What is maximum magnetic field strength of SC magnet

[Astronuc]

Another poster is looking for a 20T magnetic field or better, so I went looking for what has been reported as the maximum field strength for an SC magnetic field to date. However I found some contradicting claims.

Is there a refereeing organization or a reputable source from which to determine the actual maximum field strength so far achieved?

National Research Institute for Metals (NRIM) of the Science and Technology Agency (STA) which had been constructing a high magnetic-field laboratory as a key center for high magnetic-field research succeeded recently in generating a magnetic field of 37.3 teslas (1 tesla = 10,000 gausses) in a steady-state by using a hybrid magnet. This success is expected to contribute to a remarkable progress in such areas as research on materials in high magnetic fields. The highest record sofar had been 36 teslas also attained by NRIM in 1995.

STA TODAY November 1999, http://www.mext.go.jp/english/news/1999/10/s991002.htm

The team’s newest niobium-tin dipole electromagnet reached an unprecedented field-strength of 14.7 Tesla. This is more than 300,000 times the strength of Earth’s magnetic field.

http://www.lbl.gov/Science-Articles/Archive/14-tesla-magnet.html (July 5, 2001)

In August, researchers at the National High Magnetic Field Laboratory's headquarters at FSU announced that they had set a new world record in the power of a special kind of magnet built with superconducting materials.

The device achieved a strength of 25 Tesla (a measurement of magnetic field strength), breaking a 20-Tesla barrier that had stood for more than 15 years. (A single Tesla is 20,000 times the strength of Earth's magnetic field; a small refrigerator magnet is typically one Tesla or less.) Early 2004.

http://www.research.fsu.edu/researchr/fall2003/departments/abstracts.html#super

Well FSU's does beat LBL's, but NRIM's would exceed either. Are there anymore claims out there?

I had thought that 15T was about the max.


For reference -

The strength of the field at the Earth's surface at this time ranges from less than 30 microteslas (0.3 gauss) in an area including most of South America and South Africa to over 60 microteslas (0.6 gauss) around the magnetic poles in northern Canada and south of Australia, and in part of Siberia.

from Wikipedia - http://en.wikipedia.org/wiki/Earth's_magnetic_field. Apparently some take the Earth's field at about 50 $\mu$T.

 

[Astronuc]

Intuitive posted a link to a list of records of "Magnetic Field of the Strongest Magnet".

http://hypertextbook.com/facts/2000/AnnaWoo.shtml

which has a link to NATIONAL HIGH MAGNETIC FIELD LABORATORY - http://nmr.magnet.fsu.edu/facilities/45T_32mm_TLH.htm

NHMFL's 45 Tesla hybrid magnet is the highest continuous magnet field available in the world. The outer superconducting coil produces static field of about 11 Tesla, with the rest of the field being generated by water-cooled resistive insert. Bore size diameter is 32 mm. This magnet was not designed with NMR homogeneity in mind, and its field instability is not to NMR specs. Field stability in resistive magnets is compromised by fluctuations in power supply and in temperature of the cooling water.

In the case of high field pulsed magnets -

A typical non-destructive pulse coil used at the NHMFL consists of about 300 turns of rectangular cross-section wire (2 x 3 millimeters) in ten layers. The bore (the hole at the center of the magnet) for the experiment is usually between 10 and 25 millimeters (mm) and the height of the magnet is about 100 mm.

http://www.magnet.fsu.edu/focus/construction.html

Pulse magnets come in two forms: destructive and non-destructive. Non-destructive pulse magnets can generate a magnet field pulse as high as 70 Tesla. The average life span of a non-destructive magnet is 500 to 800 pulses. Destructive pulse magnets, as their name implies, are violently ripped apart by the massive stress placed on them when they are switched on. To reach field in excess of 100 Tesla researches set up explosives around the magnet that detonate as the magnet is powered. The explosion compresses the magnetic field allowing scientists to attain fields as high as 1,000 Tesla for a split second.

http://www.magnet.fsu.edu/focus/operation.html

 

[ZapperZ]

You are encountering the problem many of us have in deciphering things like this. If you look closely, a lot of these claims are meant for either a particular configuration, or a particular material. This is true, for example, in the Nb-Sn claim. They're not claiming that it is the largest ever magnetic field generated. So things like this can be confusing.

Unfortunately, you've asked this after I've started my vacation, so I do not have access to all the online libraries at work and can't go do a quick check on the highest field so far. But I would guess that continuous 45 Tesla claim would not be too far off. The record for pulse field, I don't know.

Zz.