Frequency-domain multiplexed readout of transition-edge sensor arrays with a superconducting quantum interference device

摘要

We demonstrate an eight-channel frequency-domain readout multiplexer for superconducting transition-edge sensors (TESs). Each sensor is biased with a sinusoidal voltage at a unique frequency. The sensor currents are summed and measured with a single superconducting quantum interference device (SQUID) array. The 100-element SQUID array is operated with shunt feedback electronics that have a slew rate of 1.2 X 10~7Φ_0/s at 1 MHz. The multiplexer readout noise is 6.5 pA/(Hz)~(1/2), which is well below the expected sensor noise of 15 pA/(Hz)~(1/2). We measure an upper limit on adjacent channel crosstalk of 0.004, which meets our design requirements. The demodulated noise spectra of multiplexed TESs are white at frequencies down to 200 mHz.