(VI) Description of requirements is as follows: One each of CLIN 0001, 0002, 0003, 0004;
CLIN 0001:
1. The ADR refrigeration system must have a demonstrated record of being used to cooled superconducting transition-edge sensors. References are required here.
2. Delivery of the system must be within 5 months.
3. The unit must be capable of obtaining a base temperature < 100mK and maintaining this temperature in excess of 7 days per cooling cycle without a heat load.
4. The unit shall maintain mechanical vibrations at a level that does not interfere with experiments on an optical table.
5. The unit shall be cryogen-free, not requiring liquid nitrogen or liquid helium for operation.
5. The cryocooler must have a cooling power >0.5W at 4.2K for heat sinking many copper wires.
6. The vacuum feedthroughs must be standard KF fittings. There must be at least three KF fittings. At least two must be KF40 or larger.
7. A remote valve for the cryocooler to reduce EMI from the compressor
8. There must be a stage of cooling below 1K for cooling wires that will be connected to electronics at 3K and the detectors at the base temperature.
9. The system must include a power supply to energize the magnet.
10. The system must include the capability to regulate the temperature of the base temperature stage by controlling the current in the magnet.
11. The temperature of the 1st stage must be <50K.
12. The temperature of the 2nd stage must be <3K with the ADR unit installed.
13. There must be radiation shields at the 1st stage (< 50K) temperature of the cryocooler.
14. There must be a radiation shield at the 2nd stage (< 3K) temperature of the cryocooler.
15. There must be enough penetrations through the 1st radiation shield for wiring so that at least 7 micro-d connectors can be mounted. Each micro-d connector will contain 25 connections. The penetrations needed for the thermometry are not included in this count.
16. There must be enough penetrations through the 2st radiation shield for wiring so that at least 3 micro-d connectors can be mounted. Each micro-d connector will contain 25 connections.
17. There must be an area of at least 5" x 5" on the 2nd stage that is unoccupied and can be used to mount NIST made printed circuit boards for superconducting electronics.
18. There must be suitable scheme for mounting wiring to the 1K cooling stage.
19. There must be a suitable area for mounting devices to the base temperature stage.
20. The volume of work space that is enclosed by the 4K radiation shield must be large enough so that a 1" x 1" x 4" volume of copper can be mounted at the base temperature stage. In the volume of workspace, suitable room must be there to accommodate 100 twisted pairs of wires and 24 optical fibers.
CLIN 0002:
21. There must be a stand for the remote valve.
CLIN 0003:
22. There must be a stand to hold the ADR.
CLIN 0004:
23. The system must include a thermometry system that monitors the temperature of the stages of the cryocooler, magnet, 1K stage, and base temperature stage.
The readout of the base temperature stage must use a low-noise lock-in amplifier so that minimal excitation current is used to measure the temperature.