The Infrared Flux Collector, as it was originally called, was proposed by Prof. Jim Ring of Imperial College, London and Gordon Carpenter of the Royal Observatory, Edinburgh. It was built between 1975 and 1978. It is a classical Cassegrain telescope with a primary mirror which is about half as thick as those of conventional telescopes of its era. The design is derived from that of the 1.5m IR Flux Collector (now the Carlos Sanchez Telescope) in Tenerife, and was originally conceived as an inexpensive “light bucket” with very relaxed specifications.
The mechanical structure of UKIRT was designed and built by Dunford Hadfields of Sheffield, UK, and the optics (originally providing f/9 Cassegrain and f/19 coude foci) were manufactured by the now-defunct firm of Grubb Parsons & Co. of Newcastle-upon-Tyne, UK, who pioneered the figuring of large thin mirrors in the process.
The telescope was officially opened in October 1979. Since then it has been steadily improved; by the early ’80s it was performing several times better than its specifications required. After a programme of upgrades carried out between 1990 and 1998 it is currently delivering what is believed to be the best imaging performance of any ground-based telescope. Thanks to this and to a state-of-the-art instrument suite UKIRT is currently one of the most scientifically productive telescopes in the world, producing over 80 scientific papers per year.
UKIRT currently operates at f/36.4; details of its optical system are listed elsewhere.