4D shimming of Halbach Array Magnet System

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_Spin Echo Limited is an Original Equipment Manufacturer (OEM) of multi-phase flowmeters for use in the transport of hydrogen + natural gas admixtures, carbon capture applications and in convention Oil & Gas production as a means to optimize production yield and environmental performance by lowering the amount of water cut and associated (flare) gas produced.__The company's innovative Nuclear Magnetic Resonance (NMR) flowmeter technology utilizes a low-cost Halbach array magnet system to create an electromagnetic vacuum suitable for NMR measurements to be taken. In order to achieve the required magnetic field (0.12T strength and <1000ppm field error), it is necessary to shim the Halbach array magnet. Shimming is the process of adding small amounts of magnetic material between the magnetic field source and measurement plane to effectively tune the field.__In partnership with ASTUTE, this project will seek to define a new shimming algorithm that will improve upon the existing shimming capabilities employed in Spin Echo's manufacturing process. Improvements to the homogeneity in the magnetic field of the Halbach array will improve meter performance in terms of accuracy and cost to manufacture.__To realise a new shimming algorithm, the project partners will complete numerical analysis, modelling and 3D simulation work using specialized software to define a new arrangement of shims . At present, the shimming algorithm employed in Spin Echo's production process only considers 2 dimensions - shim width and radial location of the shim relative to the magnetic source. This project will consider the addition dimensions of shim length and axial location of the shim relative to the magnetic source.__The project partners believe that this new 4D shim algorithm could lead to significant improvements in the accuracy and manufacturability of the NMR flowmeter. Should the new 4D algorithm achieve field error in the sub 100ppm range, the Halbach array magnet system could also find new applications such as a low-cost MRI scanning for health care purposes or as an energy storage vessel._