13.高温in-situ T_1-SPRITEイメージングによる石炭軟化溶融過程の研究

概要

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Recent modified SPI, single-point ramped imaging with T_1, enhancement (SPRITE), consist of a ramped phase encode gradient in the primary phase encode direction and conventional phase encode gradients in the other directions. The use of a ramped phase gradient permits imaging with greater speed and with lower dB/dt, which is minimizes gradient vibration with compared with SPI. At the same time, a great time improvement is achieved with sample where T_1 relaxation times are on the order of the gradient rise time. Magnetization preparation is easily incorporated into the SPRITE sequence by sampling a single k-space point after each magnetization filter application. Balcom et al. have demonstrated that magnetization preparation permits accurate T_2 and T_1 mapping of samples with short relaxation times. In this paper, we at first are demonstrating 3D-SPRITE which has shown to be successful for studying short relaxation time systems and which is free from distortions due to susceptibility variations for coals with high resolution at a frequency of 400MHz. The results obtained were discussed in relation to the three dimensional distribution of mobile component for 2 kinds of coal. At the same time, inversion recovery preparation experiments (T_1 mapping), T_2 mapping based on SPRITE methods are presented in order to clarify the chemical heterogeneity of coals.
一般社団法人日本エネルギー学会の論文
2000-09-28