Magnetic Lenz lenses improve the limit-of-detection in nuclear magnetic resonance
Peer reviewed, Journal article
Published version
Permanent lenke
https://hdl.handle.net/11250/3042455Utgivelsesdato
2017Metadata
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Originalversjon
10.1371/journal.pone.0182779Sammendrag
A high NMR detection sensitivity is indispensable when dealing with mass and volume-limited samples, or whenever a high spatial resolution is required. The use of miniaturised RF coils is a proven way to increase sensitivity, but situations may arise where space restric- tions could prevent the use of a small resonant coil, e.g., in the interior of the smallest practi- cable micro-coils. We present the use of magnetic lenses, denoted as Lenz lenses due to their working principle, to focus the magnetic flux of an RF coil into a smaller volume and thereby locally enhance the sensitivity of the NMR experiment—at the expense of the total sensitive volume. Besides focusing, such lenses facilitate re-guiding or re-shaping of magnetic fields much like optical lenses do with light beams. For the first time we experimentally demonstrate the use of Lenz lenses in magnetic resonance and provide a compact mathematical description of the working principle. Through simulations we show that optimal arrangements can be found.