4 ms·

These things come up and are always amusing (my favorite was the "video" of the LHC starting up). I wonder though, assuming no supernatural world-ending phenome

by daveguy 11y ago

These things come up and are always amusing (my favorite was the "video" of the LHC starting up). I wonder though, assuming no supernatural world-ending phenomenon, what is the worst that could happen given the energy involved? This is high-energy particle physics, using magnets to guide collisions? How high is the energy? Can we put a value on the intensity of a complete and 100% efficient conversion of the particle collider energy to kinetic energy? Would it be like a 1 megaton nuclear bomb? Not even that? 1000x that? Do all concerns involve some unknown-maybe phenomenon like a runaway black hole? If we assume conservation of energy, what is the worst? Anyone know?

the8472 11y ago
> what is the worst that could happen given the energy involved? The beam alone carries enough energy to melt a tank, that's why they need those massive, water-cooled beam dumps. All the magnets combined store 11GJ of energy, which is 2.6 tons of TNT energy equivalent. Considering that they're distributed along the accelerator I guess it would result in a spectacular destruction of equipment, but no fireballs on the surface or anything like that.
- beamatronic 11y ago
  The whole tank? Or did you mean it can make a teeny tiny hole all the way straight through it?
  - the8472 11y ago
    Now that I looked it up, the analogy used was "could melt half a ton of copper". So it's less than your average car. Still a lot of energy to get rid off at short notice, in case of emergency shutdowns. If I recall correctly they modulate the beam with steering magnets so it sweeps through an area and water-cool the target material. And its absorption can't be too high so the energy gets deposited over some depth. Or from wikipedia: > Each of the two beam dumps, in case, for instance, of a dipole magnet quench, must be able to dissipate 362 MJ of beam energy in the 90 μs circulation time, which equates to a power of 4 TW.
jloughry 11y ago
Yes. The LHC has a beam dump off to the side, tonnes of concrete and steel buried underground, specifically for the purpose of dissipating the entire beam energy if needed. It's about the same as the kinetic energy of an aircraft carrier stopping from speed: https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/components/beam-dump.htm https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreac... http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/beam.htm http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach...

by daveguy 11y ago

the8472 11y ago

> what is the worst that could happen given the energy involved? The beam alone carries enough energy to melt a tank, that's why they need those massive, water-cooled beam dumps. All the magnets combined store 11GJ of energy, which is 2.6 tons of TNT energy equivalent. Considering that they're distributed along the accelerator I guess it would result in a spectacular destruction of equipment, but no fireballs on the surface or anything like that.

beamatronic 11y ago
The whole tank? Or did you mean it can make a teeny tiny hole all the way straight through it?
- the8472 11y ago
  Now that I looked it up, the analogy used was "could melt half a ton of copper". So it's less than your average car. Still a lot of energy to get rid off at short notice, in case of emergency shutdowns. If I recall correctly they modulate the beam with steering magnets so it sweeps through an area and water-cool the target material. And its absorption can't be too high so the energy gets deposited over some depth. Or from wikipedia: > Each of the two beam dumps, in case, for instance, of a dipole magnet quench, must be able to dissipate 362 MJ of beam energy in the 90 μs circulation time, which equates to a power of 4 TW.

jloughry 11y ago

Yes. The LHC has a beam dump off to the side, tonnes of concrete and steel buried underground, specifically for the purpose of dissipating the entire beam energy if needed. It's about the same as the kinetic energy of an aircraft carrier stopping from speed: https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/components/beam-dump.htm https://lhc-machine-outreach.web.cern.ch/lhc-machine-outreac... http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/beam.htm http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach...