In a
news article in Nature yesterday, Declan Butler & Elizabeth Gibney
ask "What kind of bomb did North Korea detonate?"
In order to tell, the hope is that some of the radioactive gasses leaked
from the underground explosion and that prevailing winds will carry them
far enough to be detected for nuclear forensic analysis.
But in order to do so, some of the short-lived isotopes would need to be
measured within the coming days before they decay.
The Preparatory Commission for the Comprehensive
Nuclear-Test-Ban Treaty Organization (CTBTO) maintain a global network
of radiation monitors.
Quote:
Originally Posted by Declan Butler & Elizabeth Gibney, Nature
Although the CTBTO detected xenon two weeks after North Korea’s first test in 2006, it detected none after the country’s 2009 test, and only spotted xenon more than a month after a third nuclear test in 2013. That was too late for useful forensics.
|
Last month, satellite imagery had detected that North Korea has been
excavating a new tunnel at the Punggye-ri nuclear test site.
Article and imagery here -
http://38north.org/2015/12/punggye120215/
In the Nature news story, James Acton, who studies nuclear policy at
the Carnegie Endowment for International Peace in Washington DC,
also says that the seismic event indicates an explosion in the order of
10 kilotonnes - too small for a H-bomb - but speculates, as I had done
earlier, as to whether it might be a boosted fission device employing small
amounts of deuterium and tritium.
Quote:
Originally Posted by Declan Butler & Elizabeth Gibney, Nature
Experts have speculated for years that North Korea might be working on such a device. Boosted devices are smaller yet can be just as powerful as fission bombs, making them more suitable for use in missile warheads. The research involved in developing them is also a step along the way to developing thermonuclear weapons.
|
Quote:
Originally Posted by Declan Butler & Elizabeth Gibney, Nature
And as the radioactive gases are transported through rocks and air, adds the CTBTO’s Martin Kalinowski, some isotopes of xenon become more enriched than others. This can blur the signatures of the original explosion.
Without other sources of intelligence, the chances of reliably determining what kind of nuclear weapon North Korea did detonate are low, he thinks.
|
Nature news story here -
http://www.nature.com/news/what-kind...tonate-1.19132
Richard Stone, in Science, also reports on the test being of low-yield
and speculation of whether it might be a boosted fission device -
http://news.sciencemag.org/asiapacif...ly-have-h-bomb