[MMR Technologies]
Variable Temperature Hall Dewar


The VTHS Dewar is a low-profile Dewar designed to fit between the poles of a magnet to enable measurements to be made of the resistivity, Hall mobility and other properties of materials over a wide range of temperatures. Guarded triax leads provide electrical input to the sample via similarly guarded leads on a Kapton Harness to the sample on the cold stage. A Hall sensor immediately adjacent to the sample allows measurement of the magnetic field at the sample location. 

In addition to the refrigerator and vacuum chamber, a temperature controller is needed, either manual or programmable; a source of dry nitrogen (99.998% purity); a filter dryer; and a vacuum pump capable of maintaining a vacuum <5 mTorr in the chamber. Other accessories that add to the convenience of operating the system are available from MMR.



  • Operating Temperature: 70 K to 730 K
  • Temperature Stability: ± 0.1 K with MMR's Programmable Controller
  • Temperature Response: 1 K/sec
  • Cooling Capacity: 250 mW at 85 K with nitrogen; 500 mW with Ar at 90 K
  • Cold Pad Size: 14 mm x 10 mm
  • Standard Window Material: Fused silica
  • Optional Window Materials: Sapphire, Quartz.
  • Guarded triax leads to sample
  • Four sample leads for Van der Pauw measurements
  • Extra BNC lead for heater for Seebeck measurements
  • Simple sample mounting
  • Integral Hall sensor at sample site
  • Compatible with two different MMR electromagnets, allowing maximum flexibility in sample analysis
  • Dewar Dimensions: 6.0" L x 2.5" W x 0.75" H at sample
  • Weight of Vacuum Chamber: 170 g (6 oz)