What else could the LHC accelerate?

[teve]

The LHC accelerates protons and lead ions. Are all the electrons stripped from the lead ions? If so, could lead ions with some electrons still be accelerated? Would there be any reason to?

Could the LHC accelerate alpha particles or other nuclei? Why lead ions over lighter or heaver nuclei?

Do colliding neutrons produce anything that colliding protons only do not? Why not collide alpha particles if neutrons are to be included? I would think that colliding lead ions would produce a larger mess of particles to sort out. Or is it all the same if protons are clumped together or spread out within a bunch (except for neutrons in the mix)? What results come from colliding lead ions that does not come from colliding single protons?

Could the LHC accelerate and collide electrons? If so, to what speed or energy?

 

[bcrowell]

The LHC accelerates protons and lead ions. Are all the electrons stripped from the lead ions? If so, could lead ions with some electrons still be accelerated? Would there be any reason to?

Could the LHC accelerate alpha particles or other nuclei? Why lead ions over lighter or heaver nuclei?

Do colliding neutrons produce anything that colliding protons only do not? Why not collide alpha particles if neutrons are to be included? I would think that colliding lead ions would produce a larger mess of particles to sort out. Or is it all the same if protons are clumped together or spread out within a bunch (except for neutrons in the mix)? What results come from colliding lead ions that does not come from colliding single protons?

Could the LHC accelerate and collide electrons? If so, to what speed or energy?

The binding energies of atomic electrons are on the eV scale, which is negligible compared to the TeV scale of LHC collisions. Any electrons would be irrelevant spectators. The machine will be tuned for a certain charge to mass ratio. Any atoms that were not fully ionized would have the wrong q/m and would not make it through the machine.

The LHC can't collide neutrons. It can only accelerate charged particles.

For the reasons why the LHC can't accelerate electrons, see the last paragraph of this section of this WP article: http://en.wikipedia.org/wiki/Bremstrahlung#Dipole_approximation

Someone more well versed in accelerator-based particle physics might be better suited to answer you question about why intermediate-mass nuclei are not being used. I doubt that it's an accelerator issue.

 

[teve]

I know neutrons can't be accelerated. I meant colliding neutrons when carried along with protons.

 

[teve]

Thanks. I think I can see the issue with charge to mass ratio. Then the next question would be what range of charge to mass ratio for particles can LHC accelerate.

 

[Vanadium 50]

Since protons have the highets charge-to-mass ratio of any nucleus, and Pb is among the lowest (I believe it is the lowest for stable nuclei; if not, it's close), in principle it can accelerate pretty much any stable nucleus.

However, you need a source, and at present the LHC has only two: protons and lead. To accelerate iodine or calcium or something else would mean someone would have to build additional hardware.

 

[teve]

Found this: http://www.symmetrymagazine.org/breaking/2010/11/05/the-skinny-on-the-lhcs-heavy-ions/

Apparently heavy ions allow quark-gluon plasma to be studied. The lead used is the heaviest stable lead isotope, 208, purified at a dollar per milligram. A few grams is probably a lifetime supply.

I am guessing lead 208 is used since it has the most protons and neutrons lumped together while being stable. Is there any reason to go with anything less?

I am guessing electrons could not be accelerated because they would have to be fed in the opposite direction at the various stages of acceleration even if charge to mass ratio was not an issue.

 

[bcrowell]

Since protons have the highets charge-to-mass ratio of any nucleus, and Pb is among the lowest (I believe it is the lowest for stable nuclei; if not, it's close), in principle it can accelerate pretty much any stable nucleus.

However, you need a source, and at present the LHC has only two: protons and lead. To accelerate iodine or calcium or something else would mean someone would have to build additional hardware.

I assume it's a positive ion source. I believe positive ion sources are really not all that specialized. You can pretty much feed in anything you like. (Negative ion sources are different. Some negative ions are easy and some are impossible. He- requires qualitatively different hardware.) I suspect that if you put in tin instead of lead, you could very easily get a beam at the LHC. I'd guess that there's simply no strong physics case for studying collisions at intermediate masses.