SQUID Readout Electronics and Magnetometric Systems for Practical Applications

Feedback Concepts and its History8.2 SQUID's apparent parameters8.3 Parallel Feedback Circuit (PFC)8.3.1 Working Principle of the PFC in Current Bias Mode8.3.2 Working Principle of PFC in Voltage Bias Mode8.3.3 Brief Summary of Qualitative Analyses of PFC8.4 Quantitative analyses and experimental verification of the PFC in voltage bias mode8.4.1 The equivalent circuit with the PFC in voltage bias mode8.4.2 Introduction of Two Dimensionless Parameters r and ¿8.4.3 Numerical calculations8.4.4 Experimental Results8.4.5 Noise Comparison and Interpretation8.4.6 Two practical designs for PFC8.5 Main achievements of PFC quantitative analysis8.6 Comparison with the noise behaviors of two preamplifiers9 ANALYSES OF THE "SERIES FEEDBACK COIL (CIRCUIT)" (SFC)9.1 SFC in current bias mode9.1.1 Working principle of the SFC in current bias mode9.1.2 Noise measurements of a weakly damped SQUID (magnetometer) system with the SFC9.2 The SFC in voltage bias mode9.3 Summary of the PFC and SFC9.4 Combination of the PFC and SFC (PSFC)9.4.1 PSFC analysis under independence conditions9.4.2 PSFC experiments and results9.4.3 Conclusion of the PSFC10 WEAKLY DAMPED SQUID10.1 Basic consideration of weakly damped SQUID10.2 SQUID system noise measurements with different ssc values10.3 Statistics of SQUID properties10.4 Single chip readout electronics (SCRE)10.4.1 Principle of SCRE and its performance10.4.2 Equivalent circuit of SCRE10.4.3 Differences between the conventional version of readout electronics with an integrator and SCRE10.4.4 Two applications of SCRE10.5 Suggestions for the DRS11 TWO-STAGE AND DOUBLE RELAXATION OSCILLATION READOUT SCHEMES11.1 Two-stage scheme11.2 ROS and DROS11.3 Some comments on D-ROS and two-stage scheme12 RADIO-FREQUENCY (RF) SQUID12.1 Fundamentals of an rf SQUID12.2 Conventional rf SQUID system12.2.1 Block diagram of rf SQUID readout electronics (the 30 MHz version)12.2.2 rf SQUID system noise in the 30 MHz version12.3 Introduction to modern rf SQUID systems12.3.1 Magnetometric thin-film rf SQUID and a conventional tank circuit with a capacitor tap12.3.2 Improved rf SQUID readout electronics12.3.3 Tank circuit operating up to 1 GHz with inductive coupling12.3.4 Modern rf SQUID system12.3.5 Substrate resonator12.3.6 Regarding the rf SQUID?s thermal noise limit12.4 Further developments of the rf SQUID magnetometer system12.4.1 Achievement of a very large delta V_rf/delta Phi in a low-impedance system12.4.2 Multiturn input coil for a thin-film rf SQUID magnetometer with a planar labyrinth resonator12.4.3 Modern rf SQUID electronics12.5 Multichannel high-Tc rf SQUID gradiometer12.6 Comparison of rf SQUID readout with dc SQUID readout12.7 Summary and outlook

visiting Ph.D. student at the Forschungszentrum Jülich, before becoming Assistant and in 2015 Associate Professor at SIMIT CAS. His research interests include SQUID design and fabrication, and SQUID applications in biomagnetism, geophysics and related areas. He has authored and co-authored about 20 scientific publications, and he holds 5 patents.Hans-Joachim Krause received his Ph.D. in Physics from RWTH Aachen, Germany in 1993. He initiated the Non-destructive Evaluation Group at Forschungszentrum Jülich, working on projects with industrial partners for the development of SQUID systems for the magnetic testing of aircraft parts, pre-stressed concrete bridges and other structures. In summer 2011, he was a Visiting Professor at Université Pierre et Marie Curie, Paris, France. Currently, he leads the Magnetic Sensing Group in Jülich, focusing on SQUID sensors, magnetic biosensing, low field nuclear magnetic resonance, magnetic immunoassays and magnetic nanoparticle actuation. In 2017, he was appointed Professor of Physics at the University of Applied Sciences, Aachen, Germany. He has co-authored more than 150 scientific publications with over 1500 citations.