Design and Testing of a Square Helmholtz Coil for NMR Applications with Relative Improved B1 Homogeneity

Abstract

In this article, a radiofrequency (RF) coil that can produce a high electromagnetic field homogeneity to be used for Magnetic Resonance Imaging (MRI) applications is pondered. Helmholtz Coils are a special arrangement of loops such that when an electric current is applied to them, the resultant magnetic field generated between the coils is extremely uniform. Coils configured in this way are also used for applying or measuring fields and are useful for experiments and calibration where a known ambient magnetic field is required. Helmholtz coils play an important role to acquire magnetic resonance images with maintaining good magnetic field homogeneity. In this work, a square Helmholtz coil is designed and tested. The main objectives are to calculate the magnetic field provided by the square Helmholtz coils at any point in space and to show that it is uniform. Simulation is one of the most important parts of this work by which mathematical equations are simulated to investigate the axial magnetic field produced by square loops. Also, electrical modeling for Square Helmholtz coils is carried out. Besides this, the square Helmholtz coil is implemented experimentally and the theoretical and practical results are compared.