Academic staff: Professor J Hough, Dr G P Newton, Dr N A Robertson, Dr H Ward
Research and Related Staff: Mr P W McNamara (part-time), Dr M V Plissi, Dr S Rowan, Dr K D Skeldon, Dr K A Strain, Miss S M Twyford (part-time)
Research Students: Miss M M Casey, Mr D A Clubley, Mr S A McIntosh, Mr D A Palmer, Mr C Torrie
The work of this group, supported by PPARC funding, is at present concentrated on the development of detectors to search for gravitational waves from astrophysical sources. Gravitational waves - waves in the curvature of space-time - are a prediction of General Relativity. In recent years there has been considerable progress towards the detection of these waves. Indirect confirmation of their existence has come from observations of the orbital motion of the binary pulsar PSR 1913+16, for which work Hulse and Taylor were awarded the 1993 Nobel Prize in Physics. This evidence and the recognition of its importance has undoubtedly given a boost to the efforts of physicists worldwide involved in the development and construction of gravitational wave detectors. The group in Glasgow is one of the major research groups in this field.
Gravitational wave detectors: Potential sources of gravitational waves include the collapse of massive stars in supernova explosions and the coalescence of two compact stars such as neutron stars in binary systems. The detection of these waves should give us unique new information about some of the most violent astrophysical processes in the universe, and should allow us to make an unequivocal measurement of the expansion rate of the universe. Detection techniques being developed at Glasgow and elsewhere rely on using laser interferometry to sense the minute changes (of order 10-18 m) induced by a gravitational wave in the relative separation of neighbouring test masses. At present we are working on a prototype detector fitted with ultra-low loss optics, and much of the work of the group is devoted to developing precision interferometric techniques, and to understanding and minimising noise sources such as seismic and thermal noise in delicate optical and mechanical systems. This detector has masses separated by 10 m. However to reach the sensitivity required to start making serious astrophysical observations will require separations of kilometre scale. Development of such long baseline detectors are currently being planned by several groups worldwide, and several projects have already received funding. These include GEO 600, a project in which the Glasgow group, together with colleagues in Cardiff and Germany, are building a 600 m detector at Hannover. Work at the site began in autumn of 1995, and the Glasgow group is deeply involved in several aspects of the design and development of the detector, which should come on line towards the end of the century. Other projects include LIGO in the USA, VIRGO, a joint French/Italian collaboration and TAMA 300 in Japan. The Glasgow group are part of an international collaboration, along with colleagues at JILA, University of Colorado and Stanford University, looking into the design of advanced suspension systems for the LIGO project.
The LISA project: The Glasgow group are also involved in the proposed space-based detector called LISA, which is currently under study by the European Space Agency. This detector would have comparable sensitivity to ground-based detectors, but in a completely different frequency range, and so would be able to explore a different region of the gravitational wave spectrum where signals from highly interesting sources such as massive black holes should be detectable.
Industrial applications: As well as its work on gravitational wave detectors, the Glasgow group was awarded a grant under the PPARC industrial support scheme to develop an instrumental system for making measurements of losses in ultra-high reflectance mirrors, based on our expertise in this area. This work benefited not only us as users of such state-of-the-art mirrors, but also the associated optics company who are producing these mirrors for use in the laser gyroscope industry. Through this work the group has strengthened its ties with two leading high tech UK companies, GEC-Marconi and Omitec. We expect to continue working with these and other companies on the further development and testing of high quality substrates and mirrors. FURTHER INFORMATION:see web pages: http://www.physics.gla.ac.uk/gwg/
or Professor Jim Hough Tel: 0141-330-4706, email: j.hough@physics.gla.ac.uk