WAA Lecture December 10, 7:30 p.m.


Massimo Capasso, Ph.D.
Columbia University & VERITAS Array at Fred Whipple Observatory, Arizona

Single-photon technologies for ground-based gamma-ray astronomy

 Gamma rays from space can reach energies up to several trillion times those of visible light, in dramatically explosive phenomena that shape the Universe as we know it. At these energies, the observable fluxes so low that very large collection areas or long observing times are needed to reach a significant detection. For both these reasons, space-born instruments are not suited for the detection of Very-High-Energy (VHE) gamma rays; instead, ground-based observatories can exploit the atmosphere as a huge detector to observe VHE gamma rays indirectly. The light that is emitted as a by-product of the interaction of gamma rays and the atmosphere is very faint and very fast (on the scale of billionths of seconds). Therefore, extremely sensitive detectors coupled with fast electronics are the enabling technology for ground-based gamma-ray astronomy.

In this talk, Dr. Capasso will present an overview of the physics that produces VHE gamma rays in space, of how to detect them on the ground and of the latest single-photon solid-state technology that enables such technique: Silicon photomultipliers (SiPMs).