www.sensornetnews.com

NyTimes: DHS to rip out old detectors and put in new ones

U.S. to Spend Billions More to Alter Security Systems

The articles says,

• problems identified with radiation monitors deployed are prompting an upgrade of these systems.
• false positives and lack of discrimination are causing alarms to be ignored.
• Officials are saying these systems were deployed in a rush post-9/11, perhaps for deterrence, and whether they worked wasn't as high a priority.

Nanotubes for chemical detection

Chemical Detection with a Single-Walled Carbon Nanotube Capacitor
Science Magazine (subscription) - USA
We show that the capacitance of single-walled carbon nanotubes (SWNTs) is highly sensitive to a broad class of chemical vapors and that this transduction ...

Systems engineering, not just better sensors, required to secure buildings from bio/chemical terrorism--says researcher

Fighting terrorism in public spaces: sensing strategies may be an ...
Continuity Central (press releases) - UK
... potential chemical and biological agents to reliably detect, and even with the fastest sensors, some people will become victims before the sensor can respond ....

Nanotechnology may improve chemical detection

Nanoshells enhance sensitivity to chemical detection by factor of ...
Nanotechwire.com (press release) - Philadelphia,PA,USA
... could prove useful for engineers who are trying to probe the chemical processes within small structures such as individual cells, or for the detection of very ...

Insects could be used to detect chemical and biological threats

The DoD is investigating whether insects, weeds, bacteria, and fish can be used to detect biological and chemical toxins: US Military Taps Bugs and Weeds in War on Terror.

This builds on the theme of using dogs to sniff out bombs and  dolphins to find underwater terror threats: Dolphins Valuable to US in Arabian Gulf.

Books on WMD & terrorism

The following books to help in understanding the nature of nuclear, biological, and chemical threats. In particular, they give you a good sense for how what threats are most likely to materialize based on the type of perpretrator (terrorist, nation-state, individual, etc.). These books also expose what the US government is not doing, but could be doing, to protect us against these threats.

1. Nuclear Terrorism is short and reads very easily, sparing lots of detail to give you the big picture. It is written by the founder of the Kennedy School of Government.
2. The Four Faces of Nuclear Terrorism by the Monterey Institute of International Studies is the most recent, most comprehensive, and has an extensive bibliography. It covers policy recommendations and also includes technical details, such as the amount of U or Pu  needed for a improvised nuclear device (IND). The full text is available online as a pdf, so you don't have to buy it unless you prefer the book format.
3. America's Achilles' Heel, written back in 1998 by another Kennedy School professor (Falkenrath) who was subsequently tapped by Tom Ridge for the newly formed Department of Homeland Security, covers a wide variety of possibilities spanning nuclear, biological, and chemical threats.

Another reference is a report on WMD by the Office of Technology Assessment.

U.S. Congress, Office of Technology Assessment. 1993. Proliferation of Weapons of Mass Destruction: Assessing the Risks. OTA-ISC-559.

Active bomb-detection at a distance

High Energy Technologies, a company based in California, offers products to actively detect the chemical composition of substances inside a shielded container . What's interesting is its ability to detect the composition of substances at a distances measured in feet. It is based on their core technology, SuperSenzor, developed in conjunction with US government laboratories. Also see this compairson of their products and press release regarding their appearance at a NATO symposium.

In this "active" scanning technique, high-energy neutrons are shone upon the target, which could contain anything from explosives, drugs, or even anthrax. This induces gamma radiation characteristic of the substance inside the shielded container, which is then used to decipher the chemical composition (stoichiometry). By comparison, other non-invasive techniques such as X-rays only indicate the density of the substance.

Contrast this to passive techniques which, by definition, do not require any sort of active probing such as neutrons. These are not yet commercially available. Steps toward remote bomb detection, analogous to how a trained K-9 dog sniffs them out, have been reported in the research literature. For instance, see the following paper explaining a concept based on MEMS technology in which a tiny vibrating hammer-like traps explosive vapor particles emanating from a nearby bomb and crushes them to induce a mini-explosion which can be detected.

Pinnaduwage, L. A., et. al. 2003. “Explosives: A microsensor for trinitrotoluene vapour,”  Nature. 425: 474, October 2, 2003.

Chemical and Biological Agent Detector Markets $870.5 million in 2004 and projected to reach $2282.1 million in 2010

...according to a report by Frost & Sullivan.

Pranalytica gets $13 million DARPA contract for trace-detection of chemical warfare agents based on lasers

http://www.prnewswire.com/cgi-bin/stories.pl?ACCT=109&STORY=/www/story/09-21-2004/0002255270&EDATE=

RAE Systems Wins $1.3 Million Contract from United States Department of Justice

http://www.tmcnet.com/usubmit/2004/Nov/1089453.htm