Smithsonian Astrophysical Observatory, 60 Garden Street, M/S 22, Cambridge, MA 02138-1516

99 -- GLASS BLANKS FOR BINOSPEC COLLIMATOR SOL RFO-BF4433 DUE 100799 POC POC: EJ Dotts, 617-496-7562, 617-496-7978 (fax), edotts@cfa.harvard.edu/Contracting Officer: Priscilla O. Waltner, 617-495-7401, pwaltner@cfa.harvard.edu The Smithsonian Astrophysical Observatory (SAO) intends to award on a sole source basis a contract to Ohara Corporation, 50 Columbia Road, Somerville, NJ 08876-3519, per justification pursuant to FAR 13.106, Only One Responsible Source and No Other Supplies or Services Will Satisfy Agency Requirements. No other source is known for glass blanks that meet our design requirements for specialized glasses that are used in the Binospec Spectrograph Collimator. SAO has expended several years optically designing the Binospec Spectrograph System and athermalizing the design so that it maintains performance over a wide temperature range. The key glass properties including the detailed behavior of the refractive index with wavelength and temperature and coefficient of thermal expansion must be explicitly taken into account for the exact glass choices in the design of this Spectrograph. SAO's design was based on the Ohara "iline" glasses, which are a set of very high purity glasses with very good transmission in the blue and ultraviolet portion of the spectrum. They have demonstrated excellent past performance as they have provided us the glass for the primary mirror of the converted MMT and the telescope where the Binospec will be used. Purchasing glass blanks from any other manufacturer would result in changes to the critical glass properties that would require a very lengthy design and analysis process, which would significantly increase the costs of this acquisition. SAO intends to purchase a total of 21 optical glass blanks. Three each of the following optical glass blanks, all measurements in mm center thickness and diameter, respectively: 1) BAL15Y 92, 321; 2) S-FSL5Y 108, 317; 3) PBM2Y 92, 306; 4) PBL6Y 116, 288; 5) PBL6Y 80, 218; 6) BAL35Y 115, 240; and 7) BSM51Y 45, 291. These blanks are to have the internal transmission, refractive indices, mechanical properties, and thermal properties described in the Ohara Corporation's July 1998 i-Line Glass Catalog. In addition, the following requirements apply: 1) Striae grade A, per Mil-G-174B; 2) Refractive index homogeneity +/- 2 x 10 (-6); 3) Precision anneal 6. Maximum birefringence 6 nm/cm; 4) Bubble group 1; 5) Homogeneity, striae, birefringence, and bubble qualities guaranteed over a central aperture that is 95% of the blank dimension; 6) Blank dimension tolerances of +3, -0 mm; 7) Each set of blanks to come from one melt/anneal cycle; and 8) Coefficient of thermal expansion within +/- 3 x 10 (-7) of Catalog values. The desired delivery date is 5 months ARO. This acquisition will be accomplished using commercial and simplified acquisition procedures in accordance with the Federal Acquisition Regulation Parts 12 and 13.5. No solicitation package will be issued. Information received will normally be considered solely for the purpose of determining whether to conduct a competitive procurement. A determination by SAO to not compete this effort on a full and open competitive basis, based upon responses to this notice, is solely within the discretion of SAO. Questions orcomments may be directed to EJ Dotts at 617-496-7562, or by e-mail at edotts@cfa.harvard.edu. Posted 09/29/99 (I-SN386277). (0272)

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