Development of THz electromagnetic wave tomography and its application for evaluation of material deterioration

在这项研究中，一个新的无损评价技术，用于评估材料的劣化利用太赫兹波的传输特性。利用太赫兹时域光谱仪（THz-TDS）对三氧化二铁（Fe_2O_3）和三氧化二铁（Fe_3O_4）的THz波透过率进行了实验研究，并对涂层钢板进行了THz成像。时域THz反射测量数据被用于涂层下腐蚀性材料的3-D成像。利用THz频域反射数据成功地分别识别氧化铁（III）和氧化铁（II）铁（III）涂层下的光谱吸收的基础上。本研究证明了基于THz-TDS的无损评价技术的可行性。

In this study, a new nondestructive evaluation technique for evaluating deterioration of materials was developed utilizing transmission property of THz wave. Experimental studies were carried out for evaluating THz wave transmittance for iron (III) oxide (Fe_2O_3) and iron (II) iron (III) oxide (Fe_3O_4), followed by THz imaging of them for paint coated steel plate using terahertz time-domain spectroscopy (THz-TDS) system. Time-domain THz reflection measurement data were utilized for 3-D imaging of the corrosive materials under coating. Frequency-domain THz reflection data were utilized successfully for separate identification of iron (III) oxide and iron (II) iron (III) oxide under coating based on their spectrum absorption. Feasibility of the nondestructive evaluation technique based on THz-TDS was demonstrated by the present study.