T-ray technology came out of Bell Laboratories in the mid 90's. My understanding is that it is an imaging system that uses optics and electronics to create a digital photograph that shows the composition of objects. I thought it was for use in medical applications in the beginning. But many NDT techniques have come about from medical research since there is so much money available for research.
Maybe this technology can be used for some material sorting or identification? These rays must not be dangerous like X and gamma rays but might not have the penetration of radiation or ultrasonic waves. Does terahertz mean "a trillion cycles per second"?