Superconducting Quantum Interference devices and readout of cryogenic particle detectors

Gen Uehara, Masanori Higuchi

Michiel J. van Duuren

This thesis describes the development of low Tc superconducting quantum interference devices (SQUIDs) based on the relaxation oscillation principle. SQUIDs are the most sensitive magnetic flux sensors available nowadays. As they can detect very accurately any physical quantity that can be converted to a magnetic flux, their field of applications is wide-ranging. Examples of applications are the detection of the tiny magnetic fields generated by the human brain, the measurement of voltages in the picovolt range and the readout of cryogenic particle detectors.

Michael Mück, Matthias Korn, Chas Mugford +1 more

We have designed and tested a superconducting quantum interference device (SQUID) readout circuit, which can be operated at liquid helium temperatures. Although room-temperature SQUID electronics perform well, it is sometimes desirable to keep the wires between SQUID, readout electronics, and feedback coil as short as possible to minimize phase shifts and time delays. Cooling the readout circuit to low temperatures can also decrease its thermal noise. Our readout circuit uses conventional ac-flux modulation, which significantly reduces low frequency excess noise and drift in the preamplifier. In this case, simple complementary metal–oxide–semiconductor circuits with low power dissipation can be used as amplifier, phase-sensitive detector and integrator. The power dissipation of the complete readout is less than 15mW at 5V supply voltage.

John L. Clarke

Nathan Bluzer, Martin G. Forrester

The discovery of high-temperature superconductors (HTS) spawned many potential applications, including optical detectors. Realizing viable superconducting detectors requires achieving performance superior to competing and more mature semiconductor detector technologies, and quantum detector technologies in particular. We review why quantum detectors are inherently more sensitive than thermal or bolometric detectors. This sensitivity advantage suggests that for operation at cryogenic temperatures, we should be developing only quantum superconducting detectors. Accordingly, we introduce and describe the structure and the operation of a superconducting quantum detector with a superconducting quantum interference device (SQUID) readout circuit. The superconducting quantum detector, consisting of a superconducting loop, produces a photosignal in response to photoinduced changes in the superconducting condensate's kinetic inductance. The superconducting quantum detector is designed to operate only in the superconducting state and not in the resistive or transition states.

James Edward Zimmerman