Attachment_B-_Specifications_.pdf

Attachment B

SPECIFICATIONS

Brand Name or Equal Dry Dilution Refrigerator System

PURPOSE:

The system National Institute of Standards and Technology (NIST) seeks to procure is a dry dilution refrigerator that will be used to characterize Nano electronic devices at cryogenic temperatures and microwave frequencies. Specifically, it will be used to investigate superconducting quantum bits, ultrasensitive microwave detectors, and superconducting amplifiers. For these studies, NIST requires a multi-stage vacuum cryostat with a base temperature stage that reaches 10 mK and experimental electrical wiring going from 300 K to the base temperature stage.

TECHNICAL SPECIFICATIONS OF THE DEVICE:

The Device must be a Bluefors Cryogenics Oy Ltd LD-250 or be a technically equivalent cryostat. The following is a list of required features:

1.1 Physical

- Stand-alone operation, i.e., no excess equipment such as additional vacuum pumps shall be needed to operate the Device.

- The supporting structure such as the floor mount must be included.

- Extensive vibration isolation including a remote rack-mounted turbo pump with bellows and pulse tube bellows damping stage. Horizontal and vertical mechanical vibrations at the base flange (due to the pulse tubes) shall be characterized by the vendor and be less than 10 micro meter average displacement for all low frequencies (< 500 Hz).

- Mixing chamber plate with diameter of 29 cm or more.

- Radiation and magnetic shielding shall be included:

• A tin-plated Cu radiation shield shall be included to protect devices at the base temperature stage from thermal radiation and ambient flux noise

• An additional magnetic shield shall be included to protect devices at the base temperature stage from ambient flux noise.

- An integrated thermal link between 50 K stage and the still-stage for the purpose of speeding-up the final part of the cool-down shall be included.

1.2 Performance of the refrigerator

- Cryogen-free operation, i.e., pulse tube cooler is used instead of liquid helium to cool down to 4 K.

- Guaranteed base temperature of 10 mK or below.

- Cool-down time of less than 24 h.

- Cooling power of at least 40 W at 45 K, at least 1.5 W at 4.2 K, and at least 300 microwatts at 100 mK.

1.3 Vacuum system

- No membrane pump shall be used in the 3He—4He mixture circulation since they have short service periods and the rupture of the membrane leads potentially to loss or contamination of the mixture.

- The dilution unit shall not have any soft solders. Soft-solders are known to develop micro-fractures and cold leaks overtime.

1.4 Operation

- Heat-exchange-gas-free operation, i.e., the Device shall have only a single vacuum feedthrough stage at room temperature, which implies that no heat exchange gas can be used in the large vacuum can.

- Fully automated operation with computer-controlled valves and pumps.

- Press-of-a-button cool-down possibility.

- Possibility to control the Device with user-written software (e.g. Python, LabView and

MATLAB) running on an additional user-supplied computer.

- A panel with the possibility to override the automation and to fully control the Device manually.

1.5 Supplies

The following accessories must be supplied by the vendor:

- Temperature measurement and control equipment including thermometers and a high-level resistance bridge with a PID controller such as Lakeshore 372S/AC. The resulting temperature stability at the mixing chamber plate must be accurate on the sub-millikelvin level below 100 mK. Thermometers at all plates at different low temperatures must be included.

- Seven or more line-of-sight ports at least 40 mm in diameter.

- A warm-up heater, installed, for faster warm-up of the refrigerator. The warm-up heater must include at least one heating element on the 4 K plate and a programmable power supply. The refrigerator must warm up in 13 hours or less using the warm-up heater.

1.6 Experimental and Technical Wiring

- Experimental wiring of 12 or more single Thermocoax lines (e.g. type 1 Nc Ac, 0.5 mm OD) including installation and thermalization from room temperature to base temperature, and a break-out box with an SMA connector for each wire at room temperature and a breakout with an SMA connector for each wire at base temperature.

- Experimental wiring of 12 or more phosphor-bronze twisted pairs including installation and thermalization from room temperature to base temperature, and break-out box with a standard connector for each wire at room temperature and a standard connector for each wire at base temperature.

- Experimental wiring of 12 or more Cu + NbTi/CuNi low-ohmic superconducting twisted pairs including installation and thermalization from room temperature to base temperature, and a break-out box with a standard connector for each wire at room temperature and base temperature.

- Experimental wiring of 12 or more twisted pairs (e.g. 35 AWG Cu) from room temperature to the 4 K stage. This set of wires shall include anchoring to the pulse tube and standard connectors at room temperature and 4 K. The purpose of these lines is to power user-supplied commercial low noise microwave amplifiers operated at the 4 K stage.

- Microwave experimental wiring of twelve (12) or more “SMA” lines shall be supplied and installed. The lines shall be designed to operate up to 18 GHz or higher frequency and be fitted with SMA connectors and thermal anchoring at multiple stages.

• Nine (9) of the SMA lines shall be supplied and installed for the purpose of sending microwave signals to electrical devices at the base temperature stage. These lines should be equipped with appropriate levels of cryogenic attenuation for blocking 300 K radiation and reducing the noise temperature of input signals. For example, the following attenuation scheme is appropriate: 50 K (0 dB), 4 K (20 dB), Still 1 K (10 dB), Cold Plate

0.1 K (20 dB), mixing-chamber 0.01 K (20 dB).

• Three (3) of the SMA lines shall be supplied and installed for the purpose of measuring signals originating from the base temperature stage. On these lines, a minimal amount of attenuation should be present, with no attenuation between 4 K and the base temperature stage.

- Microwave experimental wiring of one (1) or more “SMK” lines with K-2.92 mm connectors and thermal anchoring for frequencies up to 40 GHz or higher from room temperature to base temperature including installation. Coaxial cables equipped with cryogenic attenuation at all stages shall be included with a scheme similar to: 50 K (0 dB), 4 K (20 dB), Still 1 K (10 dB), Cold Plate 0.1 K (20 dB), MXC 0.01 K (20 dB).

- A pair of current leads (rated to 100 amperes or more) including installation going from a room temperature feedthrough to electrical connectors at the 4 K plate. The purpose of these leads is to power a user-supplied (and user-installed) superconducting solenoid magnet that operates at the base temperature.

1.7 Documentation

Full technical documentation and user manuals in English must be included as pdf-files and in printed format.

2 Description of services, warranty and after sales support

2.1 Factory testing

Factory tests with the full provided system must be carried out before delivery and installation. The optimization of the helium mixture and the operation of the automated cool-down must be included and carried out in this configuration.

2.2 Training

Training on site for 2 days immediately after accepted installation.

2.3 Warranty

Warranty period of at least three years for the components manufactured by the supplier and for the installation of third-party components. One-year or longer warranty for other components. Warranty shall cover all labour, travel, parts, and other costs required for maintaining the guaranteed performance of the device. Warranty will take effect on the day of final acceptance. In case of warranty repair, the service shall begin no later than three business days from the moment the customer notifies the supplier.

3 Installation location

3.1 Physical characteristics of the installation location

- The Device will be installed in a laboratory space that is not electrically shielded.

- Space for pumps and gas handling systems is immediately nearby.

- The installation location is situated on the ground floor of the building.

- The installation site can be examined by the supplier beforehand. Requirements for the site must be supplied at least 3 months beforehand. The supplier must check before signing the contract that the installation location fully corresponds to the requirements (electromagnetic noise, vibration level, etc.).

3.2 Available supplies at the installation location

- Standard USA 60 Hz, 110 V / 220 V electric power and 200/230VAC, 3 Phase, 60 Hz electric power available in the laboratory.

- Cooling water is available at the installation location.

- Building-wide pressurized air is available at the installation location.

DELIVERABLE SCHEDULE: Within 6 months after receipt of order (ARO).