AMOS is playing a key role in supporting scientists in the development of new technologies and concepts for the Einstein telescope, the future large European Gravitational Wave detector.
The Einstein telescope will be the next-generation gravitational wave observatory. It will consist of 3 large 10km-long tunnels arranged in a triangular shape. Laser lights will travel those tunnels and be combined in the vertices of the triangle where 6 interferometers will measure the tiny length variations caused by gravitational waves passing through the instrument. The whole infrastructure will be buried between 200 and 300m below the ground surface in order to shield it from potential perturbations generated at the surface. The gravitational wave interferometers are based on a set of suspended mirrors, under vacuum and that reflect the laser light circulating in the tunnels. Those optics shall be cooled to cryogenic temperatures in order to minimize thermal noise. Such interferometer will have to measure the variation of the length of its 10-km arms, with a precision better that one millionth of the diameter of a proton!
To achieve such precision, new technology developments are under way in order to increase the instrument sensitivity. Amongst those, AMOS has been contracted by the University of Liège (ULiege) for the polishing of a large silicon mirror for the E-TEST prototype. This system aims at testing the cooling of a large and heavy mirror at 20K, although the mirror is being continuously hit by a laser, and without inducing unwanted vibrations in the mirror. This mirror is thus very special. Weighting more than 100kg and with a diameter of 45cm for a length of 30cm, it is a thick block of monocrystalline Silicon. AMOS is responsible for the procurement of the silicon slab and for polishing its surface with nanometric precision.
Besides this optical work, AMOS also built a vertical vacuum chamber to test new suspension mechanisms developed at ULiege. This 5.6m-high chamber is now installed at AMOS and will allow scientists and researchers to build and test new suspension mechanisms. Those suspensions will later be used to ensure that the interferometer mirrors stand perfectly still during operations. ULiege has developed a new technology that will allow to make those suspensions far more compact than previous technologies, making the full instrument simpler and more affordable.
“Gravitational-wave astronomy really started in 2015 with the first direct detection of gravitational waves coming from the merging of two black holes. New mergers are being regularly detected with current instruments. The Einstein telescope will however enable the detection of a brand-new range of astronomy phenomena and objects that will this way become accessible to humankind. AMOS is really proud to contribute once more in advancing science with instruments that have never been built before. The skills and know-how of our team members once again contribute to transforming an astronomer’s dream into a reality.” said Xavier Verians, Business Development Director at AMOS.