Capturing a Piece of the Universe

September 25, 2018

AntarcticaLocated on the vast ice-covered landscape of Antarctica, between mountains covered in snow, and far from any living community, you'll find small detectors set to sense neutrinos—particles created by cosmic rays coming from space.

Assistant Professor of Physics Jordan Hanson is part of a team of researchers from all over the world who are responsible for creating and setting those detectors. 

The team's goal is to capture neutrinos in their most natural state, which travel with much higher energies than we can currently give sub-atomic particles on Earth. 
"At higher levels, the energy changes the way things interact on a subatomic level," said Hanson. "When you grab a cosmic ray from space, you're actually peering into the fundamental laws that govern the universe."
The detectors were carefully set in Antarctica by Hanson and his colleagues to sense when a neutrino makes impact with the ice starting in 2009. 
Neutrinos, unlike protons and electrons, carry no electric charge, have almost no mass, and rarely interact with matter. They obey different rules of quantum mechanics and are viewed as "wild" particles in their natural state. Placing the detectors in Antarctica gives Hanson's team the ability to monitor a vast area of ice, which can be observed with relatively few detectors. When a neutrino makes impact, the ice produces radio pulses that can be picked the detector over distances of several kilometers. 
The group’s research shows that the radio waves from neutrinos can propagate horizontally, contrary to the conventional wisdom that the changing index of refractions pulls the waves down toward the Earth. “Normally, light experiencing a changing index of refraction travels in a curved path, like the light that leads to the effect of a mirage,” said Hanson. “However, special cases apparently exist for radio waves in ice, where the waves were observed to travel for multiple kilometers with no bending. This potentially increases the probability that such a wave will hit one of the group's detectors.”

The results were published this summer in the Journal of Cosmology and Astroparticle Physics.
Hanson is continuing his research and working with the group to create a different type of detector that will cover more kilometers of ice, increasing the chances of sensing neutrino activity. He plans to return to Antarctica and set the new detectors in a different location and hopes to take group of Whittier students with him. To read more about their research, visit the group’s website.