Proposal for UK Involvement in the Operation of Advanced LIGO

Lead Research Organisation: University of Sheffield
Department Name: Physics and Astronomy

Abstract

Within the next five years, and before the end of the period covered by this proposal, Advanced LIGO (aLIGO) is confidently expected to detect gravitational waves and hence to open a new era in astronomy. In this proposal we request support for essential infrastructure and travel costs required to ensure that the UK maintains its place among the leaders in the field and partnership within the project.
Through the design and construction project "Advanced LIGO UK", the UK has succeeded in making unique and fundamental contributions to major aspects of the aLIGO gravitational wave detectors in the US, primarily by transfer of silica suspension technology originally developed for GEO600. The resulting suspensions are absolutely central in enabling aLIGO to meet its sensitivity target. During the first phase of operations, the UK supplied equipment has been installed and integrated into two aLIGO detectors. As a direct result, UK groups are in a position to exploit the rich science data that will be produced by these detectors and their observing partners during the current decade. We propose to maximise the UK position by providing the support and infrastructure necessary for full involvement in the operation of the aLIGO detectors and therefore to remain active partners in the user-community group, the LIGO Scientific Collaboration (LSC), through which data rights are earned and distributed.
Of similar importance is the need to ensure that UK-delivered equipment and facilities for the aLIGO detectors are fully exploited to maximise the potential scientific output. This is true both in terms of their implementation within aLIGO, and later when it is planned that aLIGO will be further upgraded.
The UK membership of the LSC is considerable - currently 12% by authorship. The ALUK project and exchange of data from GEO600 have allowed us to leverage data access and science return for a relatively small investment in the aLIGO hardware. As set out in our Memorandum of Understanding (MOU) with LIGO, we have been given top-level project management roles, up to and including a seat on the project Oversight Committee for an STFC representative. It is essential that we maintain involvement at the highest level as set out in detail in this proposal. We therefore request continuation of travel support for observing duties, resources to allow us to provide technical support during detector commissioning and operations, and computer infrastructure support to provide a solid basis for exploitation of aLIGO science data within the UK.
At the LIGO sites, first tests of the completed detectors are underway, and in November 2014, just a few months after first operation, the LLO detector achieved sensitivity to coalescing binary neutron stars at over 50 megaparsec (Mpc) distance - well on target for initial science runs to start in 2015.
We request funding for the period 01/01/2016 to 31/12/2019.

Planned Impact

The immediate beneficiaries include the UK astronomy community - extending far beyond just the applicant groups, who will gain access to LIGO data at the time when the first gravitational wave signals are most likely to be seen. In the longer term the research will radically alter our understanding of the Universe, including information on the nature of neutron stars and black holes, and through opportunities for precision cosmology. This will benefit the widest astronomy/astrophysics community, internationally.
As cosmology and astrophysics are always forefront areas for public outreach, there will be considerable impact resulting from the discovery of gravitational waves and the burgeoning science that will inevitably result. To have a major focus for this new science in the UK should help revitalise public interest at a time when economic pressures could potentially fight against the growth of science in our community. There is no doubt that a discovery of gravitational waves would galvanise public interest at all levels from school pupils up. An improved understanding of cosmology and compact-object astrophysics, of the most impressive and even violent nature, is bound to catch the public imagination, and produce demand for creative works such as television programmes. A concrete example of direct benefit of Advanced LIGO UK to the popular culture exists in the Science Museum, London, where pre-prototype test mass and the metal structural components of an Advanced LIGO test-mass suspension, both made available by the collaboration, are on display.
The earlier Advanced LIGO UK construction project brought direct benefit to several areas of UK industry both through the placement of over £3M of contracts, but also by pushing manufacturing techniques to reach higher standards of quality and precision required for our work. Examples include: optics, precision mechanics and electronics. In some cases these companies have subsequently been able to market the esulting technology, nationally and internationally.
The operations proposal will lead to further developments in the areas of grid computing, particularly in the field of authentication and access control - an area where the UK already leads.
In summary there is a wide range of potential impact. The majority of these should start to be realised well within the duration of the project (it is more than likely that a discovery will be made around 2015, if not before). By the close of the project gravitational wave science should be becoming mature, and the consequences for both science and its public understanding should have attained major proportions.

Publications


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Title APL 
Description APL is a class of phase locked loop developed in other research which in this grant was applied in particular to the problem of tracking parametric instabilities in gravitational wave detectors. As a result of applying APL to this problem, enhanced methods of using APL in the case where multiple oscillations at almost degenerate frequencies were developed. These methods in turn may be applied to other problems where multiple frequencies are present simultaneously in the future. In particular, these enhancements may be applicable to the problem of control of induction motors, where the currents in drive coils contain many frequency components. 
Type Of Material Improvements to research infrastructure 
Year Produced 2016 
Provided To Others? Yes  
Impact APL is being used by the Glasgow group to characterise violin modes of suspension wires for Gravitational Wave interferometers. It is also being used for various dynamic line tracking applications by researchers at the LIGO laboratories. It is one of several methods in place for the suppression of parametric instabilities at LIGO.