Editing Thulium (section)

==Applications==

===Lasers===
[[Holmium]]-[[chromium]]-thulium triple-doped [[yttrium aluminium garnet]] ({{chem2|Ho:Cr:Tm:YAG}}, or {{chem2|Ho,Cr,Tm:YAG}}) is an active laser medium material with high efficiency. It lases at 2080&nbsp;nm in the infrared and is widely used in military applications, medicine, and meteorology. Single-element thulium-doped YAG (Tm:YAG) lasers operate at 2010&nbsp;nm.<ref>{{cite book |page=49|url= https://books.google.com/books?id=8yM4yF_B72QC&pg=PA49 |title= Solid-state laser engineering |author= Koechner, Walter |publisher= Springer |date= 2006 |isbn= 0-387-29094-X}}</ref> The wavelength of thulium-based lasers is very efficient for superficial ablation of tissue, with minimal coagulation depth in air or in water. This makes thulium lasers attractive for laser-based surgery.<ref>{{cite book |page=214 |url=https://books.google.com/books?id=FCDPZ7e0PEgC&pg=PA214 |title= Tunable laser applications |author= Duarte, Frank J. |publisher= CRC Press |date= 2008 |isbn=978-1-4200-6009-6 |author-link= F. J. Duarte}}</ref>

===X-ray source===
Despite its high cost, portable X-ray devices use thulium that has been bombarded with neutrons in a [[nuclear reactor]] to produce the isotope Thulium-170, having a half-life of 128.6 days and five major emission lines of comparable intensity (at 7.4, 51.354, 52.389, 59.4 and 84.253&nbsp;keV). These [[radioactive source]]s have a useful life of about one year, as tools in medical and dental diagnosis, as well as to detect defects in inaccessible mechanical and electronic components. Such sources do not need extensive radiation protection{{snd}}only a small cup of lead.<ref name="appl">{{cite book |page= 32 |url= https://books.google.com/books?id=F0Bte_XhzoAC&pg=PA32 |title= Extractive metallurgy of rare earths |author= Gupta, C. K. |author2= Krishnamurthy, Nagaiyar |name-list-style= amp |publisher= CRC Press |date= 2004 |isbn= 0-415-33340-7}}</ref>
They are among the most popular radiation sources for use in [[industrial radiography]].<ref>{{cite book |url=https://books.google.com/books?id=lOCjakwiRWAC&pg=PA55 |title=Practical Radiography |isbn=978-1-84265-188-9 |last1=Raj |first1=Baldev |last2=Venkataraman |first2=Balu |date=2004|publisher=Alpha Science Int'l }}</ref>
Thulium-170 is gaining popularity as an X-ray source for cancer treatment via [[brachytherapy]] (sealed source radiation therapy).<ref>{{cite journal
|last= Krishnamurthy
|first= Devan
|author2= Vivian Weinberg
|author3= J. Adam M. Cunha
|author4= I-Chow Hsu
|author5= Jean Pouliot
|title= Comparison of high–dose rate prostate brachytherapy dose distributions with iridium-192, ytterbium-169, and thulium-170 sources
|journal= Brachytherapy
|volume= 10
|issue= 6
|pages= 461–465
|date= 2011
|doi= 10.1016/j.brachy.2011.01.012
|pmid= 21397569}}</ref><ref>{{cite book |last1=Ayoub |first1=Amal |chapter=Development of New Radioactive Seeds Tm-170 for Brachytherapy |date=2009 |chapter-url=http://link.springer.com/10.1007/978-3-642-03474-9_1 |title=World Congress on Medical Physics and Biomedical Engineering, September 7 - 12, 2009, Munich, Germany |volume=25/1 |pages=1–4 |editor-last=Dössel |editor-first=Olaf |access-date=2023-04-01 |place=Berlin, Heidelberg |publisher=Springer Berlin Heidelberg |doi=10.1007/978-3-642-03474-9_1 |isbn=978-3-642-03472-5 |last2=Shani |first2=Gad |series=IFMBE Proceedings |editor2-last=Schlegel |editor2-first=Wolfgang C.}}</ref>

===Others===
Thulium has been used in [[high-temperature superconductor]]s similarly to [[yttrium]]. Thulium potentially has use in [[ferrite (magnet)|ferrite]]s, ceramic magnetic materials that are used in [[microwave]] equipment.<ref name="appl" /> Thulium is also similar to [[scandium]] in that it is used in arc lighting for its unusual spectrum, in this case, its green emission lines, which are not covered by other elements.<ref>{{cite book |page= [https://archive.org/details/elementsvisualex0000gray/page/159 159] |url= https://archive.org/details/elementsvisualex0000gray/page/159 |title= The Elements: A Visual Exploration of Every Known Atom In The Universe |author= Gray, Theodore W. |author2= Mann, Nick |name-list-style= amp |publisher= Black Dog & Leventhal Publishers |date= 2009 |isbn= 978-1-57912-814-2 }}</ref> Because thulium [[fluoresce]]s with a blue color when exposed to [[ultraviolet|ultraviolet light]], thulium is put into [[euro]] [[banknotes]] as a measure against [[counterfeit]]ing.<ref name="Photochemistry">{{cite book |url= https://books.google.com/books?id=XAjIWgENf5UC&pg=PA75 |page= 75 |title= Principles and Applications of Photochemistry |isbn= 978-0-470-71013-5 |last1= Wardle |first1= Brian |date= 2009-11-06|publisher= John Wiley & Sons }}</ref> 

The blue fluorescence of Tm-doped calcium sulfate has been used in personal dosimeters for visual monitoring of radiation.<ref name="history" /> Tm-doped halides in which Tm is in its 2+ oxidation state are luminescent materials that are proposed for electric power generating windows based on the principle of a [[luminescent solar concentrator]].<ref name="Richards 2023">{{cite journal | last1=Richards | first1=Bryce S. | last2=Howard | first2=Ian A. | title=Luminescent solar concentrators for building integrated photovoltaics: opportunities and challenges | journal=Energy & Environmental Science | volume=16 | issue=8 | date=2023 | issn=1754-5692 | doi=10.1039/D3EE00331K | pages=3214–3239| doi-access=free | bibcode=2023EnEnS..16.3214R }}</ref>