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Influence of material and geometry of the dielectric on the characteristics of the tank circuit resonators for high-Tc RF-SQUID-based system
, Article IEEE Transactions on Applied Superconductivity ; Volume 26, Issue 3 , 2016 ; 10518223 (ISSN) ; Shanehsazzadeh, F ; Sarreshtedari, F ; Fardmanesh, M ; Sharif University of Technology
Abstract
Characteristics of a lumped element L-C tank circuit resonator of high-Tc rf-SQUIDs, which plays an important role in the device operation, have been experimentally investigated, according to the corresponding simulations obtained by COMSOL Multiphysics. We experimentally investigated the characteristics of the resonators by measuring their scattering parameters, as well as evaluating the rf-SQUID signal. Our SQUIDs are made of sputtered YBCO thin films with 3-mm-diameter washer areas. Different configurations of the resonator are investigated, and it is observed that, by increasing the thickness of the dielectric in a specific range, the reflection coefficient (S11) increases. For the...
Low noise SQUID based NDE with non-magnetic scanning system in unshielded environment
, Article Journal of Physics: Conference Series ; Volume 97, Issue 1 , 2008 ; 17426588 (ISSN) ; Alavi, M ; Sarreshtedari, F ; Vesaghi, M ; Banzet, M ; Schubert, J ; Fardmanesh, M ; Sharif University of Technology
Institute of Physics Publishing
2008
Abstract
A Non-magnetic scanning Robotic system with special EMC considerations has been designed for SQUID-Based NDE of room temperature stationary samples in unshielded environment. Considerable efforts have been made to cancel out noise of the system which resulted in detection of two major noise sources. Characterizing the noise contribution of the involved parts, a minor noise component was found to be due to the robot and the other due to liquid nitrogen bubbling in some frequencies which could be avoided by choosing proper excitation frequency. Using our NDE system we performed a NDE scan of hidden cracks in aluminum plates with white noise level of 50 μΦ0/ Hz-1/2. © 2008 IOP Publishing Ltd
Optimization of NDE characterization parameters for a RF-SQUID based system using FEM analysis
, Article IEEE Transactions on Applied Superconductivity ; Volume 19, Issue 3 , 2009 , Pages 791-795 ; 10518223 (ISSN) ; Sarreshtedari, F ; Pourhashemi, A ; Ansari, E ; Vesaghi, M. A ; Schubert, J ; Banzet, M ; Krause, H. J ; Sharif University of Technology
2009
Abstract
We have investigated the dependence of the optimal Non Destructive Evaluation (NDE) characterization on different excitation parameters in an eddy current SQUID NDE system for samples with known flaw depths. The considered parameters in our study include the configuration of the excitation-coil and its current frequency. The system is based on a High-YBCO gradiometer RF-SQUID sensor with a flux noise level below 100 μa I-y/Hz at 100 Hz in an unshielded environment, while being shielded against external rf EMI (Electromagnetic Interference). According to experimental results and the associated numerical analysis using Finite element (FEM) simulations, we have derived the optimized parameters...
Effect of rf pumping frequency and RF input power on the flux to voltage transfer function of rf-SQUIDs
, Article IEEE Transactions on Applied Superconductivity ; Volume 17, Issue 2 , 2007 , Pages 676-679 ; 10518223 (ISSN) ; Eker, T ; Bozbey, A ; Fardmanesh, M ; Schubert, J ; Banzet, M ; Sharif University of Technology
2007
Abstract
We present the results on the correlation between the flux to voltage transfer function, Vspp, of the rf-SQUID and the rf-bias frequency as well as rf-bias power. Measurements were performed for different SQUID gradiometer samples chosen from the same batch or different batches. In order to have full control on the electronics parameters, an experimental rf-SQUID circuit was designed and implemented with an operation frequency of 600 MHz to 900 MHz. According to our findings, It has been observed that at any particular rf-bias power, Vspp vs. rf-bias frequency shows Sine-like behavior. We observed that the main lobe maxima exist close to the resonance frequency of the LC tank circuit and by...
RF SQUID electronic readout system for the frequency range of 650MHz to 1GHz with automatic parameter setting
, Article Proceedings - 2010 18th Iranian Conference on Electrical Engineering, ICEE 2010, 11 May 2010 through 13 May 2010 ; 2010 , Pages 442-445 ; 9781424467600 (ISBN) ; Razmkhah, S ; Alavi, M. H ; Fardmanesh, M ; Sharif University of Technology
Abstract
A RF SQUID electronic system has been implemented which works at the frequency range of 650MHz to 1GHz. By incorporating particle swarm algorithm for the optimization of the system parameters, the readout system could automatically set its parameters for a desired RF SQUID. Using the implemented system, the noise characteristics of a RF SQUID gradiometer is being measured. The measured flux noise of the High-Tc YBCO magnetometer is below 100μ Φ0/ √ Hz at 100Hz in unshielded environment
Optimization of a/b-axis regions of YBCO thin film for sensor applications
, Article Proceedings of the National Academy of Sciences India Section A - Physical Sciences ; Volume 88, Issue 4 , 2018 , Pages 625-628 ; 03698203 (ISSN) ; Hosseini, M ; Fardmanesh, M ; Sharif University of Technology
Springer
2018
Abstract
The effect of substrate temperature on epitaxial growth of Y1Ba2Cu3O7−x film deposited on (100) crystalline lanthanum aluminate (LAO) substrates by RF Sputtering method has been investigated. The crystal mismatch between film and substrate is about 1.6%. The sputtering was carried out in vacuum with base pressure better than 10−5 Torr and 10/20 Pa oxygen/argon partial pressures. Substrate temperature at this condition is about 730 °C based on Bormann–Hammond diagram. As well known, because of the small lattice mismatch between YBCO and LAO, fabricated thin films are not perfectly c-axis and there is tendency to form a/b-axis regions in the film. Due to substantial effects of the density and...
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 Optimization of RSFQ Based Digital SQUID for High Sensitive Measurement of Widely Varying Magnetic Fields
, Ph.D. Dissertation Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
Analog SQUIDs have limited slew rate and dynamic range and these problems make it hard to operate SQUID systems in unshielded applications like Bio-magnetic imaging and NDE. Recently by combining analog SQUIDs and RSFQ Logic, new class of magnetic sensors are introduced. These sensors have an acceptable sensitivity and very high dynamic range. On the other hand these sensors, Which are called Digital SQUIDs, can be directly connected to digital signal processing stages. In This work, for first time, a digital SQUID completely based on i-directional RSFQ was designed and optimized. using Bi-directional RSFQ, one can significantly simplify the digital SQUID circuit design and therefore...
Design and Optimization of HTS SQUID based Magnetocardiography using Active Shield
, Ph.D. Dissertation Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
In this work, we report on a developed single-channel high-Tc SQUID based MCG system for operation in unshielded environment. In brief, our system consists of a liquid Nitrogen Dewar and two high-Tc rf-SQUID capsuled in a holding probe,which is connected via coaxial cables to our multichannel rf-SQUID readout electronics.The rf-SQUIDs were patterned from about 200 nm△10 nm thick YBCO films sputtered on 1 mm thick LaAlO3 substrates. The holding probe integrates rf-SQUIDs, LC resonant circuits, and shielding coils. We have investigated the effects of the lumped element tank circuit resonator parameters on the rf-SQUID signal characteristics and based on the simulation and experimental...
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...
Optimization of SQUID NDE for Detection of the Defects in Metallic Samples
, Ph.D. Dissertation Sharif University of Technology ; Fardmanesh, Mahdi (Supervisor) ; Kokabi, Hamid (Supervisor)
Abstract
The purpose of this thesis is the incorporation of RF SQUID ultra-sensitive magnetic sensors in an implemented SQUID NDE system and also the development of associated inverse solution algorithms for the detection of defects in metallic samples. The system is based on the induction of Eddy currents and the incorporation of SQUIDs for precise detection of the magnetic field anomalies related to the defects in the sample. One of the major parts of the system is the highly stable, multi-channel RF SQUID readout system which has been designed and implemented with novel features for this project. For the magnetic inverse analysis of our SQUID NDE measurements, new models have been presented for...
An efficient finite-element approach for the modeling of planar double-D excitation coils and flaws in SQUID NDE systems
, Article IEEE Transactions on Applied Superconductivity ; Volume 20, Issue 2 , 2010 , Pages 76-81 ; 10518223 (ISSN) ; Pourhashemi, A ; Asad, N ; Schubert, J ; Banzet, M ; Fardmanesh, M ; Sharif University of Technology
2010
Abstract
Incorporating an efficient approach for the finite-element simulation of eddy current superconductive quantum interface device (SQUID) nondestructive evaluation (NDE) systems, an appropriate finite-element method (FEM) has been presented for simulating and analyzing such systems. We have introduced a new model for the planar double-D coils, which are used as the excitation source in eddy current SQUID NDE systems, and also another model for the description of the flaw effect on the induced current. We have also examined our simulation results with their associated measurements. Our system is based on a high-TC YBCO gradiometer RF-SQUID sensor with a flux noise level below 100 μΦ0 √Hz at 100...
Fast fourier transform based NDT approach for depth detection of hidden defects using HTS rf-SQUID
, Article IEEE Transactions on Applied Superconductivity ; Volume 28, Issue 7 , 2018 ; 10518223 (ISSN) ; Shanehsazzadeh, F ; Fardmanesh, M ; Sharif University of Technology
Abstract
We present a new approach for depth detection of hidden defects based on the analysis of the frequency spectrum of the output waveform in a nondestructive testing (NDT) system. In our eddy current Superconducting quantum interference device (SQUID) based NDT system, we apply multiple frequencies to its single excitation coil in a magnetically unshielded environment. The excitation coil is a planar D-shaped printed circuit board coil, and a high-Tc gradiometer YBCO rf-SQUID is used as the electromagnetic sensor in this system. An automated two-dimensional nonmagnetic scanning robot is used to test samples with intentional defects at different depths. In this approach, a diagram labeled 'FFT...
Analytical model for the extraction of flaw-induced current interactions for SQUID NDE
, Article IEEE Transactions on Applied Superconductivity ; Volume 21, Issue 4 , 2011 , Pages 3442-3446 ; 10518223 (ISSN) ; Hosseini, M ; Razmkhah, S ; Mehrany, K ; Kokabi, H ; Schubert, J ; Banzet, M ; Krause, H. J ; Fardmanesh, M ; Sharif University of Technology
Abstract
Incorporating an analytical approach to simulate the interaction of a series of long cracks and the induced current of a double-D excitation coil, we have developed a model-based method to do precise detection of the positions of the cracks in a metallic structure by using eddy-current superconducting quantum interference device (SQUID) nondestructive evaluation (NDE) measurements. Conventionally, the structure of the defects is found by iteratively solving a numerical forward problem, which is usually based on finite-element, boundary-element, or volume-integral method. This, however, incurs a heavy numerical burden, as every time the forward problem is to be solved, a rigorous numerical...
Design & Implementation of Fluxgate Based Active Shield for Using in SQUID Based Magnetocardiograghy
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
Superconducting Quantum Interference Devices (SQUIDs) are one of the most sensitive magnetic flux detectors. According to their high sensitivity, these sensors have many applications such as magnetic imaging, magnetocardiography and magnetoencephalography. In this project we have designed and implemented a fluxgate based active shield that would be used in magnetocardiography. One of the main concerns in RF-SQUID applications is suppression of the low and high frequency noises. These noise sources includes earth magnetic force, humming noise and RF noise caused by cell phones. These sources could unlock RF-SQUID sensors and hence needs to be shielded. Low frequency noise suppression could be...
Design and Implementation of Vibrating Sample Magnetometer Based on Gradiometer RF SQUID
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mehdi (Supervisor)
Abstract
The aim of this project is design and implementation of the “gradiometer RF SQUID base Vibrating Sample Magnetometer (VSM)”. Different sections of the system have been designed such as pick up coils, vibration system and electronic circuits. The piezoelectric crystal has been concerned for vibration system. At the first step, we have implemented the basic VSM system. In the basic system, voltage induces in two series opposite pick up coils and its output is recognizable via electronic circuits. At the second phase of the project, the electronic circuits of basic VSM system have been replaced with the RF SQUID gradiometer and its electronic circuits. Afterwards, the sensitivity and the gain...
Design and Fabrication of an Integrated Superconducting Resonator/Flux Concentrator for rf SQUID Magnetometer
, M.Sc. Thesis Sharif University of Technology ; Fardmanesh, Mahdi (Supervisor)
Abstract
Ultra-sensitive magnetometers based on Radio Frequency Superconducting Quantum Interference Device (rf SQUID), have wide applications in Non-destructive Evaluation (NDE), geophysical measurements and biomagnetic measurements, especially in magnetocardiography (MCG) systems. A superconducting module coupled to rf SQUID is designed to provide a resonance frequency in GHz range (according to the electronic system frequency), as well as concentrating the magnetic flux in the effective area of SQUID. The signal can be measured through a port pumping AC power to the module. The resonator has been also implemented by lumped element tank circuits, but the quality factor of these circuits are usually...
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...
Design and optimization of fully digital SQUID based on bi-directional RSFQ
, Article Journal of Superconductivity and Novel Magnetism ; Vol. 27, issue. 7 , 2014 , p. 1623-1628 ; Bozbey, A ; Fardmanesh, M ; Sharif University of Technology
Abstract
Bi-directional RSFQ benefits from using both positive and negative SFQ pulses to manipulate and transfer digital data. This allows more flexibility in the design of simpler circuits with enhanced performance. On the other hand, using the AC bias current, one can replace on-chip resistive current distributors with inductors. This resembles RQL logic, but in contrast to RQL, it is possible to use the well-established standard RSFQ cells in bi-directional RSFQ. These two advantages (energy-efficient computation and flexibility in design) make bi-directional RSFQ a powerful tool in next-generation supercomputers and also compatible with ultra-low-temperature quantum computers. In this work, to...
Signal enhancement techniques for rf SQUID based magnetic imaging systems
, Article Superconductor Science and Technology ; Volume 19, Issue 8 , 2006 , Pages 821-824 ; 09532048 (ISSN) ; Fardmanesh, M ; Schubert, J ; Zander, W ; Banzet, M ; Lomparski, D ; Schmidt, M ; Krause, H. J ; Sharif University of Technology
2006
Abstract
We have investigated the rf SQUID (radio-frequency superconducting quantum interference device) and its coupling to tank circuit configurations to achieve an optimal front-end assembly for sensitive and high spatial resolution magnetic imaging systems. The investigation of the YBCO rf SQUID coupling to the conventional LC tank circuits revealed that coupling from the back of the SQUID substrate enhances the SQUID signal while facilitating the front-end assembly configuration. The optimal thickness of the substrate material between the SQUID and the tank circuit is 0.4 mm for LaAlO3 resulting in an increase of the SQUID flux-voltage transfer function signal, Vspp, of 1.5 times, and 0.5 mm for...