The equipment is a cryostat that will be used in EH4624 for the testing of superconductor electronics integrated circuits. This cryostat will be used to cool down fabricated samples to a temperature of 4 Kelvin while providing all necessary thermal shielding to reach these temperatures, as well as wiring for electronic and optical readout and control of the samples at speeds ranging from DC (0 Hz) to 40 GHz. The system must provide a base temperature of 1-4.5 Kelvin, two temperature stages (the first between 10 and 100K and the second between 1-4.5 Kelvin) and a cooling power within the second temperature stage of at least 1.8 W. The system must also be a closed-cycle cryogen-free cryostat. The system must also include a compressor that is cooled by chilled water and is compatible with a 200 VAC 3-phase system. The system must include a temperature controller with temperature sensors that can be mounted at each temperature stage. The system must include space (e.g., room for sample holders) and wiring to support the independent testing of 3 integrated circuits simultaneously (each having at least 40 pins), and thus must provide per integrated circuit at least 20 pin feedthroughs for user wiring (for a total of at least 60), 18 flex coax feedthroughs for moderately high frequency signals (for use up to at least 15 GHz) (for a total of at least 54), and 2 semi-rigid cable feedthroughs for RF signals (for use up to at least 40 GHz) (for a total of at least 6). For faster cryostat warm-up speeds, the system must also include a heater and temperature sensor on the second stage to thermally control the cold plate. The room where the equipment will be located has electrical and weight restrictions. For weight, the equipment cannot weigh more than 1100 lbs. in total (excluding the compressor). For electrical, only single and 3-phase voltages are allowed at 120 VAC and 200-240 VAC voltages.
