Energy loss in the beam of LHC

Click For Summary
SUMMARY

The discussion centers on energy loss in the Large Hadron Collider (LHC) beam and its interaction with quantum mechanical concepts, particularly the vacuum state. Participants clarify that while the uncertainty principle implies that no space is completely empty, virtual particles do not interact with particle beams in a meaningful way. The conversation also touches on the Casimir effect and the implications of a high-speed proton beam (0.99c) passing between Casimir plates, emphasizing that classical electrodynamics and relativistic mechanics govern these interactions rather than quantum "voodoo." The importance of clear communication and understanding misconceptions in physics is also highlighted.

PREREQUISITES
  • Understanding of quantum mechanics, specifically the uncertainty principle
  • Familiarity with particle physics and the behavior of proton beams
  • Knowledge of the Casimir effect and its implications in quantum field theory
  • Basic principles of classical electrodynamics and relativistic mechanics
NEXT STEPS
  • Research the implications of the uncertainty principle in quantum mechanics
  • Study the Casimir effect and its relevance in modern physics
  • Explore the dynamics of high-speed particle beams in accelerators like the LHC
  • Learn about the interactions between electromagnetic fields and charged particle beams
USEFUL FOR

Physics students, particle physicists, and researchers interested in the interactions of particle beams with quantum fields and vacuum states.

phoenix95
Gold Member
Messages
81
Reaction score
23
TL;DR
Could the beam lose energy purely because of the quantum mechanical nature of vacuum?
Generally, one would expect the beam to lose its content (energy or particles) if it hits anything before its reaching its target. The whole idea of maintaining (conventional) vacuum using pumps or other means is to minimize that loss. But is it possible that there could be a beam loss purely because of a quantum mechanical vacuum? That is because the uncertainty principle guarantees that no space is completely empty and so there would be inevitable and unavoidable beam loss?
 
Physics news on Phys.org
The beam has zero kinetic energy in the reference frame of the beam. Where would the energy come from to change that, and in which direction would the particles accelerate?
phoenix95 said:
That is because the uncertainty principle guarantees that no space is completely empty
It doesn't.
 
phoenix95 said:
That is because the uncertainty principle guarantees that no space is completely empty
Huh? What? I don't understand what this means.
 
  • Like
Likes   Reactions: phoenix95
phoenix95 said:
That is because the uncertainty principle guarantees that no space is completely empty
Isn't it true that there would always be quantum fluctuations? Virtual particles-antiparticle pairs being created and annihilated, or was I wrong when I assumed (at least implicitly) that "the beam can interact with the quantum fluctuations/virtual particles"?

I think my main confusion here is whether or not the beam (or any matter particle) can interact with virtual particles.
 
  • Skeptical
Likes   Reactions: weirdoguy
phoenix95 said:
Virtual particles-antiparticle pairs being created and annihilated
There is no such process, no matter how often popular science descriptions repeat that myth.

Virtual particles are tools in some calculations. They are as real as an integral sign. Particle beams don't interact with integral signs either.
 
  • Like
  • Informative
  • Love
Likes   Reactions: Imager, Keith_McClary, vanhees71 and 5 others
I think @phoenix95 was thinking the vacuum energy aka zero point energy that is theorized and predicted to exist throughout space even under complete vacuum. The particles he was talking about are probably the particles said to spontaneously be created due to the underlying vacuum field.
So if I can and if that makes any sense I could rephrase his original question into " how would the passing of a 0.99c proton beam through the Casimir plates affect the outcome of the Casimir plate experiment if one was able to pass such a proton beam through the narrow opening between such plates"
 
  • Like
Likes   Reactions: phoenix95
It would have nothing to do with the Casimir effect, but the proton bunches come with a strong electromagnetic field, which would interact with following bunches - most likely leading to an emergency beam dump. It would also lead to forces on the plates far stronger than the Casimir effect.
 
  • Like
Likes   Reactions: phoenix95
It is a bad idea to speculate about what the OP "really means", which I will now demonstrate. It's better to ask and let them answer.

"the passing of a 0.99c proton beam through the Casimir plates"

Obviously when the beam hits through the plates there will be a spray of secondary particles when it hits them. Thick enough and the beam will stop in tehm.

"No, no! Not through that way! Through the other way! Between them!"

Casimir plates are conductors. The beam is a current. The beam will generate an image current on the plates. The magnetic forces from the image current will affect the beam - coupling the head of the beam to the tail of the beam. This causes an instability.

"No. no! This is ordinary! I want Casimir magic! Vacuum voodoo! Beam bippity boppity boo!"

<sigh>
 
  • Like
  • Love
Likes   Reactions: phoenix95, nsaspook and weirdoguy
I think quantum theory is exciting enough without all the voodoo many popular-science books claim just to be sold. Already the Casimir effect has nothing to do with a "pure vacuum" but it's about (quantum) fluctuations of the charges making up the plates. Having a proton beam as delivered from the LHC between the plates you are very far from having vacuum at all and fortunately the protons in the accelerator can be described by classical electrodynamics and (relativistic) mechanics. No "quantum voodoo" needed ;-).
 
  • Like
Likes   Reactions: Delta2, phoenix95 and Mondayman
  • #10
My apologies for replying late. I forgot about the thread after that answer from @mfb which I thought was good enough. Let me just make some remarks.

Sometimes when I have a question, it is not obligated to receive an answer by any means; it could very well be possible that the question was framed on the basis of a misconception, and asking that question nonetheless would help clear out that misconception.:smile: This is exactly what happened in #4 and#5. In all honesty, you did not have to reply to a senseless question (one could say that is the purpose of the platform, but given that I was talking about LHC beams and the quantum vacuum should hint at least some background in physics; which means I should have paid attention to my homework, which would have stopped that misconception in its tracks) but you did, and I thank you for that.

What @artis mentioned in #6 was exactly what I meant when I said quantum vacuum in #1. But as I said, the answer by @mfb in #5 cleared it out.

Now let me address this:

If
Vanadium 50 said:
It is a bad idea to speculate about what the OP "really means", which I will now demonstrate.
then why are speculating that OP and/or other poster meant
Vanadium 50 said:
"No. no! This is ordinary! I want Casimir magic! Vacuum voodoo! Beam bippity boppity boo!"

<sigh>
? To put it in a sentence: Why would you assume that the person is only asking that question for the sake/interest of "quantum voodoo"?:smile:
vanhees71 said:
I think quantum theory is exciting enough without all the voodoo many popular-science books claim just to be sold.
Yes, of course. Maybe that is probably why the OP is interested in LHC beams and not 'goop lab von Netflix'.:wink:

I'm sorry if this post seems a bit aggressive. I understand the fault was in my own misconception as well as the wording of the thread; I didn't mean to offend any of the mentors/advisors above. It is contradictory when the academia around me boasts "Ask questions. There are no stupid questions only stupid answers (and other inspirational quotes that are too much to fit in this quotation)". And when I do then I hear "Oh that is a stupid question. Well, you should have done your homework. Where do get these? From Quantum voodoo?". In the post I wrote above, I had two concepts that I had known: vacuum/virtual particles and LHC beams. I was merely asking how the two reconciled with each other. And for that same matter
Vanadium 50 said:
"the passing of a 0.99c proton beam through the Casimir plates"
is just another student trying to reconcile their own understandings of two different things. I might have very well asked, "What would be the energy of the LHC beam that is required such that firing it through a dripping faucet would stop the dripping, after considering gravity and friction". Sure, it is a dumb question. But not necessarily as bad as the need to <sigh>.

I know all of you mentors. Either directly or indirectly, you have helped me on this platform many times before. Knowing your expertise, it would be impudent of me to say that your approach is wrong. I just hope that the atmosphere here remains the same for other students (and for me; to be honest it's just for me, I added the phrase 'other students' to seem polite and empathizing:oldbiggrin:) to come. Please don't brush off any questions as 'unworthy'.:smile:
 
Last edited:
  • Like
Likes   Reactions: Delta2

Similar threads

  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
8
Views
3K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K
  • · Replies 4 ·
Replies
4
Views
4K
  • · Replies 1 ·
Replies
1
Views
1K