Similar to its predecessor, the Antarctic Muon And Neutrino Detector Array (AMANDA), IceCube consists of spherical optical sensors called Digital Optical Modules (DOMs), each with a photomultiplier tube (PMT)[4] and a single-board data acquisition computer which sends digital data to the counting house on the surface above the array.

[5] DOMs are deployed on strings of 60 modules each at depths between 1,450 and 2,450 meters into holes melted in the ice using a hot water drill.

IceCube is designed to look for point sources of neutrinos in the teraelectronvolt (TeV) range to explore the highest-energy astrophysical processes.

Construction began in 2005, when the first IceCube string was deployed and sufficient data was collected to verify that the optical sensors functioned correctly.

[7] In the 2005–2006 season, an additional eight strings were deployed, making IceCube the largest neutrino telescope in the world.

The observatory will be able to detect more sources of particles, and discern their properties more finely at both lower and higher energy levels.

Each of the above steps requires a certain minimum energy, and thus IceCube is sensitive mostly to high-energy neutrinos, in the range of 107 to about 1021 eV.

[16] Realistically, an experimenter would need more space than just one DOM to the next to distinguish two cascades, so double bang searches are centered at PeV scale energies.

[17] One can also use machine learning (ML) techniques, such as Convolutional Neural Networks, to distinguish the tau neutrino signal.

[18][19] There is a large background of muons created not by neutrinos from astrophysical sources but by cosmic rays impacting the atmosphere above the detector.

Estimates predict the detection of about 75 upgoing neutrinos per day in the fully constructed IceCube detector.

[citation needed] A point source of neutrinos could help explain the mystery of the origin of the highest energy cosmic rays.

These cosmic rays have energies high enough that they cannot be contained by galactic magnetic fields (their gyroradii are larger than the radius of the galaxy), so they are believed to come from extra-galactic sources.

The more energetic an event is, the larger volume IceCube may detect it in; in this sense, IceCube is more similar to Cherenkov telescopes like the Pierre Auger Observatory (an array of Cherenkov detecting tanks) than it is to other neutrino experiments, such as Super-K (with inward-facing PMTs fixing the fiducial volume).

This technique of looking for the decay products of WIMP annihilation is called indirect, as opposed to direct searches which look for dark matter interacting within a contained, instrumented volume.

[23] IceCube can observe neutrino oscillations from atmospheric cosmic ray showers, over a baseline across the Earth.

[25][26][27] As more data is collected and IceCube measurements are refined further, it may be possible to observe the characteristic modification of the oscillation pattern at ~15 GeV that determines the neutrino mass hierarchy.

The described detection strategy, along with its South Pole position, could allow the detector to provide the first robust experimental evidence of extra dimensions predicted in string theory.

[32] The IceCube collaboration has published flux limits for neutrinos from point sources,[33] gamma-ray bursts,[34] and neutralino annihilation in the Sun, with implications for WIMP–proton cross section.

[25][26] The latest measurement with improved detector calibration and data processing from 2023 has resulted in more precise values of the oscillation parameters, determining ∆m232 = (2.41 ± 0.07) × 10−3 eV2 and sin2(θ23) = 0.51 ± 0.05 (normal mass hierarchy).

[27] In July 2018, the IceCube Neutrino Observatory announced that they had traced an extremely-high-energy neutrino that hit their detector in September 2017 back to its point of origin in the blazar TXS 0506 +056 located 5.7 billion light-years away in the direction of the constellation Orion, the results had a statistical significance of 3-3.5σ.

[43][44][45] This was the first time that a neutrino detector had been used to locate an object in space, and indicated that a source of cosmic rays had been identified.

[52][53] In November 2022, IceCube announced strong evidence of a neutrino source emitted by the active galactic nucleus of Messier 77.