Leiden scientists and companies receive 1.37 million euros to develop technology for the Einstein Telescope. This underground telescope will measure gravitational waves and must therefore be extremely sensitive. To that end, the consortium conducts research on the damping of vibrations at temperatures around absolute zero.
I' big news in 2016: for the first time, researchers measured the gravitational waves that Einstein predicted 100 years earlier. And with that, the story only just begins. 'The Einstein Telescope is going to do much more sensitive measurements,' says Bas Hensen, quantum researcher at the Leiden Institute of Physics (LION).
That first detection was caused by two colliding black holes. 'These orbited around each other faster and faster until they finally melted together,' Hensen explains. 'If you convert that data into sound, you hear a short, increasingly higher tone. With the Einstein Telescope, you would hear a low hum much earlier.' This is because it is much more sensitive to low frequencies. This allows you to detect gravitational waves earlier and from more different sources.
Big plans underground
Hearing black holes collide or probing neutron stars? That was unheard of until not so long ago, but the Einstein Telescope is expected to do it all. This telescope will be Europ' most advanced observatory for gravitational waves. It is the successor to the US detector LIGO, which made the first detection in 2015. Distances shrink and stretch almost immeasurably when a gravitational wave passes by. With three corridors, each ten kilometers long, located 250 to 300 meters below the Earth's surface, the Einstein Telescope will be enormous. The South Limburg region hopes to host the observatory along with Germany and Belgium. Construction will take place between 2028 and 2035.
How do you detect such a minuscule effect?
In that low frequency range, you are more affected by vibrations that cause noise in the data. To counteract that, the telescope will be deep underground and the mirrors will hang from springs. 'But tha' not enough,' Hensen says. 'That's why they're also going to cool the mirrors.'
'This project is possible thanks to the vibrant collaboration between science and industry in and around Leiden.'
That brings challenges, says Tjerk Oosterkamp, professor of Experimental Physics at LION. 'The cooling device itself introduces vibrations that we have to compensate for. In Leiden, thanks to our quantum research, we have a lot of knowledge about damping vibrations at extremely cold temperatures.' One of the technologies Oosterkamp is working on involves a floating particle that measures vibrations. 'If you know exactly what the vibrations are like, you can also suppress them better.'
Finally, Hensen is also looking forward to working with Nikhef. 'I think we can learn a lot from each other. Among other things, there will be a shared PhD position. That person can devote themselves completely to this project.' Oosterkamp shares his enthusiasm: 'At Nikhef, they get good vibration damping at room temperature using simulations. I want to apply that at cold temperatures. Ther' still a lot to optimise there.'
Bustling science and industry surrounds Leiden
Local quantum company Onnes Technologies is leading the project and is engaged in integrating such vibration-damping technologies into cryostats. 'In this project, we will market the developed technology so others can also use it and discover new applications. In this way, we ensure that the investments made in research ultimately also grow the Dutch economy,' says CEO Max Kouwenhoven. 'We are very happy to cooperate on a project that can be so gigantically impactful for our understanding of physics and the universe.'
The third Leiden partner is SRON, the Dutch institute for space research. They make complex cryogenic instruments, explains scientist Luciano Gottardi. 'For example, we develop superconducting sensors for space telescopes, which can also be used in the Einstein Telescope and quantum research.' Gottardi received his PhD in Leiden and says he has a deep passion to develop cryogenic detectors for gravitational waves. 'This project is possible thanks to the vibrant collaboration between science and industry in and around Leiden. That makes me incredibly happy.'
Finally, Hensen is also looking forward to working with Nikhef. 'I think we can learn a lot from each other. Among other things, there will be a shared PhD position. That person can devote themselves completely to this project.' Oosterkamp shares his enthusiasm: 'At Nikhef, they get good vibration damping at room temperature using simulations. I want to apply that at cold temperatures. Ther' still a lot to optimise there.'
This project is a collaboration between Leiden University, Onnes Technologies (main applicant), SRON, Nikhef, JPE, Piak Electronic Design, Delft Circuits & Magnetic Innovations.
