The dissemination of fast-acting chemical agents poses a great threat to public safety. Because authorities will have little time to react in the event of an emergency, it is critical that highly accurate identification methods be used. Also, to avoid the threat of infection, it will be necessary to have instruments that can detect and identify chemical agents at a safe distance. To meet these requirements, a number of standoff (non-contact) detection methods are now being investigated. These include fast Fourier interferometry to detect long wave infrared (LWIR) signatures, thermoluminescence, and laser-induced breakdown spectroscopy (LIBS).

For contact-type sensors, mass spectroscopy has been used as a way to identify chemical agents. In this application, a sample is bombarded with an electron beam that has sufficient energy to break apart the sample into molecules. The positive fragments (cations and radical cations) produced by this process are accelerated in a vacuum through a magnetic field, and then sorted on the basis of mass-to-charge ratios. The detectors used in this type of system are primarily microchannel plates (MCPs) and ion detectors.

In the future, other approaches may be adopted as an alternative to traditional mass spectroscopy and ion mobilization spectroscopy. Some of these methods are surface-enhanced Raman spectroscopy (SERS), near-infrared spectroscopy, and infrared spectroscopy.

• InGaAs linear image sensors: cooled and uncooled InGaAs arrays. Suitable for NIR spectroscopy at wavelengths up to 2.6 microns.
• InGaAs PIN photodiodes: a wide range of high-speed, low-noise detectors for wavelengths up to 2.6 microns.
• Time-of-flight assemblies: microchannel plate assemblies for mass spectroscopy. Available in different active area diameters, channel diameters, and configurations.
• S9972/S9973 series CCDs: front-illuminated CCD image sensors with high infrared sensitivity. Suitable for Raman spectroscopy, SERS.
• R6095 28 mm head-on PMT: spectral response from 300 nm to 650 nm. Low-profile type.
• R5070A 25 mm head-on PMT: spectral response from 300 nm to 900 nm. Includes prismatic window for high NIR sensitivity.
• R1924A 25 mm head-on PMT: spectral response from 300 mm to 650 mm. Low-profile type for scintillation counting.

Please contact us for information on other products which can be used for this application.