(CLOSED) Request for Quotation RFQ131001 to Supply the Primary Mirror Blank for the First of Four PanSTARRS Telescopes
7 May 2004
Requirements and Specifications
Introduction
The PanSTARRS project calls for deployment of four identical 1.8 meter telescopes.
This Request for Quotation (RFQ) asks for a price and delivery for a single mirror blank generated to net dimensions as specified in the accompanying text and drawing (DRAWING NO. PSTD-020-001-01). PanSTARRS plans to buy a total of at least four identical mirror blanks (as specified herein) over the next two to three years.
PanSTARRS also requests an alternate bid price per blank for a scenario in which all blanks are ordered in a single purchase agreement. Informal discussions with glass vendors have given us reason to believe that such a scenario would allow a vendor to include all blanks in its manufacturing schedule initially and could thus reduce the overall cost of the blanks as well as securing deliveries on a more predictable schedule.
Please offer your most aggressive anticipated delivery schedule but not so aggressive that it adds extra costs for special efforts. We need the first blank as soon as possible and have funding in place now. Funding for the remaining three blanks becomes available first in April 2005. Please make clear in your offer any special contingency terms that you would require in order to deal with the (unlikely) possibility that PanSTARRS needs to cancel one or more blank deliveries.
Finally, it is possible that experience with our first prototype telescope may justify building four substantially redesigned telescopes rather than just three additional copies of the prototype. Thus we may decide to purchase a total of five rather than four blanks.
In summary, please respond to this RFQ with the following separate alternate offers:
1. One mirror blank per specifications in this document to be delivered ASAP.
2. Four mirror blanks per specifications in this document; the first delivered ASAP followed by three more delivered on the best available schedule beginning in April 2005.
3. Five mirror blanks per specifications in this document, the first delivered ASAP followed by four more delivered on the best available schedule beginning in April 2005.
Offers shall specify a period of time during which the terms of the offer are valid.
Quotes should include a list of past customers who have purchased large optical blanks. Please identify any proprietary information in your quote.
Quotes will be accepted for consideration until May 24, 2004. Please return a initialized copy of the drawing PSTD-020-001-01 with your quote.
General
Each blank is to be a 100 mm (3.94″) thick 1.84 meter (72.44″) diameter meniscus perforated with a 0.90 meter (35.43″) diameter center hole. The concave surface will be optically figured by a qualified optician (not part of this RFQ) and used as the support for the optical reflecting surface (e.g. evaporated aluminum film). The convex surface will be used for attachment of mounting hardware to hold the mirror in the telescope.
Specification Applicability
All specifications in this document refer to the fully generated blank as delivered by the bidder.
Material
Material shall be a low expansion glass similar to Corning ULE® titanium silicate glass, Schott Zerodur®, or LZOS Astrositall®.
Coefficient of Thermal Expansion (CTE)
All CTE documentation, measurements and traceability shall be maintained.
The mean coefficient of thermal expansion (CTE) of all material in the mirror blank shall be 0 +/- 30 ppb/deg C over a temperature range of 0°C to 20°C with a 95% confidence level.
The radial CTE range of the blank shall not exceed 100 ppb/deg C.
The difference between average radial CTE for all boules used in the blank shall not exceed 20ppb/deg C.
Inclusions
Critical Zone (CZ )
The Critical Zone of the completely generated and delivered blank shall be defined as a zone of glass 0.200" (5mm) thick beginning at the concave surface (the surface that will support the optical reflecting surface) and includes material expected to be in the final clear aperture of the finished blank.
Inclusions in the CZ shall not exceed 2 mm (0.079″) in mean diameter.
The maximum number of inclusions per any cubic inch in the CZ shall not exceed 6.
The average number of inclusions per cubic inch in the CZ shall not exceed 0.2.
Should there be any fusion seams in the CZ, each shall be a minimum of 99% sealed.
In each fusion seam, the total area occupied by blisters and inclusions greater than 2mm (0.079″) in mean diameter shall not exceed 1.0% of the total area in that fusion seam.
The maximum dimension of any blister located wholly or partially in the CZ shall not exceed 5mm (0.197″) in its longest dimension.
There shall be no foreign material penetrating into the CZ.
Non Critical Zone
The non-critical zone is defined as all glass not contained in the critical zone.
Inclusions shall not exceed 10mm (0.394″) in mean diameter.
The average number of inclusions per cubic inch shall not exceed 0.6.
Fusion seams shall be a minimum of 98% sealed.
In each fusion seam, the total area occupied by blisters and inclusions greater than 2mm (0.079″) in mean diameter shall not exceed 2.0% of the total area in that fusion seam.
The maximum dimension of any blister shall not exceed 75mm (2.952″) in its longest dimension.
Internal Stress
The blank shall be measured for birefringence at 4 inch intervals along one radius of the blank. The birefringence resulting from permanent strain shall not produce a relative retardation of the path difference exceeding 20 nm/cm of light.
Generating
Bidder shall describe the machinery and methods to be used for generating. . All shaping shall be done using a precision Campbell generator or equivalent with the mirror blank rotating on a precision turntable. Alternative machines and/or methods of shaping may only be used with prior approval by the customer.
All surfaces of the generated mirror blank shall have a 120 grit fixed abrasive finish or better. Final full cuts (no skips) on the concave surface, inside diameter and outside diameter shall be completed and measured for specification values and TIR all in a single setup without moving the blank in the setup.
There shall be no fractures, gouges or chips anywhere in the blank.
There shall be no unacceptable checks or cracks in the finished blank. An unacceptable check or crack is one which has one or more ends which are unmodified or which has the potential for further propagation or which imparts significant structural degradation to the mirror blank.
Any inclusion, bubble or chip that intersects the exterior surface of the blank shall have its contours rounded out by fixed abrasive grinding to a 120 grit or finer finish.
Metrology
Vendor shall complete a data report for the mirror blank.
All measurement methods shall be described in detail indicating the equipment used (brand and model) along with a description of methods and procedures. A written record of measurement values shall be kept by the person making the measurements. These recordings and notes shall be included in the delivery documents along with a written certification that all dimensions and tolerances shown in these specifications have been met.
Non-conformances, either existing or anticipated, shall be documented as soon as known and submitted to the customer for resolution.
Dimensions/Tolerances
Outside diameter (OD) and inside diameter (ID) shall be concentric cylinders.
OD shall be 1840 +/- 1 mm (72.44 +/- 0.039″)
OD shall run true on the generator turntable to better than 0.2 mm (0.008″) TIR.
ID shall be 900 +/- 1mm (35.43 +/- 0.039″)
ID shall run true on the generator to better than 0.1 mm (0.004″) TIR.
ID and OD shall be concentric to +/- 0.3 mm (0.012″).
Radii of Curvature
The front (concave) and back (convex) sides of the blank shall have nominally a common center of curvature, that is, the blank will have a uniform thickness measured perpendicular to the two surfaces.
A concave spherical surface whose radius lies between 7877 and 7883 mm (310.12 and 310.35″) which fits the generated concave surface with no more than 0.2 mm (0.008″) of sag deviation shall meet the concave radius of curvature requirement. This surface will be finished by the optician as the optical working surface.
A convex spherical surface whose radius lies between 7977 and 7983 mm (314.06 and 314.29″) which fits the generated convex surface with no more than 0.5 mm (0.020″) of sag deviation shall meet the convex radius of curvature requirement. This surface will become the back of the mirror blank against which the axial mirror supports make contact.
Thickness
Nominal thickness measured perpendicular to the concentric curved surfaces shall be 100 +/- 1mm (3.94 +/- 0.039″).
Wedge
Thicknesses measured at a number of representative places on the blank including around the OD shall establish that the blank has no more than 0.5 mm (0.020″) of total wedge.
Chamfers
All sharp edges shall be chamfered at a nominal 45 degree angle and shall have a hypotenuse of width 6 +/- 1 mm (0.24 +/- 0.039″).
Progress Monitoring
Bidder shall briefly describe their policies regarding pre-arranged customer visits to the bidders manufacturing site for the purpose of monitoring progress. Describe restrictions and limitations if any.
Final Acceptance
Blank is to be placed on display for appropriate final inspection and acceptance by the customer's representative.
Packaging
Bidders are invited, at their option, to include as a separate line item a packing/shipping container suitable for safe transport of the blank by truck to an optical shop in the continental USA. Line item price shall be the total cost of the container itself along with cost of lifting the blank into the container and closing the container making it ready for pickup by the shipper.
Selection Criteria
Received quotes will be evaluated on price, delivery date, and previous performance as demonstrated by past customer satisfaction for delivery of large optical blanks.
Inquiries
Bidders may request clarification of any information contained in this document. All technical inquiries shall be transmitted via email to Mr. Edward Mannery at the address emannery@comcast.net. Procurement questions should be addressed to Jeff Morgan by calling (808) 988-8980 or by email at the address morgan@ifa.hawaii.edu