Generation of cherenkov superradiant pulses with correlated phases defined by sharp edges of high-current electron bunches
Recently coherent summation of several SR pulses generated in parallel channels has been demonstrated in X- and Ka wavelength bands. This possibility is caused by picosecond stability of explosive emission from a cold cathode and strong correlation of phase of the SR pulses with respect to the leading edge of the electron bunch. In fact stimulated SR emission is initiated by spontaneous mission from bunch leading edges. In report we describe results of recent experiments and develop a theoretical model which covers both spontaneous and stimulated Cherenkov emission.
A coherent two-channel source of Cherenkov superradiance pulses
A two-channel source of Cherenkov superradiance pulses with the electron-wave systems of identical geometry which is capable of producing 2 × 0.3 GW pulses of duration 2 ns and center frequency 10 GHz has been developed and explored. The channels are powered by a high-voltage driver whose pulse is split into two pulses that are sent through parallel transmission lines. To shorten the voltage rise time in each channel, identical NiZn ferrite-loaded coaxial transmission lines with independently controlled axial bias fields are used.
Can Centauros or Chirons BE the First Observations of Evaporating Mini Black Holes
We argue that the signals expected from the evaporation of mini black holes — predicted in TeV-gravity models with large extra dimensions, and possibly produced in ultrahigh energy collisions in the atmosphere — are quite similar to the characteristics of the Centauro events, an old mystery of cosmic-ray physics.