The perils of upgrading a particle detector buried in Antarctic ice

To get a perspective on this one-of-a-kind detector, we talked with John Kelley, IceCube's detector operations manager and self-proclaimed Ars reader.While neutrinos only rarely interact with other matter—it's estimated that you need about a lightyear of lead to stop them—there are a lot of neutrinos around, and IceCube monitors a lot of matter. With careful timing information on when and where flashes of light were detected, it's possible to work backward to determine if they came from a single source and, if so, figure out that source's path through the ice."IceCube's main mission was to find high-energy astrophysical neutrinos," Kelley told Ars. If they're within the right energy range, their collision with Earth's ice will be picked up by the photodetectors of IceCube.(Kelley said that there's a test detector set up to look into the prospects of picking up even higher energy neutrinos using radio radiation, but there's not enough ice instrumented yet to have picked up any.)The upgrade, Kelley said, is to focus on lower energy neutrinos. While Kelley said high-energy neutrinos can arise "anywhere you have high energy particle acceleration," the list of possible sources is long: "shock waves, supernova remnant shells, flares, active galactic nucleus jets—any of those could potentially produce cosmic rays and neutrinos."We're still trying to figure out which of these is producing most of the neutrinos we see, but IceCube has already determined that the optical signals associated with gamma ray bursts aren't accompanied by neutrinos, suggesting they're not a major source.And plans are underway for a greatly expanded IceCube, far beyond the upgrade that's in the works. Referring to IceCube Gen 2, Kelley said, "it's where we go big." Ten times the size, more sensitive optics, and multiple sensors will make sure we get more out of every neutrino that interacts with the ice.You must login or create an account to comment.Join the Ars Orbital Transmission mailing list to get weekly updates delivered to your inbox.