Developments in Time-Division Multiplexing of X-ray Transition-Edge Sensors

Area of Science:

• Physics
• Instrumentation
• Astrophysics

Background:

• Time-division multiplexing (TDM) is a standard readout technique for transition-edge sensors (TESs).
• TDM systems commonly utilize superconducting-quantum-interference-device (SQUID) current amplifiers.
• Previous TDM applications include gamma-ray and X-ray microcalorimeter spectrometers, and astronomical cameras.

Purpose of the Study:

• To present details of two distinct TDM system versions for X-ray TES readout.
• To evaluate the performance and noise characteristics of these TDM systems.
• To demonstrate the energy resolution achievable with a novel TDM architecture.

Main Methods:

• Developed and deployed two TDM readout systems with varying SQUID stages and switching speeds.
• Characterized readout noise for both three-SQUID-stage (0.41 microΦ0/√Hz) and two-SQUID-stage (0.19 microΦ0/√Hz) architectures.
• Tested a multiplexed array of NIST TESs with the new TDM architecture.

Main Results:

• Field-deployed TDM systems successfully operated 160- and 240-sensor X-ray spectrometers.
• The developed two-SQUID-stage TDM system achieved significantly lower readout noise (0.19 microΦ0/√Hz).
• A 32-row NIST TES array demonstrated an average energy resolution of 2.55±0.01 eV at 6 keV.

Conclusions:

• The presented TDM systems are effective for reading out X-ray TES arrays.
• The new two-SQUID-stage TDM architecture offers improved noise performance.
• This advancement holds promise for enhanced energy resolution in microcalorimeter-based spectroscopy.