Kitt Peak 60-cm vacuum telescope.

Described is a major new tool for solar research, conceived and built during a time of budget restraint.The observation of magnetic and velocity (circulation) field structure on a synoptic basis and with diffractionlimited resolution is the aim. New optical features include the use of oversize mirrors and windows(to avoid thermal edge effects) and the placement of the coelostat feed outside the vacuum, mainly foreconomy. The site selected has prevailing winds that clear thermals from these mirrors. Test data in theform of the system MTF and optical transmission, together with examples of full disk magnetograms andphotoheliograms, show present performance capability. Measured MTF indicates a response of 0.2 at 1sec of arc (whereas diffraction-limited response would be ~0.8). System transmission, including the accompanying spectrograph, is only 2-3% (lambdaO.44-1.1 microm). Thus, both the optical quality and efficiency aresubject to improvement.