The next-generation gravitational-wave observatory network

Lead Research Organisation: Cardiff University
Department Name: School of Physics and Astronomy


Our preliminary activity proposal aims to enable the UK to co-develop the Conceptual Design of the next generation of gravitational-wave observatory infrastructure. While the current 'Advanced' generation of GW observatories continue to deliver science from GW signals coming from our local Universe, new, 'next-generation' infrastructure is needed to realise the full transformative potential of GW astronomy.

The next-generation GW network, consisting of new US 'Cosmic Explorer' (CE) and European 'Einstein Telescope' (ET) observatory nodes, will provide guaranteed discoveries in astrophysics, cosmology, and fundamental physics. CE and ET are now entering a design phase, including delivery of conceptual designs to go a factor of 10 or more beyond the sensitivity of current GW detectors. This places ultra-stringent requirements on isolating the mirrors from all sources of external disturbance and requires precision measurement technology which pushes the state-of-the-art across numerous fields, including mirror suspension design, coating development and control systems. Further, on the data collection and analysis front, there is a requirement to develop theoretical waveform models whose performance is robust in the sensitivity regime of next-generation detectors, where hundreds of thousands of signals per year are expected. Existing processing tools and digital infrastructure do not scale up to the analysis challenge presented by the anticipated detection rates, thus a paradigm shift in software and hardware designs will be required.

By building on UK expertise in these areas, conceptual designs for relevant subsystems and subsystem components of the next-generation observatories will be developed. More precisely, we will target delivery of conceptual designs that are aligned with the sensitivity improvements (a factor of 10) and consequent increase in the volume of the Universe probed (a factor of ~1000) discussed earlier. As well as a transformative increase in rate, this will lead to observation of loud sources enabling precision astronomy and astrophysics of compact object sources, enabling a global vision of mapping GW sources out to the edge of the Universe, revealing processes in the development of our Cosmos obtainable by no other means.

The UK contribution to next-generation GW infrastructures is fully integrated within the CE and ET projects. We describe our project in terms of seven Work Packages (WP0-WP6) introduced here: WP0: management; WP1 Suspensions: to develop a conceptual design for the suspensions systems for the heavier masses in next-generation observatories that are essential for sensitivity improvement; WP2: mirror coatings: to develop characterisation and optimisation strategies for development of coatings of greater than 600mm diameter; WP3 inertial control: development of aspects of suspension/active seismic sensing and control; WP4 interferometer sensing and controls: conceptual design of a robust interferometer sensing and control scheme for interferometers of extended baselines; WP5: Science traceability matrix: determination of the impact of instrument design on target science deliverables; WP6: Digital infrastructure: design/prototyping of digital infrastructures for real-time operation in the signal rich era.


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