Re: NMR combating terrorists

Dan Mills wrote:
> pmlonline@xxxxxxxxx wrote:
>
> > Sam Wormley wrote:
> >> What makes you think that there would be a chance to "NMR" the device
> >> *before* the perpetratoresourcess it off"?
> >
> > You scan the device before it enters the plane.
>
> What is this plane of which you speak? If I was trying to bring a nuke into
> a country covertly, it would probably go by road, rail or sea!
>
> **LOTS** of shipping containers arriving and leaving every day, and the
> ships have well known schedules which they stick to with very good
> reliability, put bomb in container, tag if for the appropriate port and set
> the timer for the scheduled unloading time, job done.

That's the darn job of politicians, not scientists. As a citizen we
can bug the politicians to have scan shipping containers, etc, but the
science community doesn't need to wait around to create or improve
nuclear scanning devices. They can work on getting the containers
scanned and scientists can work on improving the scanning devices.


> Seriously, while there are detectors available (Mostly Neutron counters of
> various sorts (at least for fissile matter)) most freight probably does not
> get examined with this equipment. Furthermore this only addresses fissile
> matter, there are lots of potential dirty bomb isotopes that are not easily
> detectable thru a few inches of steel.

Yes, so then what about NMR. Here's a table that provides NMR data for
various elements.
http://www.york.ac.uk/depts/chem/services/nmr/Periodic_Table_Spin-Quantum-Number-Order.html



> If it comes to that, just buy a freighter and a cargo of ammonium nitrate,
> sail into a inner city harbour and fire a small amount of PETN hidden in
> the cargo. Sure its non nuclear, but a thousand tons of ammonium nitrate
> will make a decent bang!

Yes, but it should be possible to sense it using remote sensing
techniques. I thought NMR was a good choice. Are you aware of ADR
(Atomic Dielectric Resonance)? They've shown that they can detect gold
from quartz that is 10,000 feet below the ground.



> Personally, I worry far more about chemical attack then nuclear, it is just
> so much easier to pull off and the required precursors can be brought in
> the target country, so no border hassle.

They say that the nuclear threat is just as real as the chemical. I
would think the nuclear fall out would be far worse.



> Personally I cannot help but feel that the suicide bombings are self
> limiting (you run out of bombers), and that there are far better places to
> spend the resources in terms of lives saved for a given investment.

I wish that were true, but far from it. The preemptive strikes from my
country, U.S., created a wild fire in the muslim community alone.
Obviously we cannot kill every muslim. Besides it is not 100%
muslims-- even some white Americans get on the terrorists band wagon.
They now hate us more than ever-- with a vengeance!


> The public 'security measures' are basically theatre as far as I can see,
> they do not seem to me to have anything much to do with stopping terrorist
> attacks (not least because they are public and thus open to examination by
> the bad guys), the real work is I hope well out of public view.

I know, and there are many theories flowing around as to why. I sure
would like to know what's really happening. People are saying, "So far
so good. Now big attacks in the U.S. since 911 yet!" Sticking the
head in sand doesn't help though. Unless the science community gets
its b.u.t.t. in gear then it's only time. So far it looks inevitable.


> Just my 5 minute analysis of the situation, which I hope explains why NMR
> scanning is not the answer (think of all those steel shipping containers).

Try ADR then, but why give up on NMR so quickly. That kind of thinking
won't get anything done. You must exhaust all paths otherwise you'll
most likely miss the innovative method. Off the top of my head, it
took 5 seconds to find a work around your supposed brick wall. That
is, use timed pulses. That is how a lot of ground penetrating radar
work. The RF generator sends the signal at t = 0. The RF recording
device starts recording. So you have a steel iron wall in front and
behind it is the nuclear device. Any signal generated from the iron
will arrive at the recording device before the signal generated from
the protons in the nuclear device because the iron is closer to
recording device. That's very basic GPR. The device from Radar World
Ltd has no problem seeing inside any material. Supposedly the same
technology could be used in NMR. Unfortunately Radar World Ltd isn't
revealing any secrets.

Paul

.

Relevant Pages

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