Trusted CI visits IceCube

Trusted CI staff member Megha Moncy holding one of the many hard drives shipped back from the South Pole containing neutrino research data

 

"Have you ever held $300,000 in your hands?" At least that's the way Steve Barnet put it as he allowed us to hold one of the hard drives that had been shipped back from the main IceCube Neutrino detector in Antarctica. Steve is the IT manager for the IceCube Neutrino Detector, which is an NSF Major Facility allowing scientists from around the globe to study neutrinos. Steve estimates that each drive shipped back has around $300,000 worth of scientific data on it, based on the cost of collecting the data.

In June 2025, members of the Trusted CI team took the opportunity to tour the IceCube Neutrino Detector data center and development facility at the University of Wisconsin - Madison. The team learned about the custom designed sensors and equipment that make up the 1 cubic kilometer detector buried under 1.5 km of ice at the South Pole.
Because the detector produces about 1TB per day of data, and satellite communication to the South Pole is limited, it's still far more efficient to ship hard drives back to the lab after a season of data collection at the detector is finished. However, because the data is so valuable, they write the data to at least two separate arrays of hard drives and ship them on separate logistical channels in case of catastrophe during shipment.

Steve Barnet (right), giving a tour of the IceCube development facility.

The IceCube data center in Madison also simulates the layout of the facility in Antarctica so that they can better plan any changes made to the infrastructure and to be sure that equipment that is shipped down to the South Pole facility will fit around corners, be compatible with installed equipment, and have enough power.

The IceCube sensors, which are called "digital optical modules", are about the size of a basketball but surprisingly weigh more than a bowling ball. Most of the weight is owed to the thick glass in each sensor pod that shields the sensitive electronics and photomultipliers from the 1 to 2 kilometers of ice that sit above them. The unique sensors were designed and built by several institutions within the international IceCube Collaboration to withstand the extreme environment of Antarctica. 

Trusted CI staff member Mark Krenz holding one of the digital optical modules.

Neutrinos are a fundamental particle generated by the universe's most extreme events such as supernovae and black holes. They travel in straight lines from their origin through the universe, passing through ordinary matter. As neutrinos pass through the Earth from all directions, including through the core of the planet, neutrinos whose path takes them through the south pole IceCube detector pass through the large cubic kilometer of ice making up the array. Most of them pass right through the detector without any interaction, but occasionally they hit an atom in the ice and generate secondary charged particles which travel through the ice faster than light travels through ice. This produces Cherenkov radiation, which creates a blue flash of light. This blue light phenomenon of Cherenkov radiation is what the photomultipliers actually detect.

 

IceCube's testing and development array of sensors.

The facility also has a test array of sensors that are not encased in glass and stacked closely together that allow IceCube staff to run tests and diagnostics on the electronics before performing the same operations on the production sensor array. This reduces the chance of an incident that damages the entire array, "which would be bad", according to Steve (he likes understatement). Availability is a crucial security requirement for the IceCube array, and one of the threats against the sensors continuing to function is the extreme cold damaging the electronics inside. If the array loses electricity, it would only be a matter of a day or so before large parts of the array would become unrecoverable. Thus, it is important that a generator powering the array in Antarctica run continuously uninterrupted over the lifetime of the experiment. Trusted CI benefits from visiting the IceCube facility by seeing the equipment and better understanding the processes used to program, deploy, and protect the equipment from a variety of security threats.