X-ray wavelengths correspond to both atomic energy levels and interatomic spacings, enabling X-ray fluorescence (XRF) and
X-ray diffraction (XRD) in laboratories. But nonscientists are more likely to be familiar with technology that makes use of
the penetrative power of X-rays, whether in the dentist's chair or in the security line at the airport. Security applications
for X-ray technology now represent a $1.5 billion business, and many of the products go beyond simple imaging to better detect
and identify potential threats.
One of the most advanced uses of X-rays is in computed tomography (CT), which provides three-dimensional images of scanned
items. CT-based security systems are primarily used in aviation for baggage and cargo scanning. Some of these CT systems also
incorporate XRD to better identify explosives or other chemical hazards.
X-ray security market demand by product type for 2009.
Even traditional X-ray imaging systems can offer greater analytical capabilities. Many newer systems offer dual energy analysis,
in which two detectors are used, with a filter between them that transmits only the high-energy X-rays. By comparing the differential
absorption of high- and low-energy X-rays, the system provides better discrimination of low atomic number materials, including
explosives and other organic contraband.
Another method for imaging such materials is by detecting backscattered X-rays. This technology forms the basis of the new
backscatter portals for passenger screening that will likely become a common sight at airports in the near future. Although
privacy issues continue to make backscatter portals controversial, the market for them should more than double in 2010.
Some of the foregoing data were extracted from SDi's market analysis and perspectives report entitled "Chasing Disaster:
Analytical Instrumentation for Security and Related Safety Applications," July 2010. For more information, contact Michael
Tice, VP of Consulting Services, Strategic Directions International, Inc., 6242 Westchester Parkway Suite 100, Los Angeles,
CA 90045, (310) 641-4982, fax: (310) 641-8851, www.strategic-directions.com.