Particle accelerators and a Terminator 3 spoiler

In one scene, John Connor and his future wife Kate Brewster are trying to escape from the terminatrix by leading her through a particle accelerator. John powers up the magnetic coils before they run through, and when the fields get to full strength the terminatrix, being made of metal, gets stuck to one of the coils and her polymimetic skin begins to flow into the coil. The pre-post-apocalyptic couple gets away, but the terminatrix manages to escape by sawing through the coil before she gets completely jacked up, and then it’s off to the races again.

So these are my questions:

If the magnetic field strength was enough to pin several hundred pounds (at least) of metal terminatrix, what effect would it have on a human?

If one coil is destroyed, why would the others shut down?

If there were particles being accelerated (I don’t think there were though), what would happen if one or more coils failed?

I once heard the magnets in a particle accelerator could strip the iron out of a human’s blood. I have no idea if that is really true or not (and I only mention it because it is actually something I always wanted a definitive answer to).

That said there are plenty of magnets that could probably pin the terminatrix without having any effect on humans whatsoever. Consider the electromagnets in a junk yard used to pick up cars.

I can only assume that the system, detecting a fault, does an auto shutdown.

The particle would no longer follow the curve of the accelerator and would fly out the side of the accelerator where the magnet failed.

True, but a junked car isn’t trying to get away. The terminatrix’s motor system is pretty powerful, but maybe that’s affected by the magnetic field also.

I figured that part, but what kind of damage would a bunch of uncontained, highly energetic particles do? Would an object struck by these particles become radioactive?

What about the intense magnetic field, and its effect on the components of the terminatrix’ computer brain?

As I type this, the Tevatron at Fermilab has about 10[sup]13[/sup] protons and antiprotons whizzing around at energies of 980 GeV.[sup]1[/sup] Thus, the beam has (9.8E11 eV/particle)(1E13 particles)(1.6E-19 coulombs/e) = 1.6 megajoules of energy. If a magnet fails and the beam is lost, all that energy has to go somewhere.

Of course, I chose the highest energy particle accelerator in the world for the example. Nonetheless, when an accelerator beam is lost, thermal considerations can be as important as radiological ones.

Thermal: Thermal damage (i.e., plain ol’ heating) comes down to the rate at which a particle deposits its energy as it rips through something. That is, does it drop all of its energy in the first centimeter or does it penetrate for a long way, slowly leaving energy behind? This energy deposition rate depends, in turn, on the target material, the particle energy, and the particle type. Since different particle-stopping processes kick in at different energies for different particles, it’s tough to generalize, but some broad rules relevant for higher energies (like those you might find in Terminator III):

  • it’s hard to stop anything neutral (like neutrons)
  • it’s easy to stop electrons
  • it’s not too hard to stop protons

More to the point: a single batch of protons won’t cause too much thermal damage. A single batch of electrons might. A continuous stream of either likely will.

Radiological: Activation (i.e., making something radioactive) will occur if the beam energy is above 1 MeV or so. Below that, you’ll make lot’s of x-rays, but not much permanent will happen. Once you get beyond 100 MeV, activation happens pretty readily, becoming worse (or better, depending on your perspective) with beam energy. High-energy accelerator enclosures are always highly regulated areas because of the residual radioactivity present.

Then there’s the damage to sensitive things, like semiconductors and physicists (as opposed to bulk things like magnets and steel). These things are damaged mostly by ionization, which happens at even the lowest energies.

Also, if superconducting magnets are being used, there’s the risk of “quenching” a magnet. If the beam clips the superconducting material, it can heat a small region up above the critical temperature. The huge currents already in the magnet suddenly see this new bit of resistance, and more heating results. This quickly turns the magnet into a hot, non-superconducting chunk of metal. It can take hours to replenish and cool the liquid helium…

[sup]1[/sup]That’s actually a lie. They lost the “store” a short bit ago:

If anyone knows whether this is true or not, i’d love to know too…

It strikes me as rather unlikely since AFAIK any iron in the blood is part of a compound and hence not (ferro)magnetic.

With a strong enough magnet you do repel flesh (it’s diamagnetic - no I don’t remember what that means)

PS. There was a similar discussion in an X2 thread about Magneto’s effect on humans.

Hey, it just occured to me - if you had a strong enough magnet you might fry yourself due to induced current in the nerves. Bet it’s impossible though.

It means you can levitate frogs. :slight_smile:

Not true. For scale, the strongest fields used in any particle accelerator today are 4.4 tesla. Medical MRIs get up above 1 tesla. I’ve personally had my hand in a 5 tesla field with no ill effects.

How strong does the magnetic field need to be to levitate an animal (in T/kg)? How much do you need to levitate a 67 kg human? I’ve heard that’s been done.

So, basically, even the most powerful magnetic fields have no harmful effects on people. Then why was there all this hysteria about power lines causing leukemia or cell phones causing brain cancer, when the fields emitted by those things are considerably weaker than the magnetic field of the Earth?

There’s a difference: these strong fields are static, delivering no power. Your cell phone can radiate nearly a watt of power.

Disclaimer: this post does not take a stance on the question of whether cell phones or power lines cause cancer. :slight_smile: