One technique for the detection of neutrinos from outer space involves the reaction of neutrinos with deuterium in a water tank, with the resulting high-speed electron then generating Cherenkov radiation in the water. How is the Cherenkov radiation produced?
A) by the passage of the charged electron through the water at a speed greater than the speed of light in a vacuum
B) by the recombination of the electron with a proton to produce neutral hydrogen and Balmer series line emissions
C) by the annihilation of a positron in the water by the electron
D) by the charged electron moving in the water faster than the speed of light in water

Question

Quizplus · Accepted Answer

Cherenkov radiation is produced when a charged particle, such as an electron, moves through a dielectric medium (like water) at a speed greater than the phase velocity of light in that medium. This does not mean the particle exceeds the speed of light in a vacuum, which is a universal constant and the maximum speed at which all energy, matter, and information in the universe can travel. The phenomenon is specific to the medium's optical properties and is not related to the speed of light in a vacuum, recombination processes, or positron annihilation.

One Technique for the Detection of Neutrinos from Outer Space