ET R&D

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

Abstract

Gravitational waves are the last prediction of general relativity still awaiting direct experimental detection. The efforts in constructing and optimising large interferometers in different locations all over the world in the last two decades have resulted in instruments of extraordinary sensitivity. While the British/German gravitational wave detector GEO 600 is currently taking data, the American LIGO detectors and the Franco/Italian Virgo detector are being upgraded to further increase their sensitivity. Once these upgrades have reached their design sensitivity the theoretical estimates predict the detection of gravitational waves within a few months to a year. Although frequent detections will be possible, the detection of high signal to-noise ratio events, allowing precision gravitational wave astronomy, will be very rare.

The ET-R&D project is aimed at essential R&D tasks in preparation for a technical design of the Einstein Telescope, a 3rd generation, underground gravitational wave detector. It is widely expected that this detector will allow routine gravitational wave astronomy to take place. While the basic design mostly relies on techniques well developed and tested for the advanced detectors, several aspects still require R&D with long lead times. We propose to target the most important of these topics in this ET-R&D project via 5 working groups (WGs).

WG1 will explore how well astrophysical source models and GR itself can be tested with ET, and how much information on the dynamics of the universe can be extracted from the data. WG2 will collect long term seismic data for various candidate sites and develop methods for measuring the seismic motion which directly couples to the test mass motion, with the goal of developing subtraction techniques. WG3 will investigate properties of cryogenic optics essential for lowering detector thermal noise and providing good low frequency performance. The control of various interferometer degrees of freedom and noise correlations in the data of the three different ET detectors will be studied in WG4. WG5 will focus on overall project management.

Glasgow University will play a key role in three of the working groups. In WG1, we will develop methods of parameter estimation for transient signals detected by ET, through application of our existing expertise in gravitational wave data analysis. In WG3 we will develop apparatus for measuring the birefringence of coated silicon samples and apply our expertise in finite element modelling to assist in the interpretation of cryogenic birefringence measurements carried out in collaboration with Hannover and Jena. In WG4 we will carry out studies and simulations of sensing and control issues for ET and carry out detailed modelling of the quantum noise and optical configuration. Collaboration with our UK and European partners and combination of the facilities and expertise available will be essential for the success of this proposal.

Planned Impact

There are already numerous beneficiaries from the existing programs of research in gravitational waves across the UK and Europe, including industry, other academic disciplines, schools, science centres, museums and the general public. The research outlined within this proposal will further strengthen these benefits, by enabling the UK, along with European partners, to maintain international leadership in the development of technologies for future gravitational wave observatories.

Outreach to schools, science centres, museums and the general public is very strong in the field of Gravitational Wave research, driven by interest in viewing the Universe through the medium of gravity - probing black holes, the warping of space-time and the big bang itself. We propose to continue to contribute to on-going outreach efforts, including working with PR companies such as Milde Marketing to disseminate scientific progress to the public.

Publications

10 25 50
 
Description Work begun this grant is ongoing, aiming to carry out key strands of research in preparation for the eventual construction of the Einstein Telescope (ET), a proposed European gravitational wave detector. Studies are ongoing into the optical properties of silicon mirrors, advanced detection techniques and simulations, and methods for analysing the data from ET. In particular, work identifying that silicon mirrors can have significant optical absorption on their surfaces, related to the polishing techniques used, has been carried out and published.
Exploitation Route The findings under this grant will be primarily of interest to the gravitational waves community, and will lay the foundations for the detailed design and eventual construction of the Einstein Telescope (ET) detector. ET is likely to have a huge impact on astronomy, cosmology and astrophysics through carrying out gravitational wave astronomy and measurements of a wide range of sources.

The research carried out into the optical properties of silicon may be of interest to the optics industry and may have some applications in optical sensors.
Sectors Manufacturing, including Industrial Biotechology,Other

 
Description This project aims to support European collaboration to carry out key strands of research targeted at the proposed Einstein Telescope European gravitational wave detector. This project is still underway, and the findings are of great interest to the European gravitational wave community. Our measurements of the optical properties of silicon have led to some interest from an optical polishing company in post-polishing contamination, with some exchange of samples and information to try to understand the effects of polishing on the absorption of silicon.
First Year Of Impact 2014
Sector Manufacturing, including Industrial Biotechology,Other
 
Description AEI Hannover & Jena 
Organisation Friedrich Schiller University Jena (FSU)
Department Institute for Solid State Physics
Country Germany 
Sector Academic/University 
PI Contribution Expertise in the measurement of optical absorption, particularly surface absorption, and the ability to measure the spatial variation of the absorption. Expertise in the measurement of stress birefringence.
Collaborator Contribution Expertise in the measurement of optical absorption and birefringence using optical cavities (Hannover). Expertise in cryogenic measurements of optical absorption (Jena).
Impact Talk at LVC Collaboration meeting, Hannover, September 2013 'Optical absorption studies of silicon' A. Bell et al.
Start Year 2013
 
Description AEI Hannover & Jena 
Organisation Max Planck Society
Department Max Planck Institute for Gravitational Physics
Country Germany 
Sector Public 
PI Contribution Expertise in the measurement of optical absorption, particularly surface absorption, and the ability to measure the spatial variation of the absorption. Expertise in the measurement of stress birefringence.
Collaborator Contribution Expertise in the measurement of optical absorption and birefringence using optical cavities (Hannover). Expertise in cryogenic measurements of optical absorption (Jena).
Impact Talk at LVC Collaboration meeting, Hannover, September 2013 'Optical absorption studies of silicon' A. Bell et al.
Start Year 2013
 
Description ET R&D daya analysis 
Organisation Nice Observatory
Country France 
Sector Public 
PI Contribution Working on Einstein Telescope mock data-analysis challenge, in particular on the supernova waveforms that were injected. We have been following up the injections using Burst parameter estimation methods.
Collaborator Contribution Expertise in data analysis methods for gravitational wave detectors.
Impact Work is ongoing since we found that the code needed to be upgraded to handle the supernova waveforms.
Start Year 2013
 
Description ET R&D interferometry 
Organisation Max Planck Society
Department Max Planck Institute for Gravitational Physics
Country Germany 
Sector Public 
PI Contribution We are providing computer models for various control aspects of the planned Einstein Telescope interferometers.
Collaborator Contribution Expertise in analytical analysis of interferometers and radiation pressure effects and interferometer simulations.
Impact Talk: Christian Graef "ET sensing and Control" at the 5th ET symposium, Hannover Dec 2013
Start Year 2013
 
Description ET R&D interferometry 
Organisation Moscow State University
Country Russian Federation 
Sector Academic/University 
PI Contribution We are providing computer models for various control aspects of the planned Einstein Telescope interferometers.
Collaborator Contribution Expertise in analytical analysis of interferometers and radiation pressure effects and interferometer simulations.
Impact Talk: Christian Graef "ET sensing and Control" at the 5th ET symposium, Hannover Dec 2013
Start Year 2013
 
Description ET R&D interferometry 
Organisation University of Birmingham
Country United Kingdom 
Sector Academic/University 
PI Contribution We are providing computer models for various control aspects of the planned Einstein Telescope interferometers.
Collaborator Contribution Expertise in analytical analysis of interferometers and radiation pressure effects and interferometer simulations.
Impact Talk: Christian Graef "ET sensing and Control" at the 5th ET symposium, Hannover Dec 2013
Start Year 2013
 
Description Icarus 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Science fair associated with production of 'Icarus at the Edge of Time' at Glasgow Concert Hall. Interaction with members of the public, who were enthused about science.

n/a
Year(s) Of Engagement Activity 2010
 
Description Meet the Expert day 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Type Of Presentation Workshop Facilitator
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Many members of the public, particularly children, interacted with researchers at a science fair, generating interest in astronomy and gravitational waves.
Year(s) Of Engagement Activity 2011