Wednesday, January 6, 2016

Weird nuclear thought of the morning

US Air Force "Constant Phoenix" nuclear surveillance plane
credit: USAF
If you haven't heard the news, the North Korean government claims to have set off a hydrogen bomb. The US government will be attempting to determine the details of the bomb by flying one of their surveillance aircraft to collect those isotopes; it's a WC-135 outfitted with a collection suite for particles. (Is there an analytical suite on-board as well?) The science is run by the Air Force Technical Applications Center - they've hired at C&EN Jobs before.

Anyway, here's my weird thought: that the US government uses aerial surveillance to acquire chemical intelligence about nuclear weapons tests is well known. Does this means that there are North Korean scientists or engineers who attempt to hide/trap those isotopic emissions?

Those of you who understand the business of nuclear weapons, please correct me if I'm nuts. 

12 comments:

  1. Alternately, given that North Korea wants to play brinksmanship-for-profit by making their program look impressive, are there North Korean scientists or engineers attempting to create isotopic emissions to simulate a type of nuke they don't actually have?

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    1. Oooh, an even awesomer weird thought. Well done!

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  2. At one time, they used Tracerlab in Boston for the analysis, if I remember correctly. Last I know, they had built a new radiochemistry lab at AFTAC. (http://www.henselphelps.com/projects/air-force-technical-application-center-aftac-central-headquarters-and-)

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  3. I don't know if there is an official claim by North Korea, but if they did claim to have tested an H-bomb, why would they try to hide the emissions? The only reason I can think of is that to prevent other nations know the composition of the bomb or the amount of radioactive material that's used?

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    1. You might be able to guess the way in which the nuclear material is generated - if it were from somewhere else (not made in NK), you might be able to determine its source.

      Wouldn't this have made a big enough bang (I assume you can't make a small thermonuclear device because you need enough boom to generate fusion) for someone outside NK to have detected?

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    2. Reports are that the seismographic data is consistent with a smaller detonation than you would expect from a thermonuclear weapon. It's comparable in magnitude to their previous three tests. There's a people's congress meeting soon in NK and sometime this week is the little Dear Leaders birthday. The test may be as much for domestic consumption as the world at large. Or maybe they were annoyed that terrorism and Iran were getting all the headlines.

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  4. And isn't the best way to test whether your isotope trapping has worked to announce the bomb very loudly, thereby forcing the US air force to fly over and check? But then you have to assume the US air force is honest about its findings. Conspiracies everywhere!

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  5. Quite likely it may 'just' be a boosted fission device- but I think whatever plume they catch is highly diagnostic as the distribution of daughter isotopes is very specific for the type and size of different bombs. I really don't think there's any way they could fake or mask the isotope signatures as the volume of debris, distribution of particle sizes and amts of the fastest decaying isotopes are too well known and complex to fake (but all of this is outside my area).

    And there's much greater propaganda value in a fusion-esque device than anything else!

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    1. Not much "boost". More like a fission core went off and the H-part didn't ignite....
      The reported estimate of 6 kt yield is much smaller than that of the Indian Shakti-1 (45kt) - the tiniest fusion yield I could find.

      I don't think the Vela incident (a suspect SA-Israeli test in 1979) was confirmed as an actual H-bomb but that one would have been smaller...

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  6. I was also thinking they tried to do a fusion device, got the fission part off and the fusion was a dud, seeing as the seismic data wasn't all that impressive and given the power of other fusion devices. Then they just claim they detonated a fusion device anyway. I guess technically they may have tested a fusion device. Whether or not it worked is another story.

    What isotopes are they looking for anyway? They fuse H to He? Lithium is involved too, maybe? And there'd be U whichever or plutonium involved if there's a fission device.

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    1. I don't know a THING about nuclear decay pathways, but my impression of a thermonuclear device is that it'll feature fast-neutron fission of U-238 - I don't know if this is somehow detectably different from fission of U-235 or Pu-239.

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  7. I don't know how easy it would be to hide the isotopic emissions. The USSR could not do it for their early tests. Also, I concur that it's likely to be a boosted fission device. In spite of the widespread know-how regarding nukes available in the public domain, the devil of the Ulam-Teller mechanism is in its details.

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