SuperCDMS Detector Readout Cryogenic Hardware

Abstract

Abstract. SuperCDMS employs 1-inch thick gennanium crystals operated below 50mK in a dilution cryostat. Each detector produces ionization and phonon signals. Ionization signals are amplified by JFETs operating at 150K within an assembly mounted on the 4K cryostat stage. These high impedance signals are carried to the FETs by superconducting "vacuum coaxes" which minimize thermal conductivity, stray capacitance, and microphonics. Transition edge sensors produce low-impedance phonon signals, amplified by SQUID arrays mounted on a 600mK stage. Detectors are mounted in a six-sided wiring configuration called a "tower", which carries signals from 40mK to 4K. A flex circuit 3 meters in length carries amplified signals for each detector from 4K to a vacuum bulkhead. We describe the methods used to support the detectors, wiring and amplifier elements at various thermal stages, minimizing electrical noise and thermal loads.

Testing and Characterization of SuperCDMS Dark Matter Detectors

“…A SQUID is a very sensitive magnetometer that, with the application of an inductor, can measure small currents very precisely. A more detailed overview of SuperCDMS signal readout and cold hardware including mechanical and thermal considerations can be found in [18].…”

A SQUID magnetometry system for a cryogenic neutron electric dipole moment experiment

“…SQUIDs (Superconducting Quantum Interference Devices) are sensitive instruments which exploit the phenomena of flux quantization and Josephson tunnelling to achieve a sensitivity to changes in the magnetic field at the femtotesla level [37,38]. They have found application as precision magnetometers in fundamental particle physics research in experiments searching for magnetic monopoles [39][40][41], and also as detector readout for superconducting TES sensors in dark matter experiments [42,43], and microwave detectors in axion searches [44].…”