IceCube Project Overview
We are all familiar with traditional telescopes that use light to look into the cosmos. But the problem with light is that it interacts with so readily with matter! This makes it easy to detect, it also means there must be a clear line of sight to the object being studied. Light can be absorbed, and scattered before it finds its way to our telescopes. So, other means of seeing into the far reaches of space are required.
The IceCube project will use a one cubic kilometer volume of ice in Antarctica to explore the universe using subatomic particles known as neutrinos. Neutrino's are emitted during high-energy events in the universe and can be used to track down the location and gain a better understanding of them. As a fundamental particle, it reacts only by the weak nuclear force. The neutrinos reluctance to interact makes it possible to escape from the dense interior of stars and pass through matter on the way to our detector. It is able to cross vast distances without changing its course. Such a particle is truly invaluable and can be used to find information about events far away. But how do you detect a neutrino?
We detect the presence of neutrinos when they collide with another particle. Neutrinos come in three “flavors” but we will focus on the muon neutrino. The collision of the muon neutrino with a proton or neutron inside an atom produces a muon that stays on virtually the same path as the colliding neutrino. A muon is a particle similar to an electron with the same charge, but the muon is about 200 times more massive. Traveling in ice the muon produces Cerenkov radiation (a bluish light) that is detectable by IceCube.
The DOM (Digital Optical Module) is IceCube's means of detecting this radiation. They will be deployed on over 80 strings that have been placed in holes spaced 125 meters apart on a triangular grid. Each string will have 60 doms spaced every 17 meters at depths ranging from 1450 - 2450 meters. IceCube takes advantage of Antarctica's exceptionally pure ice to detect the muon's radiation. Each DOM records the lights intensity and the time it was detected to within a few billionths of a second, and sends that information to the surface to be analyzed.
IceCube is based on its predecessor AMANDA (Antarctic Muon And Neutrino Detector Array). AMANDA was a prototype neutrino detector about 50 times smaller than IceCube. IceCube also includes a surface array known as IceTop to study cosmic rays. As with all new investigations, the true nature of what will be discovered is up in the air. IceCube is scheduled to be completed in 2011, but analysis has already started using the DOM's that have already been deployed.
For more information please visit the official IceCube website.