationary solutions in the theory of cathode spots in arcs in vacuum and ambient gas. Plasma Sources Science and Technology, 23(5), 054007.http://hdl.handle.net/10400.13/4553The stability of stationary spots on cathodes of arcs in vacuum and ambient gas is investigated by means of the simulation of the temporal evolution of perturbations imposed over steady-state solutions. Two cases of loading conditions are considered, namely, spots operating at a fixed current (the case typical of small-scale experiments) and spots operating at a fixed voltage (the case typical of high-power circuit breakers). Results are reported on spots on large copper cathodes of vacuum arcs and on spots on tungsten cathodes of high-pressure argon arcs. It is shown, in particular, that if the ballast resistance in small-scale laboratory experiments with a high-current arc is insufficient, the potential consequence may be a thermal explosion of a spot, if the arc burns in vacuum, and massive melting of the cathode surface, if the arc burns in ambient gas. This conclusion conforms to trends observed in the experiment.engStabilityCathode spotsStationary solutionsArcs in vacuum and ambient gas.Faculdade de ciências Exatas e da Engenhariajournal article10.1088/0963-0252/23/5/054007