Articles | Volume 1, issue 2
https://doi.org/10.5194/mr-1-225-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/mr-1-225-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Topologically optimized magnetic lens for magnetic resonance applications
Sagar Wadhwa
Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Mazin Jouda
Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Yongbo Deng
State Key Laboratory of Applied Optics (SKLAO), Changchun Institute of Optics, Fine Mechanics and Physics (CIOMP), Chinese Academy of Sciences, Dongnanhu Road 3888, Changchun 130033, China
Omar Nassar
Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Dario Mager
Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
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Paul Jelden, Magnus Dam, Jens Hänisch, Martin Börner, Sören Lehmkuhl, Bernhard Holtzapfel, Tabea Arndt, and Jan Gerrit Korvink
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2025-10, https://doi.org/10.5194/mr-2025-10, 2025
Preprint under review for MR
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High critical field superconductors are less sensitive to magnet quenching, providing even higher fields. They can be cooled using cryogens like Helium, but simply using an oscillating pressure field. Using solar or wind energy, the cheap cooling promises magnetic resonance at high field, low operating cost, and renewable energy. Such magnets, made compact, can be used to prepolarise chemical samples, to be analysed in benchtop NMR systems, with better nuclear magnetic resonance spectra.
Sagar Wadhwa, Nan Wang, Klaus-Martin Reichert, Manuel Butzer, Omar Nassar, Mazin Jouda, Jan G. Korvink, Ulrich Gengenbach, Dario Mager, and Martin Ungerer
Magn. Reson., 6, 199–210, https://doi.org/10.5194/mr-6-199-2025, https://doi.org/10.5194/mr-6-199-2025, 2025
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We present a technology that allows for the direct writing of conductive tracks on cylindrical substrates as receiver coils for magnetic resonance (MR) experiments. The structures are written with high precision, which has two benefits. First, the real structures behave very similarly to the simulated designs, reducing the component variation; second, this allows for the writing of coils apart from the fairly straightforward solenoidal coils, thereby making complex designs available for MR microcoils.
Mengjia He, Neil MacKinnon, Dominique Buyens, Burkhard Luy, and Jan G. Korvink
Magn. Reson., 6, 173–181, https://doi.org/10.5194/mr-6-173-2025, https://doi.org/10.5194/mr-6-173-2025, 2025
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Parallel NMR (nuclear magnetic resonance) detection enhances measurement throughput for high-throughput screening. However, local gradients in parallel detectors cause field spillover in adjacent channels, leading to spin dephasing and signal loss. This study introduces a compensation scheme using optimized pulses to mitigate gradient-induced field inhomogeneity through coherence locking. The proposed approach offers an effective solution for NMR probes with parallel, independently switchable gradient coils.
Jan Korvink
Magn. Reson. Discuss., https://doi.org/10.5194/mr-2022-24, https://doi.org/10.5194/mr-2022-24, 2023
Publication in MR not foreseen
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The magic angle spinning (MAS) technique of solid state NMR requires samples to be rapidly rotated within a magnetic field. The rotation rate speed record is 150 kHz, or 9 million RPM, and hence MAS turbines hold the world rotation speed record for extended objects. The containers holding the samples are made of the strongest materials known, to be able to withstand the excessive centrifugal forces. To overcome the speed limit, this paper delineates a way to do so using an optical tweezers setup
Neil MacKinnon, Mehrdad Alinaghian, Pedro Silva, Thomas Gloge, Burkhard Luy, Mazin Jouda, and Jan G. Korvink
Magn. Reson., 2, 835–842, https://doi.org/10.5194/mr-2-835-2021, https://doi.org/10.5194/mr-2-835-2021, 2021
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To increase experimental efficiency, information can be encoded in parallel by taking advantage of highly resolved NMR spectra. Here we demonstrate parallel encoding of optimal diffusion parameters by selectively using a resonance for each molecule in the sample. This yields a factor of n decrease in experimental time since n experiments can be encoded into a single measurement. This principle can be extended to additional experimental parameters as a means to further improve measurement time.
Pedro Freire Silva, Mazin Jouda, and Jan G. Korvink
Magn. Reson., 2, 607–617, https://doi.org/10.5194/mr-2-607-2021, https://doi.org/10.5194/mr-2-607-2021, 2021
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We use the theory of magnetostatic reciprocity to compute manufacturable solutions of complex magnet geometries, establishing a quantitative metric for the placement and subsequent orientation of discrete pieces of permanent magnetic material. This leads to self-assembled micro-magnets, adjustable magnetic arrays, and an unbounded magnetic field intensity in a small volume, despite realistic modelling of complex material behaviours.
Mazin Jouda, Saraí M. Torres Delgado, Mehrdad Alinaghian Jouzdani, Dario Mager, and Jan G. Korvink
Magn. Reson., 1, 105–113, https://doi.org/10.5194/mr-1-105-2020, https://doi.org/10.5194/mr-1-105-2020, 2020
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We have assembled a few off-the-shelf electronic chips and a popular Arduino Uno microcomputer board in an automatic system that performs so-called tuning and matching of an arbitrary NMR probe head at very low cost. This removes the tedium of doing the job by hand, the bane of many NMR analysts. It also brings accuracy and repeatability into the process, which is so necessary for high throughput analysis or when working with low-field permanent magnesystems with excessive magnetic field drift.
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Short summary
Magnetic resonance detectors require a high degree of precision to be useful. Their design must e.g. carefully weigh field strength and field homogeneity to find the best compromise. Here we show that inverse computational design is a viable method to find such a
trade-off. Apart from the electromagnetic field solution, the simulation program also determines the boundary between insulating and conducting material and moves the material boundaries around until the compromise is best satisfied.
Magnetic resonance detectors require a high degree of precision to be useful. Their design must...