23 May 2016

Science on ice -- and at a snail's pace

A look into the room above the 16.5 tesla superconducting magnet in bay 3 of the High B/T Facility. A look into the room above the 16.5 tesla superconducting magnet in bay 3 of the High B/T Facility. Dave Barfield.

This week at the lab, a Canadian scientist working in Gainesville, Florida, is trying to detect something never before seen in experiments that require temperatures so frigid not even a Mountie could endure them.

And because cold makes everything from parka-puffy children to atoms slow down, he is in the Sunshine State for the long haul. While experiments at the MagLab's six other facilities typically last a week, scientists using the instruments at the MagLab's High B/T Facility on the University of Florida campus usually hunker down for several months.

Simon Bilodeau.Simon Bilodeau is a few weeks into a 3-month series of experiments at the High B/T Facility.

The "B" and "T" in "High B/T" stand for magnetic field and temperature, respectively. Scientists who use these unique systems are looking at samples at very high fields and at temperatures so low they hover just above absolute zero. It takes weeks to get the magnet that cold and for the samples inside it to adjust.

"At these extremely low temperatures, there's very little motion left, very few degrees of freedom," explained High B/T Facility Director Neil Sullivan. "So you can wait a long, long time to get to the state of thermal equilibrium."

Simon Bilodeau, a graduate student in the group of Guillaume Gervais at McGill University in Montreal, is a few weeks into a three-month stint in Gainesville using a 16.5 tesla superconducting magnet. The experiments require constantly adjusting the magnetic field for new data.

"You might get two measurements done in the course of a day at one temperature, one field," said Sullivan. "Then you move on to the next one — move the temperature, move the field, wait for equilibrium again, prove you've got equilibrium, measure the temperature, then go ahead and take the measurement. You might get two points on a graph in a day. So if the graph has, say, 100 points, there's 50 days."

While the details on this experiment are being kept under wraps for the time being, Bilodeau is looking for a new effect that has been predicted but so far not proven, said Sullivan. It's a very difficult but exciting "high-risk" experiment: It could end with a big publication or be more or less a bust.

"If we aren't occasionally taking risks and doing experiments that look for new effects," said Sullivan, "even where we might fail, then, maybe, we aren't doing the right thing."


Main image by Dave Barfield / Secondary image courtesy of Neil Sullivan / Text by Kristen Coyne.

Last modified on 23 May 2016