Study, Design and Optimization of Micro Coil for NMR Applications

Abstract: Nuclear Magnetic Resonance (NMR) has emerged as a powerful tool for the iden-tification and quantification of substances. A critical component within the NMRapparatus is the radio frequency coil, which determines to some extent the sen-sitivity of the NMR device. This research delves into the intricate design andoptimization of the radio frequency(RF) coil, primarily focusing on its dual func-tionality: transmission and reception. As a transmitter, the RF coil emits pulses,initiating a state transition in nuclear spins; as a receiver, it captures energy re-leased when samples revert to their original states. The quality and architectureof the RF coil are paramount, directly influencing the Signal-to-Noise Ratio (SNR)which is proportional to performance factor. The study is based on a 0.5 Tesla ex-ternal magnetic field and uses a frequency of 21.3 MHz, adopting a planar spiralcoil structure. As the simulation result, the best performance factor always showswhen the number of turns is 2 and the spacing between trace is 0.1mm, for thewidth, the performance factor attains its maximum value as the width approachesits geometrical limit, but it does not fully reach this limit. The thesis underscoresthe need for the RF coil to be highly sensitive to specific nuclear magnetic res-onance frequencies, paving the way for advancements in portable NMR devicetechnologies.iii