THE LOVELL TELESCOPE - FORWARD INTO THE 21st CENTURY

Application for Funding
1998 Joint Infrastructure Fund

University of Manchester, Nuffield Radio Astronomy Laboratories, Jodrell Bank,
Lower Withington, Macclesfield, Cheshire SK11 9DL, UK

1. Important Entries from JIF Application - Part 1 of Application
2. Summary of Scientific Rationale - Part 2(ii) of Application
3. Other Information - Part 4(v) of Application (Added Value)
4. Research Strategy - Part 5 of Application
5. Scientific Rationale for the New Equipment
6. References
7. Justification for Funds Requested

SUMMARY OF THE PROPOSAL - PART 2(i) OF APPLICATION

The University of Manchester's giant 76-metre Lovell radio telescope (LT) at Jodrell Bank is probably the most famous working scientific instrument in the land and is widely regarded by the public as an icon of the very best achievements of British science and technology.

For over 40 years, the LT has been at the forefront of astronomical research on the international scene because of its great flexibility and large collecting area. It is still the second largest fully-steerable radio telescope in the world (third, when the 101-metre American Green Bank Telescope (GBT), currently under construction, is completed). Equipped with state-of-the-art receiver systems, embodying the latest developments in low noise amplifier technology, the telescope is now 30 times more sensitive than when it was first built. In recent years it has played a leading role in many studies, including the detection and study of new populations of pulsars and the discovery of the first gravitational lens. Unique among the world's large steerable reflectors, the LT plays a vital role in a real- time high-resolution radio-imaging array - the MERLIN National Facility. The LT's collecting area more than doubles the sensitivity of MERLIN and enables observations of faint sources to be carried out which would otherwise be impracticable. The LT is also a key element in Very Long Baseline Interferometers (VLBI) particularly the European VLBI Network of telescopes (the EVN). VLBI provides the highest resolution of any astronomical technique - up to 1000 times that of the Hubble Space Telescope. The LT also attracts great public interest through its participation in the most sensitive search ever for signals from extra-terrestrial intelligence. An illustrated overview of the work of the Jodrell Bank Observatory can be seen on the World-Wide-Web at http://www.jb.man.ac.uk.

A serious restriction to the range of research currently carried out by the LT is its present maximum operating frequency of 1.7 GHz (18 cm wavelength). In particular, it is not able to work usefully at the international standard frequency of 5 GHz (6 cm wavelength) which is used by MERLIN and the EVN for over a third of their time. We therefore request funding for a cost-effective upgrade to the LT which will expand the operational frequency range by a factor of about four and increase the sensitivity at 5 GHz by a factor of five. The upgrade will extend the life of the LT, taking it into a second half-century of research with as much promise and potential as when it was first built.

The upgraded LT will retain the full versatility of the present telescope and allow a wide range of new science to be carried out. As a stand-alone instrument it is expected that the upgraded LT will be used to discover new distant pulsars hidden by the interstellar medium, make a census of star-formation sites in the Galaxy through the observation of the spectral lines of formaldehyde, excited hydroxyl (OH) and methanol and conduct a very deep survey for faint extra-galactic radio sources and galactic radio stars. Coupled with forseeable improvements in receiver technology, the enhancement will increase the sensitivity of the MERLIN National Facility by a factor of about three at 5 GHz and will open up exciting new areas of astrophysical study at a resolution which exceeds that of the Hubble Space Telescope (HST) and is matched to that of the planned next generation of telescopes in other wavebands. The contribution of the LT to European and global VLBI will also be significantly enhanced, with the upgraded telescope able to play a significant role in the expansion of VLBI activities into space. Major advances can be expected in the investigation of objects ranging from nearby stars in the Milky Way to the most distant galaxies and quasars. However, as in the past, the most important and exciting discoveries by the telescope will be those which are totally unpredictable.

Recent structural surveys of the telescope have given assurance that, with the exception of a small number of areas, the basic structure of the telescope and its foundations are in good condition. The upgrade package has four main elements:

New reflecting surface

The present corroded surface panels will be replaced by galvanised steel plate. Attachment will be with self tapping screws to avoid thermal distortions of the type induced in the present surface by spot welding. Corroded panel adjusters will be replaced.

Surface adjustment

Using modern holographic profiling techniques, the new surface will be set to optimise the efficiency of the telescope for operation at frequencies above 5 GHz.

New pointing control system

The present drive and control system will be replaced by state-of-the-art technology to increase the precision of the positional control. This will involve independent control of individual drive motors.

Refurbishment of the track and foundations.

Remedial work on the surface layer of the foundations will be carried out as recommended by specialists to prevent water ingress. The outer azimuthal track will be relaid to the current British standard.

The majority of the work would be carried out in the summers of 2000 and 2001 at a cost of 2.1M, excluding contingency. This is a fraction of the cost (at least 30M) of building a new telescope of this size having the proposed performance and about equal to the cost of constructing a new 2-m optical telescope, of which more than 100 already exist world-wide.