Mechanical Cryocooler System for the NIST Primary Optical Watt Radiometer (POWR)

Maryland

08/04/2025 01:50 PM EDT

08/05/2025 12:00 AM EDT

COMMERCE, DEPARTMENT OF - NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY - DEPT OF COMMERCE NIST

*****THIS IS A COMBINED SOURCES SOUGHT NOTICE AND NOTICE OF INTENT TO SOLE SOURCE***. 

BACKGROUND 

The National Institute of Standards and Technology (NIST) requires a closed-cycle mechanical cryocooler system to be used to cool its Primary Optical Watt Radiometer (POWR) to its operating cryogenic temperature of 4.2 K. POWR is an absolute cryogenic electrical substitution radiometer that serves as the Nation’s optical power reference for realization of the SI scale of optical power. It measures the optical power from a minimally diverging light source, typically a laser beam, and uses that same light source to then calibrate the responsivity and quantum efficiency of different types of detectors, typically photodiodes, which are used by other key facilities at NIST as optical power standards across the ultraviolet, visible, and infrared spectrum. POWR is currently operated in a traditional liquid helium cryostat, where it is surrounded by vacuum and cooled to 4.2 K. To alleviate concerns about the future availability of liquid helium, NIST plans to move the POWR Module from the liquid helium cryostat to a new system, 

NIST is seeking information from sources that may be capable of providing a solution that will achieve the objectives described above, in addition to the following essential requirements 

Contract Line-Item Number (CLIN) 0001: The Contractor shall provide one (1) mechanical cryocooler system.   

The system shall meet or exceed the technical specifications identified below. All items must be new.  Used or remanufactured equipment will not be considered for award. Experimental, prototype, or custom items will not be considered.  The use of “gray market” components not authorized for sale in the U.S. by the Contractor is not acceptable.    

Migrate a pre-existing K2-IS camera from a pre-spectrometer position of a pre-existing ETEM energy filter to a post-spectrometer position to enable direct-detection spectrum imaging. 

1. Technical Specifications 

Must consist of a helium gas compressor, closed-cycle mechanical cryocooler, cryostat, temperature controller, and vacuum controller, all with supporting electronics to fully automate the evacuation, cooldown, temperature stabilization, and warmup of the cryostat without the need for additional equipment.  

Helium Gas Compressor:  

1. The compressor must fit into a space 24 inches wide x 24 inches deep x 48 inches tall.  

1. The compressor electrical power requirements must be any combination of:  

1. Single Phase 200 – 250 VAC, 60 Hz  

1. Three Phase 200 – 250 VAC, 60 Hz  

1. Single Phase 110 – 120 VAC, 60 Hz  

1. The compressor will be in a service galley behind the POWR lab and must operate in an ambient environment between 17 deg. C and 28 deg. C.  

1. The compressor must accept inlet cooling water temperatures between 5 deg. C and 25 deg. C and flow rates between 6.8 liters/minute and 9 liters/minute; the outlet temperature of the return water must be less than 45 deg. C.  

1. The length of the supply and return lines that supply helium gas between the compressor and the cryocooler must be at least 18 m, but not more than 30 m. These lines must be flexible enough to make a 90 degree turn out of the compressor, go vertical to the ceiling in the service galley behind the POWR lab, make 90 degree turn to go horizontal along the ceiling in the service galley, make a 90 degree turn into the POWR lab, make a final pair of 90 degree (or less) turns to connect to the cryocooler inside of the POWR lab.  

1. The compressor must be fully integrated with the control electronics of the cryocooler system to allow it to be controlled remotely from the main controller.  

Cryocooler and Cryostat:  

1. The cryocooler must cool the cryostat cold plate to an operating temperature of   

4.2 K and provide for at least 250 mW of cooling power to remove heat deposited on the cold plate while the cold plate is at 4.2 K.  

1. The cryocooler must provide sufficient cooling power to enable a cryostat cold plate cooldown time of fewer than 7 hours from room temperature to 4.2 K without the POWR Module or its Adaptor installed.   

1. The time required to warm up the cryostat cold plate from 4.2 K to room temperature must be no longer than 5 hours without the POWR Module or its Adaptor installed.  

1. The peak-to-peak temperature fluctuations of the cryostat cold plate at the operating temperature (4.2 K) must be below 20 millikelvin.  

1. The peak-to-peak vibration level of the cryostat cold plate with the cryocooler running at full speed and connected to the cryostat but isolated from the optical table on which the cryostat is mounted, must be below 30 nanometers.  

1. The rigidly connected parts of the cryocooler and cryostat must fit into a space that is, at maximum, 55 inches deep (along the optical axis). However, at maximum, only 35 inches can sit atop an optical breadboard table; therefore, at maximum, 20 inches could extend off the backend of the optical breadboard table. The other dimensional constraints for the rigidly connected parts of the cryocooler and cryostat are 34 inches in width and 60 inches in height. Non-rigidly connected parts, such as rack-mounted electronics connected by electrical cables, are not required to fit (and will not fit) within this space so must be compatible with placement 1 meters minimum from this space.   

1. The cryocooler and cryostat electrical requirements are 120 VAC, 60 Hz, 15 A maximum current draw per outlet, connectable to standard NEMA 5-15 wall outlets.  

1. The cryostat must include a cold plate upon which the POWR Module will be mounted by a set of bolts through the POWR Module Adaptor (by the user after delivery), a user-mounted/demounted radiation shield to surround the POWR Module and its Adaptor, one optical port, built-in temperature sensors and heaters for cryostat diagnostics and control, and electrical cabling for the POWR Module (to be detailed in requirement 26). A drawing of the POWR Module Adaptor currently used with the liquid helium cryostat is attached for reference. The requirement to provide a lightweighted POWR Module Adaptor is described separately in requirement 31.   

1. The cryostat must provide a space large enough to contain the POWR Module Adaptor (with socket head cap screw bolts – not shown in the attached drawings – holding it together) with the POWR Module axis (center of circle of Heat Sink – see page 4 of attached drawings) coinciding with the cryostat optical axis.  

1. The cryostat must be provided with a single optical port and be fitted with a 6-inch conflat flange having its center on the cryostat optical axis. A mating 6-inch conflat flange containing a simple flat 1-inch minimum diameter clear window must be installed on this optical port to enable cryostat vacuum testing and cryogenic testing. This window will simulate the amount of room-temperature infrared blackbody radiation that the cold-plate will have to accept during user operation. After delivery and acceptance, the user will remove this flat window conflat flange and replace it with the current 6-inch conflat flange Brewster-window section that is currently used with POWR in the liquid helium cryostat. This Brewster-window section is not part of the current procurement.  

1. The cryocooler and cryostat will be mounted on a large movable optical breadboard table that frequently moves 1 meter horizontally in the direction perpendicular to the optical axis – driven by a motorized stage controller – during operations. This is to permit the POWR Module to be moved out of the way of the incident laser beam so that it can be applied to the detectors being calibrated. The cryocooler and cryostat must function properly under these conditions, including all rigid connections required between parts of the cryocooler and cryostat, and any required auxiliary equipment connected by non-rigid cables or plumbing. Therefore, mounting of rigid cryocooler components on the moving optical breadboard must be considered instead of mounting on the fixed laboratory floor.   

1. The distance between the (horizontal) cryostat optical axis and the top surface of the existing movable optical breadboard on top of which the cryostat is to be mounted must be 8.25 inches +/- 0.25 inches. The cryostat and/or any fixtures on which it is to be mounted must be designed so that this requirement is met.  

1. The cryostat radiation shield must block all room-temperature radiation except that entering through a hole centered on the optical axis. The diameter of this hole must be no smaller than 0.5 inches, defined by a circular metal aperture with edges beveled to a knife edge, which is then mounted (and removable via 6 screws/bolts) on the radiation shield. The aperture must be machined from the same material as the radiation shield. Dimensions must be within the following constraints: minimum thickness of 1 mm, bevel at 45 degrees, maximum knife edge radius 10 microns, and all dimensions within a 10 percent tolerance. This hole is required to allow a laser beam from a room-temperature laser to enter the POWR Module. Estimates of the heat load entering the cryostat cold plate must accept the room-temperature infrared blackbody radiation entering this hole. Since POWR is potentially used at all wavelengths from 190 nm through far-infrared, no cryogenic optics may be placed along the laser path from room-temperature to POWR, so this infrared heat load must be absorbed by the cryostat and removed by the cryocooler even after the cold plate is cooled to 4.2 K.  

1. The 0.5-inch diameter aperture on the cryostat radiation shield must be the minimum aperture between the optical window conflat flange and the location of the POWR Module. All other holes that form the optical access to the cryostat must have diameter greater than 0.5 inch.  

1. When determining if the offered product meets the 4.2 K base temperature requirement on the cold plate, in addition to the standard heat loads, the following possibly non-standard thermal loads must be contemplated: a) infrared radiation entering the radiation shield (since there is no cold filter on the radiation shield); b) the laser power, up to 1 mW, absorbed by the POWR Module that will need to be dissipated by the cold plate; c) heat conduction from the 32 phosphor-bronze leads that connect POWR signals from room temperature to the POWR Module (detailed in requirement 26).  

1. The cryocooler must be accompanied with any vacuum system required for its operation, including any electronic or computer hardware or software.  

1. The cryostat must have second 6-inch conflat vacuum flange for a user-provided turbo pump to enable the user to pump the cryostat vacuum to 10 microtorr at room temperature. The outgassing properties and leak integrity of the cryocooler/cryostat must be compatible with the user reaching 10 microtorr. For example, no unused flex cables or other materials that would present unnecessary outgassing sources should be used.  

1. The cryostat must include getters to improve vacuum under cryocooling conditions.  

1. The cryostat must include customized wiring for the POWR Module consisting of 32 phosphor-bronze wires having vacuum/cryogenic-compatible insulation, twisted in pairs (16 pairs total), leading from two (2) standard DB-25 pin feedthrough connectors on the room-temperature-side to a special user-provided 32-pin connector to be mounted on the cold plate next to the POWR Module. Appropriate heat sinking of all 32 wires to intermediate temperature stages must be provided. The 32-pin connector must be heat sunk to the cold plate in a way that facilitates connecting and disconnecting to the POWR Module electrical cable, which is a mating 32-pin connector. A quantity of 4 of these 32-pin connectors will be provided to the vendor (one to use, three spares in case needed), since it is anticipated that these are difficult for the vendor to purchase. These are vacuum compatible and cryogenic compatible connectors that NIST has used on a variety of cryostats in the past, including POWR. A picture of this type of 32-pin connector to be provided by NIST to the vendor is inserted at the bottom of this document. A wiring diagram mapping the pins of the 32-pin connector to the pins of the two DB-25 connectors will be provided to the vendor after award.  

1. The cold plate must include a set of tapped holes matched to the lightweighted POWR Module Adaptor (described in requirement 31). If the cryostat cold plate contains tapped holes that would be beneath the POWR Module Adaptor, then additional considerations must be taken as described in requirement 31.    

1. The cryostat control software must accept remote control and remote viewing connections.  

1. The cryostat software must be capable of running automated program scripts from MATLAB, LabVIEW, and Python.  

1. The system must include lift rings if a crane is necessary to enable installation. The POWR lab has a crane that may be used by NIST staff during installation.  

Lightweighted POWR Module Adaptor:  

1. The POWR Module Adaptor surrounds the POWR Module and adapts it to the cold plate within the cryostat. The existing POWR Module Adaptor is unnecessarily massive (~11 lbs), so this requirement is to produce a lighter-weight version of the POWR Module Adaptor to replace the existing one when POWR is mounted into the cryostat. Since this massive object is anticipated to determine much of the cooldown time of the cryocooled system, a 50 % reduction of mass is a goal. The POWR Module Adaptor holds the POWR Heat Sink and facilitates routing of the POWR cabling from the 32-pin connector to four, 8-pin connectors on the POWR Heat Sink. No changes need to be made to the Power Adaptor Cable Covers, Adaptor Back Cover, or POWR Heat Sink, so these do not need to be re-made and should not be part of the quote. The lightweighted POWR Module Adaptor must be made from oxygen-free-high-conductivity (OFHC) copper and gold-plated (with a buffer metal for adhesion) on all surfaces with a specular finish for vacuum integrity and infrared radiation control. It must have identical tapped holes as that shown in the drawing for accommodating the Heat Sink, identical center bore, identical tapped holes on the back for accommodating the Adaptor Back Cover, and slots and tapped holes for accommodating the POWR cables and Adaptor Cable Covers. It also must place the optical axis of the POWR Module (center of the Heat Sink) so that it is aligned with the cryostat optical axis and provide clearance holes on the bottom that match those of tapped holes in the cryostat cold plate. If the cryostat cold plate contains tapped holes that would be beneath the POWR Module Adaptor, then additional grooves on the bottom of the POWR Module Adaptor must be machined to avoid virtual leaks.  

  

NIST conducted market research from October 2024 – February 2025 by, speaking with colleagues, performing internet searches, and speaking with vendors to determine what sources could meet NIST’s minimum requirements.  The results of that market research revealed that only MONTANA INSTRUMENTS CORPORATION, INC. (UEI UPLFDS3YE7W9:) can meet all the Governments minimum requirements.  

HOW TO RESPOND TO THIS NOTICE 

In responding to this notice, please DO NOT PROVIDE PROPRIETARY INFORMATION. Please include only the following information, readable in either Microsoft Word 365, Microsoft Excel 365, or .pdf format, in the response:  Submit the response by email to the Primary Point of Contact and, if specified, to the Secondary Point of Contact listed in this notice as soon as possible, and preferably before the closing date and time of this notice.  Please note that to be considered for award under any official solicitation, the entity must be registered and “active” in SAM at the time of solicitation response. 

• Provide the complete name of your company, address, name of contact for follow-up questions, their email, their phone number and, if your company has an active registration in https://sam.gov, your company’s Unique Entity ID (UEI). 

• Details about what your company is capable of providing that meets or exceeds NIST’s minimum requirements. 

• Whether your company is an authorized reseller of the product or service being cited and evidence of such authorization. 

• Identify any aspects of the description of the requirements in the BACKGROUND section above that could be viewed as unduly restrictive or create unnecessary barriers that adversely affect your firm’s ability to fully participate in a procurement for such services and explain why.  Please offer suggestions for how the requirements could be organized or structured to encourage the participation of small businesses. 

• For the NAICS code  

• Indicate whether your company is (a) a small business or (b) other than small business.  See the Table of Small Business Size Standards and the associated .pdf download file for small business size standards and additional information. 

• If you believe the NAICS code listed in this notice is not the best NAICS code for the type of product addressed in this notice, identify an alternative NAICS code that you believe would be more appropriate for the planned procurement.  

• If your firm has existing Federal Supply Schedule contract(s) or other contracts for products or services against which the Department may be able to place orders, identify the contract number(s) and other relevant information. 

• Describe your firm’s experience (as a prime, subcontractor, or consultant) providing the products or services described in Background section. 

• Provide any other information that you believe would be valuable for the Government to know as part of its market research for this requirement. 

• Please let us know if you would like to engage to get a better understanding of the requirement or need additional information about the Government’s requirement for the products or services described in the Background section.  

QUESTIONS REGARDING THIS NOTICE 

Questions regarding this notice may be submitted via email to the Primary Point of Contact and the Secondary Point of Contact listed in this notice. Questions should be submitted so that they are received by July  25, 2025. If the Contracting Officer determines that providing a written amendment to this notice to document question(s) received would benefit other potential respondents, the questions would be anonymized, and a written response to such question(s) would be provided via an amendment to this notice. 

IMPORTANT NOTES 

The information received in response to this notice will be reviewed and considered so that the NIST may appropriately solicit for its requirements in the near future.   

This notice should not be construed as a commitment by the NIST to issue a solicitation or ultimately award a contract.   

This notice does not obligate the Government to award a contract or otherwise pay for the information provided in response. 

This notice is not a request for a quotation. Responses will not be considered as proposals or quotations. 

No award will be made as a result of this notice.   

NIST is not responsible for any costs incurred by the respondents to this notice. 

NIST reserves the right to use information provided by respondents for any purpose deemed necessary and appropriate. 

  

Any organization responding to this notice should ensure that its response is complete and sufficiently detailed to allow the Government to determine the organization’s capability.  

Respondents are advised that the Government is under no obligation to acknowledge receipt of the information received or provide feedback to respondents with respect to any information submitted.  

Thank you for taking the time to submit a response to this request.