
Movies of Cold War Bomb Tests Hold Nuclear Secrets - curtis
http://www.wired.com/2015/12/nuclear-films/
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matthewmcg
_Trinity and Beyond_ is occasionally available on Netflix and Amazon
streaming. If you catch it, watch it. It's a mesmerizing documentary composed
entirely of restored atomic test footage with spare narration by William
Shatner and an eerie score from the Moscow Symphony Orchestra.

Peter Kuran, the director, worked as a VFX specialist on _The Empire Strikes
Back_ and he's done some other nuke-related documentaries too. He's also
working for the subject of this article.

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darkhorn
[https://youtu.be/XsnL6gmGOZA](https://youtu.be/XsnL6gmGOZA) I think you can
watch it in 3D.

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hyperliner
"100 Suns" is a great book if anybody is interested

[http://www.amazon.com/100-Suns-1945-1962-Michael-
Light/dp/02...](http://www.amazon.com/100-Suns-1945-1962-Michael-
Light/dp/0224064517/)

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anovikov
As far as i remember, there is an easier way to determine bomb yield, which
works at least for bombs which are mostly fission: take a sample from a cloud
using the aircraft or a balloon, determine a ratio of original fissile
material vs some primary fission product, then knowing time passed since
explosion calculate fraction of the material that have reacted, and knowing
ideal yield per kilo and amount of material in the bomb, calculate precise
yield. For boosted fission the fusion portion of yield is insignificant, and
also the fusion is nearly 100% complete, so this is easy to factor in, and in
some cases even OK to ignore.

Of course if most of the yield was fusion this is a different story.

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arethuza
Aren't most bomb designs these days "mostly fission" \- with most of the
energy in most H-bomb designs coming from fission of the secondary tamper by
the neutrons from the fusion stage?

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NamTaf
Yes, that's always been the case as I understand. The fusion stage is to get
the bomb to do its exploding thing before it propels itself apart and thus
just scatters debris everywhere.

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excitom
Don't you have this backwards?

Fusion is the fusing of two hydrogen atoms into a helium atom - the process of
the H-bomb.

Fission is the splitting of a uranium atom which releases neutrons and energy.

The latter reaction produces the energy to start the former reaction.

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davideous
There are bombs where a fission stage ignites a fusion stage which sends
neutrons to start another fission reaction.

From:
[https://en.wikipedia.org/wiki/Thermonuclear_weapon#Summary](https://en.wikipedia.org/wiki/Thermonuclear_weapon#Summary)

"(3) The fusion fuel of the secondary stage may be surrounded by depleted
uranium or natural uranium, whose U-238 is not fissile and cannot sustain a
chain reaction, but which is fissionable when bombarded by the high-energy
neutrons released by fusion in the secondary stage. This process provides
considerable energy yield (as much as half of the total yield in large
devices), but is not considered a tertiary "stage". Tertiary stages are
further fusion stages (see below), which have been only rarely used, and then
only in the most powerful bombs ever made."

