NITROGEN AND HELIUM FOR CUTTING-EDGE RESEARCH

Synchrotron light makes it possible to discover the smallest details of matter on the atomic and molecular level and paves the way for scientific advances in biomedicine, material science, archeology, etc. Among the different elements required for operating various synchrotron light devices, the standouts include superconducting magnets, which are cooled with nearly -270°C liquid helium for normal operation.

The helium is partially vaporized while cooling the magnets, but can be re-liquefied by special systems. Up to 80 percent of the gas can be recovered in this way. That reduces both the operating costs and the environmental impact considerably.

Due to the properties of helium, however, the liquefaction of this element poses a special challenge: only after it falls below -233°C does it cool at atmospheric pressure like other gases during expansion. That’s why helium must be pre-cooled to below this temperature before it can be liquefied using the usual cycles from compression and expansion. The pre-cooling is done with cryogenic liquid nitrogen.