If ultra-low noise performance is required, our integrated two stage devices are the number one choice.
With input inductances from 24 nH to 1.8 µH and a flux-noise level as low as 0.8 µPhi0/sqrt(Hz) an energy resolution of about 45 h is attained.
The devices consist of a 16 SQUID series array as amplifier stage and a single front-end SQUID.
Coupling between feedback and input coils is minimized. So, the change in feedback sensitivity with open and shorted input coil is less than 1 %.
The single-SQUID-like V-Phi characteristics of the devices together with the built-in features for two-stage SQUID operation of our XXF-1 electronics makes working point adjustment nearly as convenient as with single stage sensors.