China debuts first terahertz scanner for security checks

China has developed its first terahertz (THz) security scanner, which is expected to have broad applications, according to an announcement at a defense industry exhibition on Thursday. China's first terahertz security scanner debuted at the ninth China International Defense Electronics Exhibition. It was independently developed and manufactured by the China Electronics Technology Group Corporation, one of China's defense industry giants. Security scanners of this kind can work without interruption, scanning 500 people per hour, or about one person per second, five times the efficiency of manual checks. The scanners are expected to be put into mass use in 2015 in public places such as airports, train stations, stadiums and foreign embassies. The development will chip away at the United States' monopoly and dominance in the terahertz application market, according to Chinese experts. Terahertz radiation is a kind of electromagnetic radiation with wavelengths between those of infrared rays and microwaves, boasting a strong penetration force without harmful effects. The human body naturally transmits terahertz waves, which can be received by the terahertz body scanner. By contrasting the image projected on the scanner screen with the background image of the human body, security staff can determine if a person is hiding something in their clothes as the object would deflect or hinder the terahertz transmission path. Compared with traditional security check devices, terahertz scanners are much safer and more reliable, said one of the developers. Terahertz scanners can not only detect metal objects but also non-metal materials such as ceramics, powders and liquids. Moreover, terahertz scanners do not require bodily contact with those being examined. The image projected on the screen does not show details of the person being scanned, allowing for protection of privacy.