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WIYN Nears Completion! (1Dec93) (from NOAO Highlights!, NOAO Newsletter No. 36, 1 December 1993) Installation of the 3.5 WIYN telescope continues on Kitt Peak. The telescope mount is in place and work continues on the control system and optics. The primary mirror will travel to the mountain in January and the delicate task of installing optics will begin. This effort is expected to take two months followed by the final integration of the control system. In the current schedule, commissioning starts in April once all telescope systems are in place. The first tasks are tuning of the drives and the adjustment and evaluation of the optics and their supports. Preparations for this phase are well underway. A site manager, David Sawyer has been hired and the operations staff is being identified. During the last quarter, the WIYN primary mirror group prepared the mirror cell and support systems for mating of the mirror to the cell in preparation for testing prior to delivery of the mirror to the observatory in January. After some delays, all parts of the new axial support mechanisms were delivered and the units assembled. The 66 axial units and the modified 24 lateral supports were mounted to the cell and connected with stainless steel tubing to form the hydraulically connected lateral support system and the 3 axial support zones. In addition, the control electronics were updated and additional diagnostic software written. New LVDT units which sense the mirror position in the cell were fabricated and mounted near the outer edge of the mirror to provide better access and greater sensitivity. Portions of the cell were repainted, and other cleanup work was done to ready the system for testing which is expected to begin in mid-October. Contraves is polishing the 1.2-m secondary mirror for WIYN. The surface quality is steadily converging on its final figure. The mirror is being tested interferometrically over its full aperture using NOAO's 100" test sphere and a null lens. The polishing is behind schedule and a concerted effort is underway to complete the mirror in time for a February installation in the telescope. In the meantime, the secondary mirror cell is being fabricated at NOAO and is expected to be finished prior to delivery of the mirror. Kodak completed the tertiary mirror to WIYN's specifications. It is now back at NOAO waiting for completion of its cell. The tertiary mirror rotator and tilt assembly that allows the telescope beam to be directed to any one of three instrument ports was delivered to NOAO in September. It was mounted on the primary mirror cell, checked for fit, and is currently being readied for final installation in the telescope. [Figure not included] Two 0.5-m diameter fused silica blanks were ordered for the 1 degree wide-field corrector. The first blank was received in September and the second blank is expected in early November. The lenses for the corrector are being polished by Rayleigh Optical in Tucson. The detailed design of the Instrument Adapter ("guider box") is progressing with fabrication to start next quarter. Orders are being placed for long lead-time items including guide cameras and a CCD for the wavefront sensor. Last quarter's activities at the Observatory centered around cabling and preparations for the control system. Cable drapes and wind-ups were installed on the telescope and additional conduits and trays were provided in the enclosure. Work also continued on building systems. The control system status displays and network hardware were installed by the University of Wisconsin Controls Group. The remainder of the controls will be delivered through the rest of 1993. Using the software being supplied by UW, the telescope will be operated with commands entered from the keyboard. A graphical interface will be developed during the coming year. Matt Johns, Caty Pilachowski, Richard Wolff
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