Ripples in the fabric of space-time
Gravitational waves are ripples in the curvature of space-time which propagate as a wave, travelling outwards from the source. Detecting these waves helps to confirm the explanation of gravity as predicted by Einstein’s theory of relativity. These waves are detected using interferometers on the ground and in space.
It is essential that the observatories housing the interferometers are perfectly clean and extremely stable; the whole interferometer must remain as optically perfect as possible. Any residual gas would affect the measurement, so the light beam must operate under an ultra-high vacuum.
Edwards' XDS scroll pumps have been used for over 10 years by Virgo in Italy. The Virgo detector for gravitational waves has two 3 km long tubes, each 1.2 m in diameter, which are the largest ultra-high vacuum vessels in Europe, and the second largest in the world. With their innovative design and robustness, the XDS dry scroll pumps have been used for various experimental set-ups, including pre-evacuation and baking out of large chambers.
For more than 20 years the two LIGO observatories in the USA, which were the first gravitational wave observatory to detect gravitational waves, have relied on Edwards oil free dry pumps and STP magnetically levitated turbomolecular pumps.