Feedback solutions for low crosstalk in dense arrays of high-T-c SQUIDs for on-scalp MEG
Journal article, 2017

Magnetoencephalography (MEG) systems based on a dense array of high critical temperature (high-T-c) superconducting quantum interference devices (SQUIDs) can theoretically outperform a state-of-the-art MEG system. On the way towards building such a multichannel system, we evaluate feedback methods suitable for use in dense high-T-c SQUID arrays where the sensors are in very close proximity to the head (on-scalp MEG). We test on-chip superconducting coils and direct injection of the feedback current into the SQUID loop as alternatives to the wire-wound copper coils commonly used in single-channel high-T-c SQUID-based MEG systems. For the evaluation, we have performed coupling, noise, and crosstalk measurements. We conclude that direct injection is the optimal solution for dense on-scalp MEG as it gives crosstalk below 0.5% even between SQUIDs whose pickup loops are within 0.8 mm of one another. Further, this solution provides sufficient flux coupling without adding additional noise. Finally, it does not compromise the standoff distance, which is important for on-scalp MEG.

multichannel crosstalk

SQUID

high-temperature

on-scalp magnetoencephalography

Author

Silvia Ruffieux

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Minshu Xie

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Maxim Chukharkin Leonidovich

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Christoph Pfeiffer

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Alexei Kalaboukhov

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Dag Winkler

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Justin Schneiderman

University of Gothenburg

Superconductor Science and Technology

0953-2048 (ISSN) 1361-6668 (eISSN)

Vol. 30 5 art. nr 054006-

Subject Categories

Medical Engineering

Condensed Matter Physics

DOI

10.1088/1361-6668/aa65a2

More information

Latest update

2/21/2018