THE UNITED KINGDOM INFRARED TELESCOPE
ANNUAL REPORT
1995 AND 1996

6. UKIRT Upgrades

6.6. Primary Mirror Cooling System

The primary mirror cooling system was designed in 1995 for installation in two stages. The first of these was completed in 1996 and provides a capability to force ventilate the mirror with air through 15 radial nozzles mounted at its inner periphery. The second stage involves the installation of the 5 kW cooling/heating unit, its connection to the ventilation system by suitable ductwork, and development and installation of a control system.

The ventilation system will not enter general use until the cooling system is also operational, as the power dissipation of the axially-mounted low-vibration fan warms the air by 1.5 C and until it can be cooled back to ambient this would degrade, rather than improve, the seeing. The cooling/heating unit on the mirror cell, the cooler unit in the plant room and the pipework for the ethylene glycol coolant are all in place, but completion of the system awaits both mechanical and electronic engineering effort for completion of ductwork and controls, respectively.