SOW_final.pdf

Attachment A – NIST SSD Cryogen-Free Optical Cryostat System

Statement of Work

Background:

The National Institute of Standards and Technology (NIST) Physical Measurement Laboratory (PML)

Sensor Science Division (SSD) laboratory develops and tests cryogenic optical detectors and sources, primarily for infrared calibrations. This cryogen-free low temperature optical measurement system will enable SSD to test cryogenic optical detectors, optical materials and thermometers at operational temperatures from 4 K to 20 K without the use of liquid helium or liquid nitrogen. Liquid helium, in particular, is a limited and expensive resource, costing the SSD facility approximately $40000 per year.

SSD’s goal is to replace its cryogen-based systems with cryo-cooler systems wherever possible, to protect against future cost increases in liquid helium as well as supply interruptions.

Scope:

Design and fabricate a cryogen-free low temperature optical measurement system capable of sustained operation with sample temperature at 4 K. An appropriate system would include a helium compressor, a cryo-cooler refrigerator, an optical cryostat, and control electronics. The detailed requirements for these components are itemized below.

Contract Line Item (CLIN) 0001: The Contractor shall provide all parts, labor, and material for a quantity of one (1), Cryogen-Free Low Temperature Optical Measurement System, meeting or exceeding the following minimum technical requirements:

1. Refrigerator:

a. base temperature < 4 K

b. > 0.1 W of cooling power at 4.2 K

c. > 4 W of cooling power at the first stage (temperature < 60 K)

d. temperature-control for refrigerator

2. Compressor:

a. electrical: 200 V 3-phase or 120 V single phase, 60 Hz

b. power consumption < 20 kW

c. if water cooled, then < 25 L/min cooling water required

d. < 3 kW of power dissipated into the surrounding air

e. Noise < 70 dB at distance of 0.5 m

3. Optical Cryostat:

a. Sample volume > 100 mm in diameter and > 70 mm high

b. Sample cold plate > 100 mm in diameter, with grid of threaded holes for mounting measurement fixtures. Sample cold plate must have base temperature < 5.5 K.

c. Includes electrical feedthroughs containing at least 50 pins, in addition to manufacturer-supplied thermometers and heaters

d. Cold shield which can reach a base temperature < 5 K included around sample volume

e. At least one optical port with diameter of approximately 50 mm at outside of cryostat and diameter > 25 mm at the innermost port. Must have fittings to allow user to mount own windows or filters at the optical ports.

f. Includes multi-turn valve to evacuate vacuum space and safety pressure release valve for vacuum space

4. Cooldown time for the measurement volume from 300 K to 5 K shall be < 16 hours.

5. Temperature stability of the measurement cold plate shall be < 250 mK. (Stronger consideration shall be given to a contractor who provides the lowest temperature stability)

Attachment A – NIST SSD Cryogen-Free Optical Cryostat System

6. The amplitude of vibrations at the measurement cold plate shall be < 50 µm. (Stronger consideration shall be given to a contractor who provides the lowest amplitude of vibrations)

7. Control electronics necessary for operation of the system (e.g., temperature control) shall be included. All necessary accessories for operation (e.g., flexible cables from compressor to cryo-cooler) shall be included. Any software necessary for operation shall be included.

CLIN 0002: Option Line Item – Upgrade of System to reach temperature no more than 1 K at Sample

Stage.

Deliverables

Deliverable 1: The Contractor shall provide 100 percent complete mechanical design drawings and interface specifications, prior to fabrication, for Government review not later than 4 weeks after receipt of the order. The draft design shall be evaluated by the Government Technical Point of Contact within 1 week from receipt of the draft and provide a response indicating either acceptance or revisions required.

The Contractor shall submit the drawings electronically. PDF format or Word document.

Deliverable 2: The Contractor shall deliver the final system not later than 5 months after acceptance of the 100 percent final design.