Abstract <p>Explosive emission processes are of great importance in electrodynamic and accelerating structures exposed to high-power radio-frequency electromagnetic waves. These processes emerge due to the explosion of microprotrusions on the surface of electrodes. The paper presents the results of radiation magnetohydrodynamic calculations of the explosion of copper conductors under conditions similar to those that arise during the explosion of microprotrusions. This means that the current density is about 10⁹ A/cm². Quasi-stationary and radio-frequency explosion regimes are considered. It turns out that in both cases the maximum of the spectral distribution lies in the ultraviolet range. However, the radiation power that comes out of the conductor in the radio frequency regime is almost two orders of magnitude less than that in the quasi-stationary regime.</p>