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Design and Implementation of a SQUID Based Magnetic Detection System Using Active and Passive Shielding
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mahdi (Supervisor)
Abstract
Superconducting SQUID sensors are one of the most sensitive magnetic sensors that have been ever produced. Due to their high sensitivity, these sensors have many applications in different fields. Magnetic Imaging and far away targets detections are of these applications. In this project, a magnetic imaging system based on Superconducting SQUID sensors have been designed and implemented. In SQUID applications one of the most important problems is the cancelation of the unwanted fields including background low frequency and high frequency fields. In residential and urban areas the interference of Electricity network is considered as one of the major noise sources. While the high frequency...
Design and Fabrication of Sensor Probe and Active Noise Reduction Circuit for SQUID MCG System in Magnetically Unshielded Environment
,
M.Sc. Thesis
Sharif University of Technology
;
Fardmanesh, Mehdi
(Supervisor)
Abstract
Characterization of local magnetic activity of the heart muscles is named magnetocardiography (MCG), which measures magnetic field generated by electrical activity around heart. RF SQUID sensors are appropriate choice for measuring magnetic activity of the heart muscles. Because squid detects weak signals as low as fTesla, while heart magnetic field is near 50 pt which is one millionth of earth magnetic field and thousands of time weaker than the environment noise. One of the problems of mcg system is its urgency to shielding of unwanted magnetic field. In this project design of holders and resonators for well coupled input coil with RF SQUID is improved. As a result, at the first stage...
Low noise active shield for SQUID-Based mag-netocardiography systems
, Article IEEE Transactions on Applied Superconductivity ; 2017 ; 10518223 (ISSN) ; Fardmanesh, M ; Sharif University of Technology
Abstract
light weight and low-cost active magnetic shield sys-tem is proposed for a single channel SQUID-based magnetocardiog-raphy system equipped for operating at liquid nitrogen temperature without passive magnetic shield. The developed active shield, using coils around the sensors, is a two-stage magnetic shielding system, each stage of which has been designed to compensate different fre-quency and dynamic ranges. The sensor part contains two high-Tc rf-SQUID magnetometers, capable of working stably under earth magnetic field, placed in an axial gradiometric arrangement with a baseline of 10 cm. The active shield setup is driven using two corre-lated proportional-integral-derivative closed loop...
Low noise active shield for SQUID-based magnetocardiography systems
, Article IEEE Transactions on Applied Superconductivity ; Volume 28, Issue 4 , 2018 ; 10518223 (ISSN) ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2018
Abstract
A light weight and low-cost active magnetic shield system is proposed for a single channel SQUID-based magnetocardiography system equipped for operating at liquid nitrogen temperature without passive magnetic shield. The developed active shield, using coils around the sensors, is a two-stage magnetic shielding system, each stage of which has been designed to compensate different frequency and dynamic ranges. The sensor part contains two high-Tc rf-SQUID magnetometers, capable of working stably under earth magnetic field, placed in an axial gradiometric arrangement with a baseline of 10 cm. The active shield setup is driven using two correlated proportional-integral-derivative closed loop...
Design and optimization of feedback control system for active shielding of HTS RF-SQUID based MCG
, Article 24th Iranian Conference on Electrical Engineering, ICEE 2016, 10 May 2016 through 12 May 2016 ; 2016 , Pages 457-459 ; 9781467387897 (ISBN) ; Majzoubi, M ; Kalantari, N ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
A High Tc RF-SQUID Based magnetocardiography system is developed for operating in a passively unshielded environment, in which active shielding is implemented to compensate field noises for the low to midrange frequency range. The main part of the implemented active shield configuration is a feedback control system designed for environmental noise cancelation in particular that of the power lines. This control system includes two layers of inner and outer compensation coils with respect to the liquid Nitrogen Dewar as parts of the designed active shield. The inner coils are surrounding the HTS SQUIDs which are placed in axial gradiometric configuration inside the dewar. The outer coils are...
Shielding factor enhancement method for Bi-stage active shield in SQUID-based magnetocardiography system
, Article 29th Iranian Conference on Electrical Engineering, ICEE 2021, 18 May 2021 through 20 May 2021 ; 2021 , Pages 129-133 ; 9781665433655 (ISBN) ; Esmaeili, F ; Shanehsazzadeh, F ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
We proposed a simple method to enhance shielding factor of our previously proposed bi-stage active shield system employed in a SQUID-based magnetocardiography system. The additional proposed design is optimized for canceling the power-line magnetic interference field to provide a calmer magnetic environment for the bi-stage active shield. A 50 Hz cancellation coil is placed around the bi-stage shielding system which includes inner and outer coils designed for compensating low-frequency (0-0.1Hz) and high-frequency (0.1-100Hz) environmental magnetic noise, respectively. In this configuration, a SQUID magnetometer is located at the center of these coils. Considering that the power-line...
Shielding factor enhancement method for bi-stage active shield in SQUID-based magnetocardiography system
, Article 29th Iranian Conference on Electrical Engineering, ICEE 2021, 18 May 2021 through 20 May 2021 ; 2021 , Pages 129-133 ; 9781665433655 (ISBN) ; Esmaeili, F ; Shanehsazzadeh, F ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
We proposed a simple method to enhance shielding factor of our previously proposed bi-stage active shield system employed in a SQUID-based magnetocardiography system. The additional proposed design is optimized for canceling the power-line magnetic interference field to provide a calmer magnetic environment for the bi-stage active shield. A 50 Hz cancellation coil is placed around the bi-stage shielding system which includes inner and outer coils designed for compensating low-frequency (0-0.1Hz) and high-frequency (0.1-100Hz) environmental magnetic noise, respectively. In this configuration, a SQUID magnetometer is located at the center of these coils. Considering that the power-line...
Comparison of noise reduction techniques in RF SQUID magnetic detection systems
, Article Proceedings - 2010 18th Iranian Conference on Electrical Engineering, ICEE 2010, 11 May 2010 through 13 May 2010 ; 2010 , Pages 446-449 ; 9781424467600 (ISBN) ; Sarreshtedari, F ; Forooghi, F ; Fardmanesh, M ; Schubert, J ; Banzet, M ; Sharif University of Technology
Abstract
The noise level of the magnetometer and gradiometer RF SQUIDs were investigated using different shielding methods. The used methods include different active and passive shielding, such as Helmholtz configurations, locally compensation coils, superconducting bulks and μ-metal shields. For the passive shielding approach, using FEM simulation we have investigated the shielding effectiveness of superconducting bulks versus the use of μ-metal shielding. The superconducting shield is a YBCO circular bulk, which was made using melt-texture method and located in a distance in front of the SQUID. In this work the results of these shielding methods are presented and compared, while their effectiveness...