Turbo-Brayton Refrigerator for High Temperature Superconducting Device

Scanning superconducting quantum interference device microscope in a dilution refrigerator

We report on a scanning superconducting quantum interference device microscope operating at temperatures down to 20 mK in a dilution refrigerator. The instrument is designed for studying quantum mechanical coherence effects in mesoscopic systems and investigating magnetic effects on a mesoscopic length scale in novel materials. We have demonstrated the low-temperature operating capabilities of ...

Superconducting cascade electron refrigerator

Disposable sample holder for high temperature measurements in MPMS superconducting quantum interference device magnetometers.

A sample holder for high temperature (300 K<T<800 K) measurements in superconducting quantum interference device magnetometers is presented. It is fabricated using aluminum foil and it is appropriate for samples in either solid or powder form. The holder is homogeneous for the gradiometer coil, and this results in a contribution to the background signal that is below the instrument noise at any...

Superconducting transmission lines for use in a He dilution refrigerator

We compare two superconducting transmission lines for use in a He dilution refrigerator using a NbTi wire inner conductor with NbTi foil and CuNi tubing outer conductors. The heat transfer is calculated using the Wiedermann-Franz Law, and the impedance and power loss are measured using a network analyzer at room temperature and at 4K. The transmission line with CuNi tubing is easy to construct,...

Interstage Heating and Cooling Options for High Temperature Helium Brayton Cycles

This report summarizes work to examine interstage heating and cooling options for multiple reheat helium Brayton cycle power conversion system (PCS) designs. Previous work has demonstrated that thermal powers in the range of 2400 MWt can be readily derived from combining multiple single-expansion units derived from the 600-MWt, vertical shaft gas-turbine module helium reactor (GT-MHR). This PCS...