Editing Polonium (section)

==Applications==
Polonium-based sources of alpha particles were produced in the former [[Soviet Union]].<ref name="rus1" /> Such sources were applied for measuring the thickness of industrial coatings via attenuation of alpha radiation.<ref>[[#Bagnall|Bagnall]], p. 225</ref>

Because of intense alpha radiation, a one-gram sample of <sup>210</sup>Po will spontaneously heat up to above {{convert|500|C|F}} generating about 140 watts of power. Therefore, <sup>210</sup>Po is used as an atomic heat source to power [[radioisotope thermoelectric generator]]s via [[thermoelectric]] materials.<ref name="anl">{{cite web| url =http://www.ead.anl.gov/pub/doc/polonium.pdf | archive-url =https://web.archive.org/web/20070703021010/http://www.ead.anl.gov/pub/doc/polonium.pdf | archive-date =2007-07-03 |title = Polonium |publisher = Argonne National Laboratory| access-date = 2009-05-05}}</ref><ref name="nbb" /><ref name="g251">[[#Greenwood|Greenwood]], p. 251</ref><ref>{{cite book |url=https://books.google.com/books?id=07TEK_w3A4AC&pg=PA183 |page=183 |last=Hanslmeier |first= Arnold |title= The sun and space weather |publisher=Springer |date=2002 |isbn=978-1-4020-0684-5}}</ref> For example, <sup>210</sup>Po heat sources were used in the [[Lunokhod]] 1 (1970) and Lunokhod 2 (1973) [[Moon]] rovers to keep their internal components warm during the lunar nights, as well as the [[List of Kosmos satellites (1–250)|Kosmos 84]] and 90 satellites (1965).<ref name="rus1">{{cite web |url=http://npc.sarov.ru/issues/sarovbook/section3p11.html |archive-url=https://web.archive.org/web/20070501055529/http://npc.sarov.ru/issues/sarovbook/section3p11.html |archive-date=May 1, 2007 |title=Радиоизотопные источники тепла |url-status=dead |access-date=June 1, 2016}} (in Russian). npc.sarov.ru</ref><ref>{{cite book | first = Andrew | last = Wilson | title = Solar System Log | location = London | publisher = Jane's Publishing Company Ltd | date = 1987 | page = [https://archive.org/details/solarsystemlog00andr/page/64 64] | isbn = 978-0-7106-0444-6 | url = https://archive.org/details/solarsystemlog00andr/page/64 }}</ref>

The alpha particles emitted by polonium can be converted to neutrons using beryllium oxide, at a rate of 93 neutrons per million alpha particles.<ref name="g251" /> Po-BeO mixtures are used as passive [[neutron source]]s with a [[gamma-ray]]-to-[[neutron]] production ratio of 1.13 ± 0.05, lower than for [[nuclear fission]]-based neutron sources.<ref name="gtn">{{cite arXiv |last=Ritter |first=Sebastian |eprint=2111.02774 |title=Comparative Study of Gamma to Neutron Ratios of various (alpha, neutron) Neutron Sources |class=nucl-ex |date= 2021}}</ref> Examples of Po-BeO mixtures or [[alloy]]s used as neutron sources are a [[Urchin (detonator)|neutron trigger or initiator]] for [[nuclear weapon]]s<ref name="nbb">{{cite book| last = Emsley| first =John |title = Nature's Building Blocks| publisher = Oxford University Press| location = New York| date = 2001| pages = 330–332| isbn = 978-0-19-850341-5}}</ref><ref>{{cite book| author = Rhodes, Richard| title = Dark Sun: The Making of the Hydrogen Bomb| publisher = Walker & Company| location = New York| date = 2002| pages = [https://archive.org/details/darksunmakingofh00rhod/page/187 187–188]| isbn = 978-0-684-80400-2| url = https://archive.org/details/darksunmakingofh00rhod/page/187}}</ref> and for inspections of oil wells. About 1500 sources of this type, with an individual activity of {{convert|1850|Ci|TBq|abbr=on}}, had been used annually in the Soviet Union.<ref>[http://www.stringer.ru/publication.mhtml?Part=50&PubID=6767 Красивая версия "самоубийства" Литвиненко вследствие криворукости] (in Russian). stringer.ru (2006-11-26).</ref>

Polonium was also part of brushes or more complex tools that eliminate static charges in photographic plates, [[textile]] mills, paper rolls, sheet plastics, and on substrates (such as automotive) prior to the application of coatings.<ref name="BoiceCohen2014">{{cite journal |last1=Boice |first1=John D. |last2=Cohen |first2=Sarah S. |last3=Mumma |first3=Michael T. |last4=Ellis |first4=Elizabeth Dupree |last5=Cragle |first5=Donna L. |last6=Eckerman |first6=Keith F. |last7=Wallace |first7=Philip W. |last8=Chadda |first8=Bandana |last9=Sonderman |first9=Jennifer S. |last10=Wiggs |first10=Laurie D. |last11=Richter |first11=Bonnie S. |last12=Leggett |first12=Richard W. |title=Mortality Among Mound Workers Exposed to Polonium-210 and Other Sources of Radiation, 1944–1979 |journal=Radiation Research |volume=181 |issue=2 |date=2014 |pages=208–28 |doi=10.1667/RR13395.1 |pmid=24527690 |display-authors=2|bibcode=2014RadR..181..208B |osti=1286690 |s2cid=7350371 }}</ref> Alpha particles emitted by polonium ionize air molecules that neutralize charges on the nearby surfaces.<ref>{{cite web|url=http://www.thermo.com/eThermo/CMA/PDFs/Articles/articlesFile_16929.pdf |title=Static Control for Electronic Balance Systems |access-date=2009-05-05 |url-status=dead |archive-url=https://web.archive.org/web/20131110213624/http://www.thermo.com/eThermo/CMA/PDFs/Articles/articlesFile_16929.pdf |archive-date=November 10, 2013 }}</ref><ref>{{cite news| url =http://news.bbc.co.uk/1/hi/england/1868414.stm |title =BBC News : College breaches radioactive regulations| access-date = 2009-05-05|date=2002-03-12}}</ref> Some anti-static brushes contain up to {{convert|500|uCi|MBq|sigfig=1}} of <sup>210</sup>Po as a source of charged particles for neutralizing static electricity.<ref>{{cite web |url = http://www.amstat.com/solutions/staticmaster.html |title = Staticmaster Ionizing Brushes |publisher = AMSTAT Industries |access-date = 2009-05-05 |archive-date = 2009-09-26 |archive-url = https://web.archive.org/web/20090926032436/http://www.amstat.com/solutions/staticmaster.html |url-status = dead }}</ref> In the US, devices with no more than {{convert|500|μCi|MBq|abbr=on}} of (sealed) <sup>210</sup>Po per unit can be bought in any amount under a "general license",<ref>{{cite web| url = https://www.nrc.gov/reading-rm/doc-collections/cfr/part031/full-text.html| title = General domestic licenses for byproduct material| access-date = 2009-05-05}}</ref> which means that a buyer need not be registered by any authorities. Polonium needs to be replaced in these devices nearly every year because of its short half-life; it is also highly radioactive and therefore has been mostly replaced by less dangerous [[beta decay|beta particle]] sources.<ref name="anl" />

Tiny amounts of <sup>210</sup>Po are sometimes used in the laboratory and for teaching purposes—typically of the order of {{convert|4|-|40|kBq|μCi|abbr=on}}, in the form of sealed sources, with the polonium deposited on a substrate or in a resin or polymer matrix—are often exempt from licensing by the NRC and similar authorities as they are not considered hazardous. Small amounts of <sup>210</sup>Po are manufactured for sale to the public in the United States as "needle sources" for laboratory experimentation, and they are retailed by scientific supply companies. The polonium is a layer of plating which in turn is plated with a material such as gold, which allows the [[alpha radiation]] (used in experiments such as cloud chambers) to pass while preventing the polonium from being released and presenting a toxic hazard.{{citation needed|date=February 2023}}

Polonium [[spark plug]]s were marketed by [[Firestone Tire and Rubber Company|Firestone]] from 1940 to 1953. While the amount of radiation from the plugs was minuscule and not a threat to the consumer, the benefits of such plugs quickly diminished after approximately a month because of polonium's short half-life and because buildup on the conductors would block the radiation that improved engine performance. (The premise behind the polonium spark plug, as well as [[Alfred Matthew Hubbard]]'s prototype [[radium]] plug that preceded it, was that the radiation would improve ionization of the fuel in the cylinder and thus allow the motor to fire more quickly and efficiently.)<ref>{{cite web|url=https://www.orau.org/health-physics-museum/collection/consumer/miscellaneous/spark-plugs.html|title=Radioactive spark plugs|publisher=Oak Ridge Associated Universities|date=January 20, 1999|access-date=October 7, 2021}}</ref><ref>{{cite web|url=http://www.utoledo.edu/nsm/ic/elements/polonium.html|first=Cassandra|last=Pittman|title=Polonium|work=The Instrumentation Center|publisher=University of Toledo|date=February 3, 2017|access-date=August 23, 2018}}</ref>