MEL Seminar / IEEE Springfield Chapter Technical Meeting
Monday April 6, 1998

THE MILLIMETER ARRAY RADIO TELESCOPE:
NEW TECHNOLOGY IN RADIO ASTRONOMY

Larry R. D'Addario
National Radio Astronomy Observatory
2015 Ivy Road, Charlottesville, VA 22903, USA
telephone +1/804/296-0245
fax +1/804/296-0324

ABSTRACT

The Millimeter Array (MMA) is a large, Fourier-synthesis telescope for the frequency range 30 to 950 GHz. It is now under development by the National Radio Astronomy Observatory, funded by NSF, with construction scheduled to begin in 2001 and finish in 2007. The present plan calls for an array of 36 10-m dishes distributed on a circle of up to 10 km diameter. Enhancement by consolidation with similar projects proposed in Europe and Japan is under discussion. Deployment at a high altitude site is essential for sufficient atmospheric transparency at sub-mm wavelengths; the favored site is in the Atacama desert of northern Chile, at an elevation of about 5000 m.

This talk will emphasize a wide variety of technical innovations being developed for the MMA. These include expected advances in superconducting front ends (SIS and HEB mixers with integrated structures allowing image separation and large instantaneous bandwidth); much more efficient cryogenic refrigeration; mm and sum-mm signal generation by mixing IR lasers; and clever digital architectures for correlation of multi-GHz bandwidths. Various people at the NRAO and elsewhere are involved in these developments.

BIOGRAPHY

Larry D'Addario received his SB degree from MIT, and his MS and PhD degrees from Stanford University, all in Electrical Engineering. He has been with the National Radio Astronomy Observatory since 1974, during which time he contributed to the development of the VLA and VLBA radio telescopes, designed low-noise millimeter wave components including superconducting mixers, and recently has been the chief engineer and project manager for an earth station supporting orbiting VLBI with Japanese and Russian satellites. He is presently a member of the team developing low-noise receivers for the Millimeter Array.