Isotope tagging of Ammonium Nitrate.

[pony]

Im not sure if any of you have already come across this, but there doesnt seem to be anything on the forums, anyway its is about the chemical marking of batches of AN with Nitrogen or Hydrogen isotopes. I think this is only occuring in the US, and maybe Australia to keep tabs on exactly where each batch of AN is going.
What it means to those of you that use it:
If you accedently damage anything, or hurt anyone with an explosive and flee the scene, the police can get the residue from the device/charge and deduce exactly where it was bought from and when. The isotopes will be added in parts per billion, so theoretically the government could keep track of 1 billion batches or ammonium nitrate, and after detonation the isotopes can be found up to 5km down wind of the scene.
Another thing is microscopic barcodes, that can identify up to 37 million batches of AN, they are made of plastic so there migh be a way of removing them. (derived from Newscientist)
Its silly though because if you get 2 bags of AN from 2 differant suppliers, and mix them up WELL then all possibilities of tracing you should be wiped.

I doubt if this chemical marking would ever come into force, but it is getting pushed even more into question by terrorists intent on killing people with it.
I never have done, or will, use AN and im in the UK so this will not affect me, but those of you from the US/Oz may want to keep an eye on things, even better use you explosives very responsibly to avoid any chance that this tagging may work against you.

[Zeitgeist]

Wouldn't it cost a ridicuculous amount, to make AN with certain isotopic ratios.
It would have to be impractical.

[vulture]

Not really, as ammoniumnitrate from different sources will already have slight variations in isotope content.

Just make sure you detonate your stuff near farm land or mix it up like pony suggested. Microwave treatment might work too, because it seems to increase the decay of certain isotopes.

[Marvin]

Microwave treatment will do nothing to isotopic ratios and will not speed up or slow down decay rates. Not to mention that putting ammonium nitrate in the microwave has to rank as the dumbest idea Ive heard this week if not the least safe. I'll put this one down to too much caffiene vulture. Hydrogen and nitrogen tagging would have to be done with stable isotopes anyway. None of the radioisotopes would last long enough this end of the periodic table to be remotly useful.

Simply testing all the batches for isotopic content and recording this would not be feasable, so I would strongly suspect this is a pipe dream and/or scarecrow.

Altering by PPB amounts and detecting nitrogen or hydrogen isotopes after detonation isnt feasable either, as contamination with the nitrogen and water in the air would alter the result by such large amounts.

[vulture]

http://sti.srs.gov/fulltext/ms9900762/ms9900762.html

[shady mutha]

According to tonights 7:30 report AN has been pulled off the market.
Incitec the company that makes AN says they have a replacement ready to go.
I am guessing the AN age has come to a end.
Damn! Good and cheap and fun.. :mad: :rolleyes:

[Bert]

According to tonights 7:30 report AN has been pulled off the market.


Ha ha... Australia is going to go back to cow poo poo for agricultural Nitrogen? Bullshit! Ammonium nitrate is the largest product of the fertilizer industry, there IS no replacement in the works. They may require paperwork for purchase, perhaps.

The whole taggant thing is not happening. The sheer quantity of EX used in the world makes this impossible, even if the taggant technology was workable (which it isn't). The taggants have to be durable and dispersable- The whole country would be so contaminated with taggants after a couple of years that no useful information would be presented by the soup of taggant covering everything.

This is one of those things that comes around in the press every couple of years and then goes away. Same as taggants in smokeless powder-

[Zeitgeist]

They have a replacement to go? What, AN blended with chalk? Anhydrous NH3? Oh no, they'll make meth with that

Maybe they will just restrict sale to people with Turbans and AK-47's

[Hang-Man]

Those crazy Australians will just ban AN anyway, despite the repercussions. I seem to remember an incident in 1997 when the Australian government seized 640,000 guns, just to see armed robbery increase 74%, kidnapping 14%, and attempted murder go up 40%. You would think they'd give back the guns after such huge fallout but…….the murder rate went down 11% so...

Maby they will seize 640,000 tonnes of AN, and see the population drop 74% because the people have no food. But they still wont give back the AN because they had a slighly lower rate of people blowing stuff up.

Damn kangaroos. ;)

[Marvin]

vulture, the process that page is describing is incinerating low level waste so that the radioactives remain in the ash, and dont escape in the flue gas. It has nothing to do with trying to reduce the overall activity of the waste.

Bert, I think ZeitGeist is probably on the money for the 'visible' face of fertiliser. The general public sold stuff will probably turn into AN diluted with something inert and end up being sold as nitrochalk etc. AN doesnt have that good a reputation as a fertiliser anyway, it tends to wash out of the soil the first time it rains, its blamed for a lot of the nitrate contamination of lakes. Having said that this is almost certainly a PR stunt by 1 company and probably wont affect farm buyers, ie the people dealing with enough of the stuff to do real damage....

They'll ban water next becuase of the ease you can make hydrogen from it, or for real paranoia they can talk about fusion bombs and the ease deuterium oxide can be seperated from it. Scaremongering will never die, just get furthur away from reality.

[Jacks Complete]

I seriously doubt they will be testing the batches of AN before hand! That would cost a fortune, and even the manufacturers wouldn't be able to afford it. However, I can see them using the isotope ratios to link a certain batch of AN to the suspect. Of course, a decent lawyer will point out that, just like the isotopic and trace analysis of lead done by the FBI, the results don't mean anything since that sample could be a perfect match with a bag from ten years ago, while another sample from the same bag would be different!

However, they found some idiots with half a ton of AN in the UK last week, they charged one today, aged 17. No doubt he confessed so he could get some sleep after being held (awake) as a terrorist for six days. We don't torture any more - we don't need to. Getting AN in small amounts is stupidly hard in the UK, yet you can buy a ton or two easily! I can get off-ticket, legal BP more readily!

[vulture]

This isotope tagging "proof" is going to be shred to pieces bij any decent lawyer. A farmer near you using the same batch would tag half the population of the village, not to mention the food that comes from that field.
You'd have thousands of suspects.

vulture, the process that page is describing is incinerating low level waste so that the radioactives remain in the ash, and dont escape in the flue gas. It has nothing to do with trying to reduce the overall activity of the waste.

Sorry bout that, was a bit too quick with google. Anyways, I'm pretty sure there's a process to speed up radioactive iodine decay with microwave treatment. I believe the process was abandoned because it used more energy than could be produced by the nuclear material.

[matjaz]

Anyways, I'm pretty sure there's a process to speed up radioactive iodine decay with microwave treatment. I believe the process was abandoned because it used more energy than could be produced by the nuclear material.
The only thing that can cause a nonexplosive nuclear transmutation using classical tools currently is a massive laser pulse. Heating the electrons quickly enough to generate multi-MeV X-rays, in turn causing (gamma,n) or (gamma,p) or whatever reactions or to alter internal conversion factor of a decaying nucleus.

(For comparison: peak power densities used are comparable to entire Sun's power squeezed on a 1mm^2 area. No, it's not a typo. It's quite awsome!) A Karlsruhe JRC group does it on a laser system in Great Britain but it's just a few nuclei at a time, not a few grams. :)

Slowly cooking with microwaves is out of question.

----------------------------
Re isotope tagging:

In my opinion, isotope tagging is impossible here. To analyse isotope content at trace levels, the isotopes need to be unstable (radiative) and one than uses high resolution gamma spectroscopy (a germanium detector) to tell them apart. So to measure anything after the thing is dispersed, one should have added a nasty amount of activity into the original explosive. Putting that in a common fertilizer? No way. What is doable is trace-element tagging, though. A masspec or a PIXE system could than see the elemental ratios from the residuals after the blast.

[Jacks Complete]

Not so sure about that. I have read anecdotal evidence that you *can* stimulate radioisotope decay with incident radiation - further to that, there is now a system being developed in the USA using radioisotope storage of massive energy as a way to have nuclear type weapons without fusion or fission. I will post a link, but I think it has been discussed on the boards before - I will check later.

Vulture, the defence lawyer might be a putz. Sadly, in the UK there are too many bad lawyers - I got done because one was shite at his job, and I was proposing legal stragies that he had never thought of, and points of law that he never though of! The worst bit was, when I asked him his legal opinion of one point, and he sat there and said, "Well, you are the expert."! :( Should have sacked him on the spot!
Besides, after 72 hours kept awake without a lawyer or charges (terror legislation, if ever there was some!), the poor sod will have signed a full confession anyway...

[Marvin]

X rays can be used to stimulate decay in certain cases. This is not that surprising, the effect is only the nuclear equivalent of the well understood stimulated fluorescence. Since X ray energies overlap somewhat with gamma energies, and that photo electric effects are well known in the nucleus, this is surprising, but by no means unbelieveable.

Microwaves on the other hand are equivalent to molecular rotation, its so far away from nuclear effects as to be an impossible idea. The only way I can think of microwaves might be 'used' as part of a process, is in a linear accelerator, and this isnt the microwaves doing the transforming at all.

You have to watch out on the web, with the money potential for destroying nuclear waste there are a lot of clueless idiots claiming processes, and possibly patenting processes that simply cant work.

AN is a bulk chemical. If every bag were to be isotopically measured the scale would require massive industries and the cost would render AN uneconomical as a fertiliser. The main problem with hydrogen and nitrogen is they are both present in such large amounts in the air anyway. Gamma spectroscopy is much less sensitive than mass spec anyway - even for fairly short lived radionucleides. If tagging major producers with other elements like say chromium this would help identify the source of a bomb in a different area. I still think the tagging and recording process itself is the least bilieveable primarily for economic reasons. Maybe if it were done in large batches to identify a shortlist of people it would be feasable. If an element were used with a large number of stable isotopes, it would be possible to construct a system where mixing 2 or 3 different batches together would still result in identification of all batch numbers on analysis. Scientifically it is feasable, no manufacturer is going to go to the trouble or expense without a legal requirement though. Maybe seeing what the aussies do will provide insight now there is a public backlash against AN.

[matjaz]

Jack's,
I'd sure like to see that link. I can't think of a good nuclear mechanism that would work like that.

Marvin,
good point. I forgot about using a roentgen to produce X-rays. Silly me, how obvious. :)
I don't agree though that gamma should necessarily be less sensitive than mass spec. 1Bq of a nuclide /kg can routinely be identified with high-resolution gamma spectroscopy. For Cs-137 (30 years) that amounts to 10^9 atoms per kg or 3*10^-13g per kg which is one part in 10^16. Is mass spec sensitivity really better than that? Wow.

[vulture]

You have to watch out on the web, with the money potential for destroying nuclear waste there are a lot of clueless idiots claiming processes, and possibly patenting processes that simply cant work.

True, that's probably also why I can't find anything about it anymore. It has been a bit hyped up a few years ago when I read that.

Still, even if someone got the tagging to work on an industrial scale (which I highly doubt), it still would be pretty shite as forensic evidence.

Tagging the CaCO3 or MgO that comes with it might be a better idea, because the bomber is going to have alot of traces of that on him from the filtering process.

[Marvin]

matjaz,

As I was talking about, the method Jack mentioned is a form of stimulated fluorescence. A specific isotope is manufacturered in a reactor in a metastable state with a relativly long halflife I think 20 years in one case. As is normal with metastable states it emits gamma rays to get to the normal ground state for that nucleide. A specific low energy X ray though, will cause it to decay at once. So illuminating with X rays causes the material to release its energy in the form of much higher energy gamma rays. I think this was in the red mercury thread.

A similar method in electronic excited states is used to detect IR laser light. You get a card with a chemical coating, you 'charge it up' in daylight and in the dark when exposed to IR radiation it emits some of the stored energy as visible light.

While if you have large samples, like 1kg, small levels of radioacitivy can be measured. But at the same concentration, if you only have 1mg of sample, this is only 1uBq total acitivy - totally invisible to gamma spec. Yet it is 1000 atoms of Cs, easily visible to a mass spec, many of which will actually count atoms. My main argument for mass spec over gamma spec, is that for ultimate sensitivity (in terms of total amount, rather than concentration) mass spec detects the atoms in the sample directly, whereas gamma only detects decay events over long periods of time.

[matjaz]

Marvin,
> rays. I think this was in the red mercury thread.

:) Don't know what to think of that thread. Between BS, conspiracy and interesting.

> You get a card with a chemical coating, you 'charge it up' in daylight and
> in the dark when exposed to IR radiation it emits somhhe of the stored
> energy as visible light.

Cute! How does it work? So after charging, we have the the atom sitting atop of a very forbidden transition and then the trigger photon comes... Does it excite the atom to a slightly higher, less stable, state, decaying in turn deep down? Or is it a small stimulated emission first, followed by a deeper one?
In short, is it up-down or down-down?

> 1000 atoms of Cs, easily visible to a mass spec, many of which will
> actually count atoms.

I'm impressed. Thanks for telling me! What is the detector? Silicon strip? Can you tell, say, K-40 from Ca-40?

I agree, then, that gamma spectrometry is the less sensitive one, needed when you need to distinguish between radionuclides and their isobars. Or, of course, when you just have to find about that excited state in Matjazium-144 far from stability ;).

[Jacks Complete]

Looking at the trace elements alone would be a bit pointless. What tends to happen is they look at the ratios of certain elements, say Chromium and Zinc and Boron, and that gives a telltale way to match the batches. To "poison" the check, you need to have a guess at which elements you have to dope up, or go for a shotgun approach, and add a little of everything.

I would suspect that the IR card gets charged to a meta-stable state, then the IR shunts it back down. There are few mechanisms for taking multiple photons are turning them into one higher energy one, and most of those require either high intensity or very precisely matched frequencies, or both.

Mass spectroscopy is ace. (From memory) The detector depends on the mass of the ions as they follow a curved path. The field strength is kept constant, and the velocity is increased (Voltage acceleration) or vice versa. The detector is often a single simple counter that detects the charge change when the ions hit it. Other ones use many detectors, and they can detect smaller amounts, as there is less tracking time. You wil find loads on line about it. The sample goes into a pumped down vacuum chamber, and is sometimes blasted with an electron beam to split the atoms off.

Red Mercury... Does it really exist? Probably not, but hey. If you got a good meta-stable isotope of anything, and did the stimulated release of energy trick on it, you would have a mini nuke, effectively. You just need the equipment to hit it with the right levels of gamma or x-ray, and a target.

*EDIT:*
Did anyone else hear on the main news today, on the BBC, that someone stole three tonnes of AN in Australia? Newsworthy only down under, when there is a terrorist scare!

[Marvin]

I would assume that it would be up, down, as if you take away a NIR photon from the energy of blue/UV visible light there isnt enough energy to still be in the visible range.

I bilieve a lot of mass specs use either electron multipliers or surface barrier detectos, the latter of which I assume is basically an avalanche photodiode with the top cut off. This is mostly speculation on my part. A high rez spectrometer would tell the difference between K-40 and Ca-40, but for general use these would be identical position peaks, though fragmentation paths and relative intensities would be different Id think.

Gamma spectroscopy is very useful for certain jobs, but it really comes into its own when you add neutrons to the equation, so you detect a lot of elements that are normally stable.

Neutron acitivated gamma spectroscopy is very useful when you have a sealed container you dont want to open, like nuclear waste. I would also think if you have a cave and want to know what trace radioactives are in it gamma spectroscopy might be the way to go without trying to shovel multi gram abouts of mineral through a mass spec. Or in positions where its difficuly to get samples of rock and you want a result for a large area, like oil wells.

I dont think elemental tagging would work well Jack. The chemical mechanisms going on the the explosion would distribute different elements in different amounts. If you use ratios of isotopes within each element though, you get a much smaller error, and it is by and large correctable. eg, chromium has about 4 stable isotopes, cadmium has about 8. The relative amounts of Cd or Cr wouldnt matter, and the general scew between the lightest and heaviest isotope should provide a high degree of correction for the isotope effects for a particular sample.

I think much like DNA evidence the first time someone used this in court it would probably be enough to convinct people without any other evidence. Jury blinded with science. As soon as it became used though people would point out all sort of flaws with it, and with the accounting procidures. It might turn out to be a useful way of finding people that might have had something to do with an explosion, and let policework actually convict people. Ultimatly its too expensive to be feasable though. I seem to recall the WTC bombers were caught becuase the ident number of the chassie in the van survived the blast.

I think the funny thing about the stolen AN in australia, is they probably expect it to be highly explosive.

[Jacks Complete]

Marvin, no, I know isotope tagging won't work, I said it earlier on. You just can't get any type of consistency from that sort of volume manufacture, without masses of effort.

The isotope traces in a batch of a ton of lead are totally different between the first pour and the last, so what hope for a 500 ton (continuous process) "batch" of AN?

I can see the Aussie kewl bricking it even now, as the Feds (Does Oz have a federal police force?) hunt him down for $200 worth of AN!

[matjaz]

Marvin,
yes, shovelless gamma spec of soil aka "in-situ" is sensitive to roughly 100m*100m area if you do it 1m above ground. It even works for depth distribution of nuclides in the top 30cm or so. The trick is that higher energy gammas are absorbed less than the soft ones on their way through the soil, so for multi-gamma decays you get information on depth. It can also be done for monoenergetic decays if you do it in several different geometries.