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Announcement of Opportunity No. N251228

Precision Radial Velocity Spectrometer (PRVS) Design Studies

Gemini Observatory
Issued: 24 August 2005
Requests for RFP Due: 9 September 2005

The Association of Universities for Research in Astronomy, Inc. (AURA), acting as operator of the Gemini Observatory, intends to solicit proposals to conduct conceptual design studies of a Precision Radial Velocity Spectrometer (PRVS). In the near future AURA will be issuing a Request for Proposals (RFP) to institutions that submit a request to receive the RFP by the date given above. Requests to receive the RFP should be sent by email to Andrew Flach, Gemini Contracts Manager, at, and should reference “N251228” in the subject line. In the body of the email please give the name of your institution and the contact information (name, email, street address, and telephone) for the person who will serve as your single point of contact for this procurement.

The total funding available for these design studies is USD 1,000,000, which includes funding for both direct and indirect (i.e., the equivalent of overheads) costs. Gemini plans to use this funding to award design study contracts to nominally two competing design teams. It is anticipated that the design study phase will start in December 2005 and be completed no later than September 2006. The design studies will include optical, mechanical, electronic, and software design elements, at the conceptual level, as needed to demonstrate the technical viability of the approach used. The studies will also be used to define a fixed cost for completing the instrument.

Subsequent to completion of the Conceptual Design study phase, a ~3 year development program is envisioned for this instrument. Funding to build the PRVS has not yet been secured. Initial cost estimates for this instrument, including the cost of this design study activity, is approximately USD 7,000,000 and this figure should be used as an upper limit when preparing proposals. The final decision as to whether or not to build a PRVS for Gemini will not be made until the results of the other instrument studies are evaluated and funding options for all proposed new Gemini instrumentation are better defined.

PRVS Description

The detection of terrestrial-class extra-solar planets around low-mass stars through Doppler reflex measurements is the primary scientific goal of the PRVS. This instrument is expected to provide ~0.9 to 1.8 µm high-resolution spectroscopy with very high stability over several years, so that orbiting planets can be discovered. Unlike other Gemini facility instruments, PRVS will not be mounted on the Cassegrain Instrument Support Structure, but will rest on the ground in a bench mounted gravity-stable configuration. It is anticipated that light will be collected via a fiber interface contained in a GMOS mask cartridge (like bHROS), and transferred to the PRVS via fiber optic cable. The PRVS is expected to be delivered with pipeline processing software as part of the overall instrument package.

The preliminary baseline performance requirements for the PRVS include:

  • Wavelength range: 0.9 to approximately 1.8 µm
  • Field of view: minimum ~1.2 arcsec fiber entrance aperture (a significant fraction of the light must be coupled into the fiber, even during worse-than-median seeing conditions)
  • Spectral resolution: R ~ 70,000
  • Simultaneous wavelength coverage: entire 0.9 to 1.8 µm range (goal)
  • Long-term velocity stability: < 3 m/s, with a goal of 1 m/s

The long wavelength cutoff will be a compromise between the need to detect an adequate number of absorption lines for accurate reflex measurements and instrument cooling requirements, since it is not expected that the bulk of the instrument will be cryogenic. High velocity stability will be a key performance indicator of this instrument. The design teams will be required to explore all aspects of the design relevant to achieving this velocity precision (including mechanical, thermal, optical, environmental and calibration system stability) on the time-scales relevant for planet detection, and to demonstrate the ability to achieve these precisions via system end-to-end simulation.

Please note that these requirements may be modified or expanded in the actual RFP and are only meant to give a general idea of the scope of the work. Do not rely on the requirements stated in this announcement in performing any work.

These design guidelines are intended to focus but not completely constrain the conceptual design activities. Modifications of these guidelines based on scientific, technical, or cost considerations will be considered through the design study phase of the program.

Use of Existing Designs

Gemini in general promotes the use of pre-existing designs when developing new instrumentation. The use of such component designs help reduce costs, deployment times, development risks, and maintenance demands of Gemini’s facility instruments. Accordingly detailed mechanical design information about any of Gemini’s delivered facility class instruments will be made available upon request to interested design teams when Requests for Proposals are distributed. Teams may propose to use alternate designs for any subassembly but will be at a competitive disadvantage in the evaluation process if it is practical to use a pre-existing design from another instrument instead.

Any National Gemini Office (NGO), collaboration of NGO's, institution, or company within any Gemini Partner country is entitled to propose for the development of one or more conceptual designs of the PRVS. Interested teams should not begin work on their proposals until they have received the actual Request for Proposal document, which contains specific instructions regarding the content and format of proposals.

Gemini Observatory Participants