Relaxation-Time Measurement and Imaging in the Earth′s Magnetic-Field

Abstract Investigation of nuclear magnetic relaxation-time imaging and measurement in the earth′s magnetic field using field-cycling spin preparation has been performed. A new pulse technique named magnetization subtraction, which is equivalent to inversion recovery in a strong magnetic field, is introduced. Two new techniques for single-scan measurement of spin-lattice relaxation times in the earth′s magnetic field are described. The results of image weighting with relaxation times in the earth′s magnetic field are presented for the first time.