Specification_-Close-Cycle_Liquid_helium_Cryostat_System.pdf

Specifications

Close-Cycle Liquid Helium Cryostat System

BACKGROUND:

The National Institute of Standards and Technology (NIST) is conducting quantum communication research including the NIST Innovations in Measurement Science (IMS) project, “quantum randomness as a secure resource”. NIST needs a pair of the state of the art newly developed superconducting nanowire single photon detectors (SNSPDs) to detect single photons in the telecom wavelengths.

NIST is in need of a full SNSPD system consists of superconducting nanowire detector elements, a cryostat, a helium compressor and controlling electronics. The nanowire elements are made of superconducting material and mounted inside the cryostat. Typical cryocoolers with two stages can reach temperatures as low as 2.5 Kelvin (2.5K). With the addition of a sorption fridge, 0.8K temperatures can be achieved.

DESCRIPTION/PURPOSE OF ITEM/SERVICE TO BE ACQUIRED:

(Including function to be performed, performance requirement or essential physical characteristics)

The required minimum specifications for the cryogenic system we request are as following:

General Description:

An automated, closed-cycle cryostat capable of reaching 0.8K temperature with at least

24 hour hold time. The cryostat should be designed to house superconducting nanowire single photon detectors (SNSPDs) and include readout and control wiring and electronics.

Base components:

A cryostat based on closed-cycle, Gifford-McMahon cryocooler

A sorption fridge with base temperature 0.8 K and hold time at least 24 hours

6 inch outer diameter of the cryostat with 8 KF40 ports, with one port used for control wiring

The cryocooler must be compatible with a water-cooled Helium compressor (Sumitomo model HC-4E2) that is already owned by NIST. We do NOT wish to buy an additional

He compressor.

Temperature controllers with sensors for operation at 40K, 4K and 0.8K and heaters at

40K and 4K stages

8 SMA electrical inputs with proper heat sinks

Lossless optical feedthroughs for 8 SMF28 fibers with FC/PC input ports

Computer software to control cooldown, cycling, scheduling of cycles, graphical monitoring, and temperature logging

Optional Components Separately Priced to be exercised no later than September 30, 2017).:

Set of 4 low-noise amplifier/bias tee modules to readout SNSPDs, with mounting enclosure on a KF40 port of the cryostat https://inet.nist.gov/pco/services/ims

Oil-free roughing and turbo pumping station and vacuum gauge with associated control software. Also includes vacuum fittings and interface cables

Integration and installation of up to 4 third-party SNSPD devices

On-site installation and training

Electronics for biasing 4 SNSPD elements including:

o 17-inch wide mainframe with GPIB communications o 4 isolated voltage sources that can supply 20V o A quad digital voltmeter with 5½ digit display and 19.9999 V range

NIST has previously purchased a water-cooled, closed-cycle helium compressor (Sumitomo model HC-4E2). The requested cryogenic system requested here must be compatible with the

HC-4E2 model.