When these gamma rays reach the Earth's atmosphere they are absorbed, producing a short-lived shower of secondary particles that emit weak flashes of bluish light known as
Cherenkov radiation, lasting just a few billionths of a second.
This, in turn, creates an optic shock wave called
Cherenkov radiation, which resembles something like a cone of light.
Detecting this so-called
Cherenkov radiation from muons is particularly revealing: from the data, scientists deduce the travel direction and the energy of the muon and, thus, of the original neutrino.
The features seen can be described in terms of soliton fission and dispersive wave emission in time domain while in terms of self-phase modulation and
Cherenkov radiation in spectral domain, respectively.
Metamaterial exhibits some novel electromagnetic and optical properties which are not found in nature media, for example, negative refraction, reversals of both Doppler shift and
Cherenkov radiation [2], enhancement of evanescent wave, and subwavelength imaging [6].
Negative refractive index (NRI) metamaterials with simultaneously negative permittivity and negative permeability are currently the focus of a great deal of interest due to their unique electromagnetic properties such as the reversals of both Doppler shift and
Cherenkov radiation, enhancement of evanescent wave, and subwavelength resolution imaging, etc.
It was expanded in 2009 to span 1 square kilometer, becoming the world's biggest
Cherenkov radiation detector.
Muons from high-energy neutrinos (energy range between [10.sup.11] and [10.sup.16] eV) radiate blue light, which is the so-called
Cherenkov radiation. In transparent ice or clear water this light can be detected by optical sensors like photomultiplier tubes.
Those PMTs can sense the blue
Cherenkov radiation that is generated during the rare event of a high-energy neutrino entering the planet from the Northern Hemisphere, passing completely through it, then colliding with a water molecule in the ice sheet in the vicinity of the detector.
Cherenkov radiation occurs when electrons move in a medium with a speed greater than the phase speed of electromagnetic waves in the medium.