Accelerate an Uncharged Particle?

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Discussion Overview

The discussion centers around the conceptual possibility of building a particle accelerator that can accelerate uncharged particles with non-zero rest mass, such as neutrons. Participants explore various interactions and mechanisms that could potentially facilitate this process, including the roles of different fundamental forces.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants note that conventional particle accelerators utilize electromagnetic (EM) forces to accelerate charged particles, questioning how uncharged particles could be accelerated directly.
  • High energy neutrons can be produced by accelerating deuterons and stripping off protons, but this still relies on initial acceleration of charged particles.
  • One participant suggests using gravity as a potential means of acceleration, although they note that gravity is not typically considered a force in the same way as EM.
  • Another participant proposes the idea of using a charged black hole to accelerate neutrons, although this remains speculative.
  • Discussion includes the four fundamental interactions (weak, strong, EM, and gravity) and their applicability to accelerating uncharged particles, with emphasis on the limitations of weak and strong forces due to their short-range nature.
  • One participant raises a question about the nature of interactions during neutron-proton scattering, seeking clarification on whether this involves one of the four fundamental forces or is merely a quantum mechanical effect.
  • Another participant responds by affirming that scattering does involve one of the four forces, emphasizing that without interactions, the wave functions of the particles would not interact.

Areas of Agreement / Disagreement

Participants express a range of views on the feasibility of directly accelerating uncharged particles, with no consensus reached on a specific method or model. The discussion remains unresolved regarding the best approach to achieve this goal.

Contextual Notes

Participants highlight limitations in current understanding, particularly regarding the applicability of different forces for accelerating uncharged particles and the nature of particle interactions in quantum mechanics.

LarryS
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Particle accelerators use EM to guide and accelerate charged particles to close to the velocity of light. Is it conceptually possible to build a particle accelerator to accelerate uncharged particles that have a non-zero rest mass? Thanks in advance.
 
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referframe said:
Particle accelerators use EM to guide and accelerate charged particles to close to the velocity of light. Is it conceptually possible to build a particle accelerator to accelerate uncharged particles that have a non-zero rest mass? Thanks in advance.

What concept would you use? Neutron sources facilities all over the world would like to know.

Zz.
 
High energy neutrons can be produced by accelerating deuterons, and "stripping" off the protons. Other high energy neutral particles can come from "charge exchange" interactions or the decay of much heavier particles.
 
clem said:
High energy neutrons can be produced by accelerating deuterons, and "stripping" off the protons. Other high energy neutral particles can come from "charge exchange" interactions or the decay of much heavier particles.

But these, and the ones used at spallation neutron sources, still use conventional particle accelerators to accelerate charged entities first. The OP is asking for a direct acceleration of neutral particles.

Zz.
 
ZapperZ said:
What concept would you use? Neutron sources facilities all over the world would like to know.

Zz.

Oooo, a tame lump of neutron star?
 
bomanfishwow said:
Oooo, a tame lump of neutron star?

Then why stop there? Why not just get one of those big bad black hole? I hear CERN might have quite a few to sell once they get the LHC back on track.

Zz.
 
ZapperZ said:
But these, and the ones used at spallation neutron sources, still use conventional particle accelerators to accelerate charged entities first. The OP is asking for a direct acceleration of neutral particles.

Zz.

Yes. I cannot think of an example (at least in the micro world) of F = ma where the "F" is not EM and the "m" is uncharged. Gravity, being basically a field of acceleration, is no longer considered an "F". Also, uncharged particles created from heavier particles or from collisions are not, in my opinion, an example of F = ma.
 
referframe said:
Gravity, being basically a field of acceleration, is no longer considered an "F".
I was actually thinking, to accelerate your neutrons, use a charged black hole !
 
To accelerate something, you interact with it.

We know about four interactions, weak, strong, EM, and gravity.

EM is convenient, because it's a long-distance force (carrier of the interaction is massless).

Gravity also works, for the same reason, but it's weaker. You could put a neutron at the top of a very tall tower and it will accelerate towards the ground.

Weak and strong forces are short-distance. Weak is short-distance because it's carriers are very heavy, and strong is short-distance because there are no free gluons and you need heavy particles (e.g. virtual pions) to mediate the interaction. You need a long-distance force accelerate a particle in the vacuum far from any other objects.

That does not mean that you can't use weak and strong interactions at all. You could create a cloud of neutrons and fire a beam of protons at it. Some protons will scatter on neutrons and pass momentum on to them.
 
  • #10
hamster143 said:
To accelerate something, you interact with it.

We know about four interactions, weak, strong, EM, and gravity.

EM is convenient, because it's a long-distance force (carrier of the interaction is massless).

Gravity also works, for the same reason, but it's weaker. You could put a neutron at the top of a very tall tower and it will accelerate towards the ground.

Weak and strong forces are short-distance. Weak is short-distance because it's carriers are very heavy, and strong is short-distance because there are no free gluons and you need heavy particles (e.g. virtual pions) to mediate the interaction. You need a long-distance force accelerate a particle in the vacuum far from any other objects.

That does not mean that you can't use weak and strong interactions at all. You could create a cloud of neutrons and fire a beam of protons at it. Some protons will scatter on neutrons and pass momentum on to them.

Forgive my ignorance: When the protons "scatter" on the neutrons does that involve one of the 4 forces ("interactions") of nature or is that just the wave function of the proton interacting with the wave function of the neutron in the QM equivalent of a classical 2-particle collision?
 
  • #11
no, the interaction probability amplitude is:

i) Operate on initial state with Interaction Hamiltonian (e.g the "force" under consideration, weak, Em or Strong)

ii) take result times final state

iii) integrate over space, multiply with phase space

So that is the basic procedure. You have wavefuntions and an interaction hamiltonian.
 
  • #12
referframe said:
Forgive my ignorance: When the protons "scatter" on the neutrons does that involve one of the 4 forces ("interactions") of nature or is that just the wave function of the proton interacting with the wave function of the neutron in the QM equivalent of a classical 2-particle collision?

It involves one of the 4 forces. In the absence of interactions, the wave function of the proton and the wave function of the neutron would just pass through each other.
 

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