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H bomb test in North Korea

Dear Reader,

It has come to my attention that the North Korean government have claimed that they have detonated a hydrogen bomb. While this is mainly a blog about science rather than my personal moral views I will share with you that fact that I hold the view that this bomb test was ill advised and an act which is morally wrong.

While I might not agree with a lot of the things which some of the hard-line antinuclear activists say and write, but I think many of them will agree with my view that the North Korean government should not waste the money, time or effort on a nuclear bomb program while the quality of life for the normal population is so poor. I have to ask the question of how many hospitals, clean drinking water supplies, schools and rice farms could be constructed and operated using the money required to build a nuclear bomb program.

Now so far it is not clear what did (or did not) occur at about 01:30 UTC this morning, if a nuclear bomb detonation has occurred then it will release radioactivity into the air. The pictures I saw on the news suggested that the bomb was not deep underground, as I could see a mushroom cloud.

If a nuclear bomb has detonated in the air then the radioactivity should be detected by the world wide network of measurement stations which are intended to prevent a bomb test from going unnoticed. These test stations are operated by a UN body. The stations will be likely to detect radioactive xenon, the stations have a series of air monitors which will suck in large volumes of air and then measure the radioactivity in the air.

A range of different counting and concentration methods are used to detect different radionuclides, for the xenon I suspect that they will use some form of gas chromatography to concentrate the xenon and free it from other radioactivity to allow it to be better measured. Some papers have been released in which GC systems for the isolation of xenon from air have been reported.

Another method which I think that they are using is beta/gamma coincidence counting. This is a method which can greatly reduce the effect of background radiation. One method of doing it is to use a scintillation detector which can detect the beta decay which occurs at the same time as a gamma photon is emitted. Using a high purity Ge detector in anticoincidence with a larger sodium iodide detector where the whole system is in coincidence mode with the beta detector then both the Compton scattering effects (nasty splat on the low energy side of the spectrum) and the background could be be suppressed. Add to that a muon detector outside the lead castle for the first three detectors and you could even get rid of some cosmic ray effects. But it is unlikely that a cosmic ray would cause an event in the beta detector or occur by chance at the same time as an event in the high purity Ge detector. But I am sure that it might give some additional improvement in the system.

There is a slight problem, while the popular media want to be the first to report the news the academic world and CTBTO want to get it right rather than report it fast. So the CTBTO may be a little slower than some other bodies to release the data. What they will do is to make a careful review of the data before they explain to us what has happened. Also they are not allowed to hand out data to NGOs, people like me or the general public. They can supply data to a national CRBN body such as FOI in Sweden, then these bodies can use the data. This might irk some people, but in it is a wise precaution against the misuse of data or someone who knows less than they think they do who then misunderstands the data and makes some outlandish statement.

While some of my readers might not like or trust the CRBN bodies, I think that they have fewer vested interests than industry or pressure groups like Greenpeace. One should bear in mind that all the CRBN bodies have access to the data, so unless the large range of diverse states who can get data from CTBTO can all agree to lie to the public (I can not imagine that ever happening) you will get the truth given time for the data to be reviewed and examined in detail. This is as even if one state does not release a truthful statement it is likely that another will release the truth. Already data from the Fukushima event collected by the test ban stations has been discussed by some of the CRBN bodies, so I think that given time the data from this event will be released to the public with an explanation of what the data means.

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