21 March 2016

New vacuum pumps for hybrid magnet

Old vacuum pumps are removed from the lab to make new for state-of-the-art replacements. Old vacuum pumps are removed from the lab to make new for state-of-the-art replacements. Stephen Bilenky

This week at the lab, we retired a 1990 Toyota and are parking a 2016 Mercedes in its spot.

That's the metaphor offered by Bryon Dalton, head of operations for the lab's DC Field Facility, for a big upgrade of the lab's world-record 45 tesla hybrid magnet: a new set of 3,500-pound vacuum pumps.

Good-bye roll-down windows and Bush Sr.-era fuel economy. Hello turn-by-turn navigation, Bluetooth wireless data link and 10-way power driver seat.

The $260,000 German-made vacuum pumps will improve reliability and performance, generate systems diagnostics, and allow staff to run the pumps remotely. "You're going to have a better feel for what's going on and better control over it," said Dalton.

The pumps play a critical role in the operation of the hybrid, which pairs a resistive magnet with a superconducting magnet of niobium-tin and niobium titanium that requires temperatures near absolute zero. Helium liquefied on site has a temperature of 4.7 Kelvin, making Plutonian weather seem tropical by comparison. By dropping that liquid helium to below atmospheric pressure, the vacuum pumps, used with a special cooling apparatus called a Joules-Thompson refrigerator, gets it down to 1.6 Kelvin. This turns it into a zero-viscosity "superfluid" and maximizes the hybrid's efficiency.


Photo by Stephen Bilenky, text by Kristen Coyne.

Last modified on 21 March 2016