Editing Neutron bomb (section)

==Basic concept==
In a standard thermonuclear design, a small [[fission bomb]] is placed close to a larger mass of thermonuclear fuel, usually lithium deuteride. The two components are then placed within a thick [[hohlraum|radiation case]], usually made from [[uranium]], [[lead]], or steel. The case traps the energy from the fission bomb for a brief period, allowing it to heat and compress the main thermonuclear fuel. The case is normally made of [[depleted uranium]] or [[natural uranium]] metal, because the thermonuclear reactions give off extraordinarily large numbers of high-energy [[neutron]]s that can cause fission reactions in the casing material. These can add considerable energy to the reaction; in a typical design, as much as 50% of the total energy comes from fission events in the casing. For this reason, these weapons are technically known as fission-fusion-fission designs.

In a neutron bomb, the casing material is selected either to be transparent to neutrons or to actively enhance their production. The burst of neutrons created in the thermonuclear reaction is then free to escape the bomb, outpacing the physical explosion. By carefully designing the thermonuclear stage of the weapon, the neutron burst can be maximized while minimizing the blast itself. This makes the lethal radius of the neutron burst greater than that of the explosion itself. Since the neutrons are absorbed or decay rapidly, such a burst over an enemy column would kill the crews but leave the area able to be quickly reoccupied.

Compared to a pure [[fission bomb]] with an identical explosive yield, a neutron bomb would emit about ten times<ref name=Kistiakovsky>{{cite journal |last=Kistiakovsky |first=George |title=The folly of the neutron bomb|journal=Bulletin of the Atomic Scientists |date=Sep 1978 |volume=34 |issue=7 |url=https://books.google.com/books?id=aAoAAAAAMBAJ&pg=PA27 |access-date=11 February 2011 |page=27|doi=10.1080/00963402.1978.11458533 |bibcode=1978BuAtS..34g..25K }}</ref> the amount of neutron radiation. In a fission bomb, at sea level, the total radiation pulse energy which is composed of both [[gamma ray]]s and neutrons is approximately 5% of the entire energy released; in neutron bombs, it would be closer to 40%, with the percentage increase coming from the higher production of neutrons. Furthermore, the neutrons emitted by a neutron bomb have a much higher average energy level (close to 14 M[[Electronvolt|eV]]) than those released during a fission reaction (1–2 MeV).<ref>{{cite book |author=Hafemeister, David W. |title=Physics of societal issues: calculations on national security, environment, and energy |publisher=Springer |year=2007 |isbn=978-0-387-95560-5 |page=18 |url=https://books.google.com/books?id=LT4MSqv9QUIC&pg=PA18}}</ref>

Technically speaking, every low-yield nuclear weapon is a radiation weapon, including non-enhanced variants. All nuclear weapons up to about 10 kilotons in yield have prompt neutron radiation<ref name="fas.org" /> as their furthest-reaching lethal component.  For standard weapons above about 10 kilotons of yield, the lethal blast and thermal effects radius begins to exceed the lethal [[ionizing radiation]] radius.<ref name="Mock up">{{cite web |url=http://www.remm.nlm.gov/RemmMockup_files/radiationlethality.jpg |title=Mock up |publisher=Remm.nlm.gov |access-date=2013-11-30 |url-status=live |archive-url=https://web.archive.org/web/20130607091341/http://www.remm.nlm.gov/RemmMockup_files/radiationlethality.jpg |archive-date=2013-06-07 }}</ref><ref name="johnstonsarchive1">{{cite web |url=http://www.johnstonsarchive.net/nuclear/nukgr1.gif |title=Range of weapons effects |publisher=Johnstonsarchive.net |access-date=2013-11-30 |url-status=live |archive-url=https://web.archive.org/web/20160108000905/http://www.johnstonsarchive.net/nuclear/nukgr1.gif |archive-date=2016-01-08 }}</ref><ref>{{cite web|url=http://www.webofstories.com/play/54981?o=R|title=Weapon designer Robert Christy discussing scaling laws, that is, how injuries from ionizing radiation do not linearly scale in lock step with the range of thermal flash injuries, especially as higher and higher yield nuclear weapons are used|publisher=Webofstories.com|access-date=2013-11-30}}{{Dead link|date=April 2020 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> Enhanced radiation weapons also fall into this same yield range and simply enhance the intensity and range of the neutron dose for a given yield.