Field research

[unixronin]

Magnetic field, that is.  "Black gold, Texas ..."  No, want a minute, that's not right.

The ATLAS Barrel Toroid, the world's largest superconducting magnet, has been successfully powered up and tested at CERN's Large Hadron Collider.  After being cooled down to 4 Kelvin over a six-week period, it was gradually powered up over the course of about two months, reaching a peak current of 21,000 amps.

Yeah.  But if that number, which is 500 amps over "nominal field", makes your eyebrows rise, try this one for size:  At that current, the stored magnetic energy in the field was 1.1 GJ.  After being powered off, it took ten days for the field to decay, raising the temperature of the magnet from 4 Kelvin to 53 Kelvin.

The article doesn't state the actual field strength.  But that's one holy hell of a magnetic field.

(Click the thumbnail for some serious "Ooh!  SHINY!")

(Link from mrmeval)

Comments

[smandal.livejournal.com]

The average magnetic field strength is easily calculated:

energy density U = B^2 / 2 \mu_0 = E / V = E / (\pi d^2/4 * l)

B = sqrt(8 E \mu_0 / pi d^2 l)

= 2.3 Tesla

The actual magnetic field strength varies from 1 to 4 Tesla.

For reference, 1.1 GJ is about the same as 250 kg of TNT; this is the yield of a suitcase nuke or an Exocet missile.

Here's a cool brochure in PDF (http://cern.ch/atlas-magnet/info/project/ATLAS_Magnet_Leaflet.pdf).

[unixronin.livejournal.com]

The average magnetic field strength is easily calculated:

energy density U = B^2 / 2 \mu_0 = E / V = E / (\pi d^2/4 * l)

B = sqrt(8 E \mu_0 / pi d^2 l)

= 2.3 Tesla

That's easy for you to say. :) I personally freely admit I don't know how to calculate it.

[ithildae.livejournal.com]

The equations and explanation are in any first year physics book, second half. Given some motivation and the text, you would have no problem with it.

[unixronin.livejournal.com]

I don't doubt knowing where to find the equations would be half the battle. :) I'm just so rusty on my physics ..... :(