Development of a Magnetic Shield for Magnetoencephalography with Optically Pumped Magnetometers

The Optically-Pumped Magnetometer Magnetoencephalography (OPM-MEG) is a noninvasive brain imaging tool that will revolutionize brain science and health delivery. It is used by doctors and researchers in order to observe neural activity within the brain and has helped develop our understanding of epilepsy, speech decoding, and functional connectivity among other subjects of interest. We intend to develop a magnetic shield to perform MEG on animals such as rats and frogs for a relatively cheap price, which will hopefully be expanded to eventual use on human subjects. The shield will have multiple layers in order to achieve a transverse shielding factor of at least 5000, strong enough to make interference from Earth's magnetic field negligible. The shield will have multiple layers, which when sufficiently spaced, the transverse shielding factor is dominated by the product of the shielding factors and a geometric factor between 0 and 1. The MuMETAL layers will be supported by a sonotube and foam fillings. Additionally, multiple segments of the layers will be used in order to emulate an "infinite" cylinder.