A portable, submersible, MR sensor - The Proteus magnet

This paper details the design, fabrication, and testing of a new portable magnet, generically termed the Proteus magnet, that can undertake a wide range of MR measurements. The Proteus magnet is intended for ¹H measurements of liquids and is fully functional when submersed in the sample of interest. The Proteus magnet is fabricated from a pair of low-cost, commercial, NdFeB disk magnets, axially polarized, with their North and South poles aligned. The two N52 NdFeB magnets - 31.75 mm diameter and 6.35 mm thickness were separated by 10 mm. The gap between the magnets is sufficient for a RF shield and transverse rectangular solenoid RF probe. The sensor was evaluated through a series of measurements including bulk CPMG, saturation recovery T₁, self-diffusion, T₁ - T₂, and D - T₂.