Editing Nuclear isomer (section)

==Applications==
[[Hafnium]]<ref>{{cite web
| author     = David Hambling
| title      = Gamma-ray weapons
| url        = http://www.eurekalert.org/pub_releases/2003-08/ns-gw081303.php
| publisher  = New Scientist
| website       = Reuters EurekAlert
| date       = 16 August 2003
| access-date = 12 December 2010
}}</ref><ref>{{cite magazine
| author     = Jeff Hecht
| title      = A perverse military strategy
| url        = https://www.newscientist.com/article/mg19025562.200-a-perverse-military-strategy.html
| magazine  = New Scientist
| date       = 19 June 2006
| access-date = 12 December 2010
}}</ref> isomers (mainly <sup>178m2</sup>Hf) have been considered as weapons that could be used to circumvent the [[Nuclear Non-Proliferation Treaty]], since it is claimed that they can be [[induced gamma emission|induced to emit very strong gamma radiation]]. This claim is generally discounted.<ref name="superbombdispute">{{cite web |last1=Davidson |first1=Seay |title=Superbomb Ignites Science Dispute |url=http://www.veteransforpeace.org/Superbomb_ignites_092903.htm |url-status=bot: unknown |archive-url=https://web.archive.org/web/20050510062612/http://www.veteransforpeace.org/Superbomb_ignites_092903.htm |archive-date=10 May 2005}}</ref> [[DARPA]] had a program to investigate this use of both nuclear isomers.<ref>
{{cite news
 | author=S. Weinberger
 | title=Scary things come in small packages
 | url=https://www.washingtonpost.com/ac2/wp-dyn?pagename=article&contentId=A22099-2004Mar24&notFound=true
 | archive-url=https://web.archive.org/web/20110823054905/http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&contentId=A22099-2004Mar24&notFound=true
 | url-status=dead
 | archive-date=23 August 2011
 | newspaper=[[Washington Post]]
 | date=28 March 2004
}}</ref> The potential to trigger an abrupt release of energy from nuclear isotopes, a prerequisite to their use in such weapons, is disputed. Nonetheless a 12-member Hafnium Isomer Production Panel (HIPP) was created in 2003 to assess means of mass-producing the isotope.<ref>{{cite news |url=http://www.commondreams.org/headlines03/0928-07.htm |title=Superbomb ignites science dispute |date=2003-09-28 |newspaper=San Francisco Chronicle |url-status=dead |archive-url=https://web.archive.org/web/20120615015157/http://www.commondreams.org/headlines03/0928-07.htm |archive-date=15 June 2012}}</ref>

[[Technetium]] isomers [[Tc-99m|{{nuclide|Tc|99|m}}]] (with a half-life of 6.01&nbsp;hours) and {{nuclide|Tc|95|m}} (with a half-life of 61&nbsp;days) are used in [[Technetium#Nuclear medicine and biology|medical]] and [[Technetium#Industrial and chemical|industrial]] applications.

===Nuclear batteries===
[[File:Lutetium nuclear isomer energy levels.gif|thumb|upright=2|Nuclear decay pathways for the conversion of lutetium-177<sup>m</sup> to hafnium-177]]
[[Nuclear battery|Nuclear batteries]] use small amounts (milligrams and [[Curie (unit)|microcuries]]) of radioisotopes with high energy densities. In one betavoltaic device design, radioactive material sits atop a device with adjacent layers of [[Extrinsic semiconductor#The two types of semiconductor|P-type and N-type]] [[silicon]]. Ionizing radiation directly penetrates the junction and creates [[electron–hole pair]]s. Nuclear isomers could replace other isotopes, and with further development, it may be possible to turn them on and off by triggering decay as needed. Current candidates for such use include [[silver-108|<sup>108</sup>Ag]], [[holmium-166|<sup>166</sup>Ho]], [[Lutetium-177|<sup>177</sup>Lu]], and [[americium-242|<sup>242</sup>Am]].  As of 2004, the only successfully triggered isomer was [[Tantalum-180m|<sup>180m</sup>Ta]], which required more photon energy to trigger than was released.<ref name=Litz04 />

An isotope such as <sup>177</sup>Lu releases gamma rays by decay through a series of internal energy levels within the nucleus, and it is thought that by learning the triggering cross sections with sufficient accuracy, it may be possible to create energy stores that are 10<sup>6</sup> times more concentrated than [[high explosive]] or other traditional chemical energy storage.<ref name=Litz04>{{cite web |url=http://apps.dtic.mil/dtic/tr/fulltext/u2/a433348.pdf |archive-url=https://web.archive.org/web/20160304042920/http://www.dtic.mil/dtic/tr/fulltext/u2/a433348.pdf |url-status=live |archive-date=4 March 2016 |title=Controlled extraction of energy from nuclear isomers |author1=M. S. Litz |author2=G. Merkel |name-list-style=amp |date=December 2004}}</ref>