Titel: “A Compact NMR Device to Detect Zero Quantum Coherences”
Sprecher: Jonathan Rapp, Masterand in der Forschungsgruppe Magnetische Felder von Dr.-Ing. Bernhard Gleich
Datum und Uhrzeit: Dienstag, 19. Mai, 13:00 Uhr
Recent progress in compact nuclear magnetic resonance (NMR) spectroscopy devices demands new solutions to overcome the poor resolution due to field inhomogeneities. Especially for the investigation of molecules the detection of J-couplings is crucial in order to understand the interaction of molecular groups. One way to detect J-couplings despite low resolution is via zero quantum coherences (ZQC) which are quite insensitive to field inhomogeneities. However, for this application a pulsed field gradient is required. The presentation demonstrates a device which is capable of performing NMR measurements including a field gradient. It consists of a single coil, an analogue transceiver board and a field programmable gate array (FPGA) based digital signal processing unit. The device is applied for the detection of J-couplings via ZQCs in n-Butanol. Development and characterization of the transceiver board are explained, and ZQC experiments are presented. The resulting spectra are shown and discussed. Parts of this thesis are published in IEEE Transactions on Instrumentation & Measurement, ”An NMR Probe Head Incorporating Radio Frequency and Direct Current Capabilities to Generate Pulsed Field Gradients”. The paper was written by Andreas Wegemann, Christoph Staat, Jonathan Rapp, Alexandra Heidsieck, Axel Haase and Bernhard Gleich.