title: Noninvasive mail inspection system with terahertz radiation.
abstract: Using the high penetrability of the terahertz waves and the characteristic absorption spectra in this frequency range, we have built a noninvasive mail inspection system targeting drugs and explosives. The system is composed of two stages; in the first stage, the scattering of a continuous terahertz wave is used for selecting mail that contains concealed powder; in the second stage, the absorption spectrum of the suspicious mail is measured and the material is identified using a terahertz spectrum database. We evaluated the performance and the limits of the inspection system.
authors.affiliation: RIKEN, 519-1399 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi, 980-0845, Japan. hoshina@riken.jp
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Hoshina
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Aya
authors.initials: A
authors.lastname: Hayashi
authors.forename: Chiko
authors.initials: C
authors.lastname: Otani
authors.forename: Kodo
authors.initials: K
authors.lastname: Kawase