Experimental study of electromagnetic radiation from a faster-than-light vacuum macroscopic source

The effect which manifests itself in the form of directed electromagnetic pulses (EMP) initiated by an X-ray incident obliquely upon a conducting surface has been confirmed and investigated experimentally in detail. A planar accelerating diode comprising a metallic cathode and grid anode was initiated with an oblique short soft-X-ray pulse from a point laser-plasma source. Then a source of directed EMP-a current of accelerated photoelectrons-was formed whose boundary ran along the anode external surface with a faster-than-light velocity. The plasma was formed when short-pulse (similar to 0.3 ns) laser radiation from ISKRA-5 facility was focused on a plane Au target. The amplitude-in-time and spatial characteristics of radiation emitted by the faster-than-light source have been measured. Parameters of the accelerated electron current have been measured too. (C) 2006 Published by Elsevier Ltd.