When a femtosecond duration and hundreds of kiloampere peak current electron beam traverses the vacuum high-density plasma interface, new process, that we call relativistic transition radiation (RTR), generates an intense $\ensuremath{\sim}100$ as pulse containing $\ensuremath{\sim}1$ terawatt power coherent ultraviolet (VUV) accompanied by several smaller satellite pulses. This inherits radial...

When a physical object ("a source") without its own eigenfrequency moves through an acoustically homogeneous medium, the only possible form of acoustic radiation is the emission of Mach shock waves, which appear when the source velocity surpasses sonic speed. In nonhomogeneous media, in nonstationary media, or in the neighborhood of such media, the source motion is accompanied by the so-called ...