Detection techniques of μs gamma-ray bursts using ground-based telescopes

We propose to use imaging atmospheric Cherenkov telescopes (IACTs) to search for cosmic bursts of E>200 MeV γ-ray emission. This energy regime has been the domain of the space based EGRET detector on the Compton Gamma Ray Observatory (CGRO), providing a good sensitivity for bursts lasting for more than 200 ms. Theoretical predictions of high-energy γ-ray bursts produced by quantum-mechanical decay of primordial black holes (Hawking 1971) suggest the emission of bursts on shorter time scales, lasting for a tenth of a microsecond or longer depending on particle physics. Upcoming next generation IACTs have the potential to detect microsecond scale γ-ray bursts, an observational window which is virtually unexplored. We discuss a technique, which is based on the detection of multi-photon-initiated air showers providing a sensitivity for bursts lasting nanoseconds to several microseconds