LHC Beam Energies: Highest Possible Energy

  • Context: Graduate 
  • Thread starter Thread starter Gear300
  • Start date Start date
  • Tags Tags
    Beam Energies Lhc
Click For Summary

Discussion Overview

The discussion revolves around the highest possible energy per beam that the Large Hadron Collider (LHC) can handle, including considerations of design specifications, operational limits, and energy management. Participants explore theoretical limits, practical constraints, and the implications of energy levels on detector performance and safety.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants suggest that the LHC was designed to operate at 7 TeV per beam, leading to a total collision energy of 14 TeV.
  • Others express uncertainty about the maximum energy the magnets can handle, with some indicating that 5 TeV per beam might be a more realistic target due to safety concerns.
  • One participant mentions that the LHC will initially run at 3.5 TeV per beam for about two years before attempting to reach full design energy.
  • Another participant calculates that the total energy in the LHC could be around 200-300 kJ, comparing it to the energy content of a potato.
  • It is noted that at full energy, the LHC contains approximately 350 MJ per beam, with discussions on how this energy is managed and dissipated safely.
  • Participants discuss the cooling systems and energy absorption mechanisms, including the role of the beam dumper in managing excess energy.
  • Concerns are raised about the heat generated in the detectors during collisions, with some arguing that the energy from individual collisions is negligible compared to the heat produced by electronics.

Areas of Agreement / Disagreement

Participants express differing views on the maximum energy the LHC can achieve, with some proposing 7 TeV per beam while others suggest lower limits due to operational constraints. The discussion remains unresolved regarding the exact limits and implications of energy management.

Contextual Notes

Participants highlight uncertainties regarding the handling capacity of magnets and the actual energy levels during operation, as well as the complexities involved in energy dissipation and cooling systems.

Who May Find This Useful

Readers interested in high-energy physics, particle accelerator technology, and the operational challenges of large-scale scientific experiments may find this discussion relevant.

Gear300
Messages
1,209
Reaction score
9
What is the highest possible energy per beam that the LHC can handle?
 
Physics news on Phys.org
Gear300 said:
What is the highest possible energy per beam that the LHC can handle?

7TeV per beam 14TeV total I believe. So it will be half max on 30th...if all goes well(touch wood).
 
It was initially planned for 7 TeV per beam ... but now it turns out that no one really knows how much magnets can handle. Fingers crossed, we might get to 5 per beam if we're lucky.
 
Last edited by a moderator:
I guess that you think of energy per proton and not per beam.
 
naima said:
I guess that you think of energy per proton and not per beam.

Yes, the numbers quoted are per proton. It was designed to run at 7 TeV per proton (or a center-of-mass collision energy of 14 TeV). In light of the problems they had with the magnets, they decided that to avoid risk they will run for ~2 years at 3.5 TeV beam energy, and then shut down to replace all the interconnects before resuming and ramping up to full design energy.

So it's a good bet that they'll eventually have 14 TeV collsions, it will just take a while.

As for the total energy in the the beam at one time, I'll let someone else answer that since I don't know offhand, but it's considerable. I believe they'll eventually have a pretty high luminosity.
 
The total energy in the LHC a week from now will be on the order of 200-300 kJ - about the same as the food energy in a potato. This is calculated assuming 4x4 bunches, 3.5 TeV per proton, and 5-6 x 1010 protons per bunch.
 
At full energy and full power the LHC contains about 350MJ /beam

They helpfully convert that into units of aircraft carriers steaming at X knots - for both British and American aircraft carriers.
(In case you were wondering it's equal to HMS Illustrious at 12Knots or USS Nimitz at 5.5knots)
http://lhc-machine-outreach.web.cern.ch/lhc-machine-outreach/beam.htm

Actually turning the thing off and getting rid of this energy without making a mess is a big part of the design
 
Last edited:
mgb_phys said:
Actually turning the thing off and getting rid of this energy without making a mess is a bit part of the design

That is a lot of energy, and the LHC detectors might produce 10^34 collisions per second and per cm^2. A layman would assume that there is a lot of heat produced going one, but these collisions happen in a vacuum, where heat transfer is only possible by conduction and/or radiation. Where does the energy actually goes? And if there is a cooling installation doesn't this affect the results?
 
  • #10
The LHC beam dumper is located in point 6 of the main ring. Basically it will take a magnet and deflect each beam into a very large concrete and iron lined, water cooled carbon chamber which absorbs the beam.
 
  • #11
MotoH said:
The LHC beam dumper is located in point 6 of the main ring. Basically it will take a magnet and deflect each beam into a very large concrete and iron lined, water cooled carbon chamber which absorbs the beam.
That's cool, and what happens to the temperature in rooms where the collisions are do these detectors get red hot?
 
  • #12
Chelle12 said:
That's cool, and what happens to the temperature in rooms where the collisions are do these detectors get red hot?

Note that the 350 MJ refers to dumping the entire beam. The collisions that are being studied only happen a few at a time, so the resulting ~10^-6 J of total energy added to the detectors as a whole from each event is negligible (as far as I know anyway).
 
  • #13
The power in collisions entering the detector at design is measured in watts. In the early phase, mW or even uW would be more appropriate. "Red hot" is not in the realm of possibility. By far the more important source of heat is all the electronics.
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 23 ·
Replies
23
Views
3K
  • · Replies 13 ·
Replies
13
Views
4K
  • · Replies 57 ·
2
Replies
57
Views
16K
  • · Replies 1 ·
Replies
1
Views
2K