MercTech
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quote:
ORIGINAL: Hillwilliam
Organic Peroxides typically contain no Nitrogen and are therefore damnably hard (if not impossible) to detect.
There is actually a simple method developed for the DHS and Border Patrol that readily detects Nitrogen bearing organics even in sealed containers. And, the crazy thing about Organic Peroxides is that they will flag as N-16 under an activation analysis. (Oxygen conversion to Nitrogen with a hefty gamma as it drops back to Oxygen)
Nitrogen activates under a neutron flux and you can detect it via gamma spectroscopy. This concept is decades old and is part of the tech used in well logging to analyze soil strata without having to take lab samples. The engineering problem was to turn an analysis that needs a trained technician to an automated machine that can be monitored by marginally trained security personnel. (not trained in analysis and detection theory and methods. Not challenging the level of tactical training for their mission)
On the Mexican border and in some places on the Canadian border there are gamma spectroscopy detectors on the side with a retractable neutron source in the road bed. A scan is done to detect nitrated compounds in the cargo area of trucks. In some cases, a person might be asked to get out of a passenger vehicle and step inside to have papers reviewed. The passenger vehicle might then be scanned for nitrates.
The bug-a-boo of the system is nitrate fertilizer. Black powder fit for explosives and Triple 13 fertilizer kinda look the same. From what I heard from Border Patrol representatives attending a prototype run of this system in 2006; they planned a protocol that if they got a Nitrogen hit on a commercial vehicle with no nitrates on the shipping papers; that truck would get a detailed hands on search. A hit on a non commercial vehicle would be considered on a case by case basis with the amount of nitrates detected being the decision point. Yeah, every detergent made will show up under a gamma activation analysis but the concentration and localization would be the operators call whether to flag for a hands on search. A 17 pound box of Tide might require a search but a bottle of dish soap would not. (a couple of things used during the prototype test) And, we did enough proof of concept to show you could identify a quart bag of fertilizer hidden in a 55 gallon drum of sugar.
BTW, the half life for radioactive Nitrogen is 17 seconds. No residual radiation to worry about which was one point of using that type of non intrusive analysis.
It would be expensive but such a detection could be added to conveyor belt luggage scanners. But, then TSA would have to hire people that can pass a background check to be a nuclear license holder for more than a low power radiation generating device (baggage x-ray) The legal title is called Radiation Safety Officer - RSO. The person legally responsible for radiation sources. And yes, if you have an x-ray machine, you have to have an RSO. Even the wimpy dentist office models. Such a license is not hard to get but can be a bit time consuming as you have to document attending a class where you learn safe handling techniques and legal requirements. Then you pass an examination and wait for your records to be reviewed and certification issued.
A newer tech that also works to detect chemical hazards is x-ray fluorescence technology. That is currently off the shelf tech but does require licensed operators. (You don't need a license to operate a sealed conveyor belt x-ray machine but a gun type you could point at a person; yeah you need a license.)
https://www.thermofisher.com/us/en/home/industrial/spectroscopy-elemental-isotope-analysis/spectroscopy-elemental-isotope-analysis-learning-center/elemental-analysis-information/xrf-technology.html
The tricky part of the off the shelf units is that you have to identify compounds by relative ratios of component elements. No one has paid to have an automatic database to do so yet. I can personally attest that these are a wonderful method to identify arsenic, lead, uranium, radium, and even asbestos in a survey for remediation of hazards.
A U.S. specific gripe: Why does TSA insist that walk through bomb detectors aren't feasible when the NRC has mandated them for access to commercial nuclear facilities since 1992? Could it be that TSA doesn't trust their people to be able to tell the difference in the chap that spilled gasoline on his show while filling the car from the terrorist that stayed up late building pipe bombs in the kitchen?
(Yes, I've been held up at security because I got diesel on my pants leg when the filler pipe burped back. Had to wait for the watch captain to get done with turnover meeting to get permission to proceed with an explicable alarm.)
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