NMR IMAGING OF SALT-WATER ICE

Salt-water ice was imaged in a 2 Tesla, horizontal 310 mm bore NMR imaging system at 85 MHz. 50 mm diameter ice cylinders were placed in a temperature-controlled chamber in the NMR system and imaged at temperatures from -20-degrees to 0-degrees-C. Paramagnetic Cu2SO4 at a low concentration was added to the solution, from which one ice sample was crystallized in order to decrease the NMR relaxation time of the entrapped brine in the ice cylinder and thereby speed up image acquisition. The Cu2SO4-spiked sample displayed what appears to be small brine pockets/channels which resemble larger drainage channels seen in thin plates of sea ice. The brine channels/pockets seen by NMR contracted as the temperature decreased. NMR imaging of salt ice appears to be an excellent way to visualize ice structure.