niobium–titanium
{{Short description|Superconducting alloy of niobium and titanium}}
Niobium–titanium (Nb-Ti) is a ductile alloy of niobium and titanium, used industrially as a type II superconductor wire for superconducting magnets, normally as Nb-Ti fibres in an aluminium or copper matrix.
Its critical temperature is about 10 kelvins.{{cite journal|author=Charifoulline, Z.|title=Residual Resistivity Ratio (RRR) measurements of LHC superconducting NbTi cable strands|journal=IEEE Transactions on Applied Superconductivity|volume=16|issue=2|date=May 2006|pages=1188–1191|doi=10.1109/TASC.2006.873322|bibcode=2006ITAS...16.1188C|s2cid=38953248 |url=https://cds.cern.ch/record/970393}}
The high critical magnetic field and high critical supercurrent density of Nb-Ti was discovered in 1962 at Atomics International by T. G. Berlincourt and R. R. Hake.{{cite journal|author=T. G. Berlincourt and R. R. Hake|title=Pulsed-Magnetic-Field Studies of Superconducting Transition Metal Alloys at High and Low Current Densities|journal=Bull. Am. Phys. Soc. |volume=2 |issue=7 |page=408|year=1962}}{{cite journal|author=T. G. Berlincourt|journal=Cryogenics|volume=27|issue=6|page=283|year=1987|title=Emergence of NbTi as a Supermagnet Material|doi=10.1016/0011-2275(87)90057-9|bibcode=1987Cryo...27..283B|url=https://zenodo.org/record/1253856}} Nb-Ti alloys are notable for their easy workability and affordability, distinguishing them from other superconducting materials.
Nb-Ti alloys have a maximal critical magnetic field of about 15 teslas and, thus, are suitable for fabricating supermagnets capable of generating magnetic fields of up to about 10 teslas. For stronger magnetic fields, higher performance superconductors, such as niobium–tin, are commonly used, but these are more difficult to fabricate and more expensive to produce.
The global superconductivity market was valued at around five billion euros in 2014.{{Cite web |url=http://www.conectus.org/xxmarket.html |title=Conectus - Market |access-date=2015-05-17 |archive-url=https://web.archive.org/web/20140811140649/http://www.conectus.org/xxmarket.html |archive-date=2014-08-11 |url-status=dead }} Magnet resonance imaging (MRI) systems, most of which use Nb-Ti, accounted for about 80% of the total market value.
Notable uses
=Superconducting magnets=
A bubble chamber at Argonne National Laboratory has a 4.8-meter-diameter Nb-Ti magnet, which produces a magnetic field of 1.8 tesla.{{cite web|url=http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/scmag.html|title=Superconducting Magnets|publisher=HyperPhysics|accessdate=4 Jan 2019}}
About 1,000 Nb-Ti SC magnets were used in the 4-mile-long main ring of the Tevatron accelerator at Fermilab.{{cite web |url=http://supercon.lbl.gov/SuperconDocuments/SSC-MAG-81-1986.pdf |title=Survey of High Field Superconducting Material for Accelerator Magnets|author=R. Scanlan|date=May 1986 |accessdate=2011-08-30 |url-status=dead |archiveurl=https://web.archive.org/web/20110830060831/http://supercon.lbl.gov/SuperconDocuments/SSC-MAG-81-1986.pdf |archivedate=2011-08-30 }} The magnets were wound with 50 tons of copper cables, containing 17 tons of Nb-Ti filaments.{{cite web|url=http://lss.fnal.gov/archive/test-tm/0000/fermilab-tm-0763.pdf|title=The Tevatron|year=1978|author=Robert R. Wilson|publisher=Fermilab|accessdate=4 Jan 2019}} They operate at 4.5 K and generate fields of up to 4.5 T.
1999: The Relativistic Heavy Ion Collider uses 1,740 Nb-Ti SC 3.45 T magnets to bend beams in its 3.8 km double storage ring.{{Cite web |url=http://www.bnl.gov/magnets/RHIC/RHIC.asp |title=RHIC |access-date=2009-12-07 |archive-url=https://web.archive.org/web/20110607061944/http://www.bnl.gov/magnets/RHIC/RHIC.asp |archive-date=2011-06-07 |url-status=dead }}
In the Large Hadron Collider particle accelerator, the magnets contain 1,200 tonnes of Nb-Ti cable,{{cite journal|title=Superconductivity: its role, its success and its setbacks in the Large Hadron Collider of CERN|author=Lucio Rossi|journal=Superconductor Science and Technology|date=22 Feb 2010|volume=23|issue=3|page=034001|doi=10.1088/0953-2048/23/3/034001|url=https://cds.cern.ch/record/1235168|bibcode=2010SuScT..23c4001R|s2cid=53063554 }} of which 470 tons are Nb-Ti[https://www.researchgate.net/publication/224055541_Status_of_the_LHC_superconducting_cable_mass_production Status of the LHC superconducting cable mass production 2002] and the rest copper, and they are cooled to 1.9 K to allow the safe operation of fields of up to 8.3 T.
Image:LHC NbTi superconducting wire.jpg
Niobium–titanium superconducting magnet coils (liquid-helium-cooled) were built to be used in the Alpha Magnetic Spectrometer mission at the International Space Station. They were later replaced by non-superconducting magnets.
The experimental fusion reactor ITER uses niobium–titanium for its poloidal field coils. In 2008, a test coil achieved stable operation at 52 kA and 6.4 T.{{cite web |url= http://www.iter.org/proj/itermilestones |title=Milestones in the History of the ITER Project |work=iter.org |year=2011 |quote=The test coil achieves stable operation at 52 kA and 6.4 Tesla.|accessdate=31 March 2011}}
The Wendelstein 7-X stellarator uses Nb-Ti for its magnets, which are cooled to 4 K to create a 3 T field.
The SCMaglev uses Nb-Ti for the magnets onboard trains. A train using the technology currently holds the train speed world record of 603 km/h. It will be deployed for the Chūō Shinkansen, providing passenger service between Tokyo, Nagoya, and Osaka at a planned maximum operating speed of 505 km/h. Construction is underway for the Tokyo–Nagoya segment, with a planned opening date of 2027.{{cite journal |last1=Uno |first1=Mamoru |title=Chuo Shinkansen Project using Superconducting Maglev System |journal=Japan Railway & Transport Review |date=October 2016 |issue=68 |pages=14–25 |url=http://www.ejrcf.or.jp/jrtr/jrtr68/pdf/14-25.pdf |access-date=21 July 2021}}
Gallery
Cross section of preform superconductor cable.jpg |
Cross section of preform superconductor cable 2.jpg |
Cross section of preform superconductor cable 3.jpg |
See also
- Niobium–tin
- Vanadium–gallium, usable up to 18 tesla
Further reading
- [https://fs.magnet.fsu.edu/~lee/superconductor-history_files/Centennial_Supplemental/11_2_Nb-Ti_from_beginnings_to_perfection-fullreferences.pdf Nb-Ti – from beginnings to perfection] – discovery of the best compositions and conductor designs and fabrication methods.
References
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