Editing SQUID (section)

===Proposed uses===
A potential military application exists for use in [[anti-submarine warfare]] as a [[magnetic anomaly detector]] (MAD) fitted to [[maritime patrol aircraft]].<ref>{{cite web|url=http://www.aip.org/tip/INPHFA/vol-4/iss-2/p20.pdf |title=SQUID Sensors Penetrate New Markets |first=Jennifer |last=Ouellette |page=22 |publisher=The Industrial Physicist |url-status=dead |archive-url=https://web.archive.org/web/20080518032905/http://aip.org/tip/INPHFA/vol-4/iss-2/p20.pdf |archive-date=18 May 2008 }}</ref>

SQUIDs are used in [[superparamagnetic relaxometry]] (SPMR), a technology that utilizes the high magnetic field sensitivity of SQUID sensors and the superparamagnetic properties of magnetite [[nanoparticle]]s.<ref>{{Cite journal|last1=Flynn|first1=E R|last2=Bryant|first2=H C|title=A biomagnetic system for in vivo cancer imaging|journal=Physics in Medicine and Biology|volume=50|issue=6|pages=1273–1293|doi=10.1088/0031-9155/50/6/016|pmc=2041897|pmid=15798322|bibcode=2005PMB....50.1273F|year=2005}}</ref><ref>{{Cite journal|last1=De Haro|first1=Leyma P.|last2=Karaulanov|first2=Todor|last3=Vreeland|first3=Erika C.|last4=Anderson|first4=Bill|last5=Hathaway|first5=Helen J.|last6=Huber|first6=Dale L.|last7=Matlashov|first7=Andrei N.|last8=Nettles|first8=Christopher P.|last9=Price|first9=Andrew D.|date=2015-10-01|title=Magnetic relaxometry as applied to sensitive cancer detection and localization|journal= Biomedical Engineering / Biomedizinische Technik|volume=60|issue=5|pages=445–455|doi=10.1515/bmt-2015-0053|pmid=26035107|osti=1227725|s2cid=13867059|issn=1862-278X|doi-access=free}}</ref> These nanoparticles are paramagnetic; they have no magnetic moment until exposed to an external field where they become ferromagnetic. After removal of the magnetizing field, the nanoparticles decay from a ferromagnetic state to a paramagnetic state, with a time constant that depends upon the particle size and whether they are bound to an external surface. Measurement of the decaying magnetic field by SQUID sensors is used to detect and localize the nanoparticles. Applications for SPMR may include cancer detection.<ref>{{Cite journal|last1=Hathaway|first1=Helen J.|last2=Butler|first2=Kimberly S.|last3=Adolphi|first3=Natalie L.|last4=Lovato|first4=Debbie M.|last5=Belfon|first5=Robert|last6=Fegan|first6=Danielle|last7=Monson|first7=Todd C.|last8=Trujillo|first8=Jason E.|last9=Tessier|first9=Trace E.|date=2011-01-01|title=Detection of breast cancer cells using targeted magnetic nanoparticles and ultra-sensitive magnetic field sensors|journal=Breast Cancer Research|volume=13|issue=5|pages=R108|doi=10.1186/bcr3050|issn=1465-542X|pmc=3262221|pmid=22035507 |doi-access=free }}</ref>