use of niobium in a waveguide

https://techxplore.com/news/2023-10-superconducting-niobium-waveguide-high-precision-communications.html

"Nakajima and his collaborators evaluated the use of niobium in a waveguide, a three-dimensional transmission line consisting of a metal tube that guides and confines waves along a specific path, minimizing losses due to radiation and absorption.

This will open up new fields of scientific observation using high-frequency radio waves, such as the observation of very distant galaxies in the early universe, which emit only very weak radio waves, or the monitoring of changes in trace atmospheric constituents in the Earth's upper atmosphere."