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LANL pulsed magnet smashes the 100 Tesla magnetic pulse barrier

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March 26, 2012

The 1.2 gigawatt motor-generator system which powers the outer coils on the LANL 100 Tesla...

The 1.2 gigawatt motor-generator system which powers the outer coils on the LANL 100 Tesla pulsed magnet

Image Gallery (5 images)

Round performance numbers aren't necessarily important milestones, but they do exude an undeniable aura of accomplishment. This was the case when researchers at Los Alamos National Laboratory (LANL) used their largest pulsed magnet to crack the 100 Tesla mark (roughly 2 million times larger than the Earth's magnetic field) by generating a 100.75 Tesla magnetic pulse without damaging the magnet.

Magnetic fields about ten times larger have previously been generated (very briefly) in explosively compressed electromagnets, but the LANL 100 Tesla multi-shot magnet (so named as inspiration for their ultimate goal) delivers a pulse lasting about 15 milliseconds - about 2,000 times longer than its explosively driven brethren.

The LANL Pulsed Field Facility where the LANL 100 Tesla multi-shot magnet is located is part of the National High Magnetic Field Laboratory (NHMFL). The magnet consists of an outer coil set, and a smaller coil inserted into the high field region of the outer coil set. The outer coil set is driven by a 1,200 megawatt motor-generator (in operation, the generator is essentially shorted across the outer coil set), and the smaller inner coil is driven by a 2.6 megajoule capacitor bank. The 9 ton (8,164 kg) magnet coils are immersed in liquid nitrogen to reduce resistive losses and for cooling. Yet the magnet still takes about an hour to cool down following a magnetic pulse.

Top view of the LANL 100 Tesla pulsed magnet in its experimental cryostat
Top view of the LANL 100 Tesla pulsed magnet in its experimental cryostat

High field pulsed magnets have two main enemies - heat and pressure - both of which result from the immense current passing through the magnet coils. In particular, the magnetic pressure acting on the wires of the coil is about four gigapascals, a value much larger than the yield strength of the available conductors. The actual stress of the LANL magnet is about 30% of that value, the reduction resulting from a design that distributes the magnetic stress over a larger volume.

The problem of engineering magnets for such strong magnetic fields was sufficiently obscure that an 80 Tesla pulsed magnet was built to allow testing of the inner coil assembly of the 100 Tesla magnet. Views of these this test magnet before use and after 10 pulses is instructive:

The LANL 80 Tesla pulsed test magnet before and after 10 pulses
The LANL 80 Tesla pulsed test magnet before and after 10 pulses

Eventually, however, the engineering problems were worked out through a combined program of testing and simulation.

Success in generating the hoped-for field strengths is welcome, of course, but the real prize lays in investigating the physics of matter in magnetic fields which were previously only available for a handful of microseconds. Some measurements simply take longer than that, so a whole new regime of physical phenomena can be studied using this magnet.

Some current problems for which high magnetic fields are well suited as an experimental probe include superconductivity and other magnetically induced phase transitions, Fermi surface studies, quantum phase transitions, magnetotransport, and, of course, the hitherto unexpected physics which we always seem to find when looking under a new rock. The physics, chemistry, and material science communities are eagerly awaiting this new view of material phenomena.

The video below captures the world record attempt. The howl associated with the energization of the magnet is the sound of a 1.2 gigawatt motor-generator nearly being stalled out by suddenly being shorted across the magnet coils.

Sources: LANL, LANL Report LA-UR-01-5259 (PDF), IEEE Transactions on Applied Superconductivity (2008)

About the Author
Brian Dodson From an early age Brian wanted to become a scientist. He did, earning a Ph.D. in physics and embarking on an R&D career which has recently broken the 40th anniversary. What he didn't expect was that along the way he would become a patent agent, a rocket scientist, a gourmet cook, a biotech entrepreneur, an opera tenor and a science writer.   All articles by Brian Dodson
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9 Comments

So are we going to get free energy out of this or what???

Leonard Foster Jr
27th March, 2012 @ 09:21 am PDT

This must be what they are using to disrupt the weather patterns around the world. What is the point of this device, how can it be used for the betterment of mankind and why is it so inefficient yet touted as groundbreaking?

Just wondering.

Hmmm...
27th March, 2012 @ 03:48 pm PDT

Does anyone think that this is possibly a bad experiment to be conducting? We live and have evolved on a planet with a natural magnetic field. Why would we want to then create one that for all we know may interfere with the one that protects us from harmful radiation. Love how the facility is located in Mexico.

I guess these people think they know what they are doing (I hope). So many things are done because we can and not because we should, with no consideration for the logical implications of what they are doing. I would love someone to logically and simply explain how this is absolutely impossible to cause any problems, and that there is nothing what so ever to be concerned about.

The LHC has nothing on the disastrous possibilities that this experiment conjures up.

Foxy1968
27th March, 2012 @ 06:43 pm PDT

Foxy1968 Los Alamos National Laboratory hasn't been moved it's still located in northern New Mexico, in the USA.

Michael Gene
27th March, 2012 @ 10:02 pm PDT

@Leo Foster - What are you talking about re: disrupting weather patterns? Weather patterns are quite normal as per usual. Even if they were to be being affected, magnetic fields would have zero impact on weather patterns as;

A. Neither water nor air are magnetic

B. Unless it somehow manages to stop the earth's rotation (which is basically impossible aside from something like a major, major asteroid impact) meteorological currents will not be affected either.

However, I may have misunderstood you and I'm happy to change my stance :)

@Foxy I imagine the experiment is conducted at Los Alamos because (to my understanding) it is quite remote. As it is a ridiculously strong magnetic field being pulsed it would likely cause huge interference with radio and satellite communications. Again, I could be wrong.

As well as that, while 100T may sound like a lot and it is, obviously, the 100T is only generated in a very concentrated volume of space and I imagine significantly less magnetic force would escape from the testing area as opposed to the Earth's magnetic field which is quite strong and spread over a huge volume. I would wager that regardless of this magnet's apparent strength, a magnet of several magnitudes more strength would be required to even start affecting the earth's magnetic field detrimentally.

Johl Brown
27th March, 2012 @ 11:48 pm PDT

Wonder what sort of a head rush you would get it you were stuck inside it when it went off?

Would you get an EMP that would enable you to see god? Would you become god, or would your magnetic or paramagnetic particles simply spray forth as you detonated into a mist of red wetness?

Mr Stiffy
30th March, 2012 @ 09:45 pm PDT

I am not into scientific cruelty etc.. but I would just have to stick everything I could ever think of, into this device - just to see what happened to it.

From live rats, to circuit boards, to aerosol cans, hard drives, boxes of welding rods, amplifier valves, graphite pencils, plasma generators, nests of wasps, digital and mechanical watches, desk top printers, gold fish in a fish tank, boxes of rare earth magnets.....

Car axles, crank shafts, Gas cylinders - both full and empty, car batteries, premixed thermite, bags and disks of powdered iron oxide (FEO3), molten iron, old guitar pickups etc.

How well could the energy release be used to crush coins? or coke cans?

I have GOT to try this thing out.

Mr Stiffy
1st April, 2012 @ 08:13 am PDT

You are all so silly. It's meant to be a prototype weapon that will knock out eletronic devices. Next phase is focus and range issues,

Charles Griffith
13th April, 2012 @ 01:52 pm PDT

Hmm i wonder if we could create a much smaller stable field used to protect space stations and possibly moon or mars bases at some point.

Leonvios
17th April, 2012 @ 07:49 pm PDT
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