Is a Small Space Hadron Collider More Efficient than a Large One?

[kieyard]

It's to my understanding that the Large Hadron Collider is so 'large' due to the fact E=MC^2 and that when the accelerated particles approach the speed of light their mass increases logarithmic to a near infinite mass, meaning the magnetic force applied to the particle, to stop it from touching the sides of the chamber and slowing down, has to be equal to the particles new weight. Taking this to be correct, if we were to build a Hadron Collider/particle accelerator in outer space where the effects of gravity are almost negligible, would it have to be so large? My reasoning is that it would need less force to keep the particles from touching the sides as there will be less of a gravitational force attracting it to the side. I can see obviously that with my ‘Small Space Hadron Collider’ it would take longer for the particles to reach 99.999% the speed of light like they do in the LHC due to the smaller magnets and less of a Horizontal component accelerating them around but i believe building one in space would also be more efficient as LHC uses a lot of energy to become as close as we can to absolute zero as we can, however this would be a much easier task in space as for one we are in space which is already really really cold (2.6 kelvin or so) and two the SSHC would be smaller and not as much would need cooling. The two major flaws with my idea, which i can see, is first of all getting it into space, which is of course expensive and logistically challenging and secondly powering the thing, solar panels are great but I’m doubting their ability to run the magnets long enough to approach C, even with batteries, capacitors and fuel cells a lot of electrical engineering would be required to supply sufficient power for long enough, in my opinion.So why do it?

My main reason is the production of antimatter, the more we can make and test the closer we get to antimatter rockets and the future of space propulsion, the SSHC could be the very first space fuel station.

it can also answer a lot of fundamental questions scientist have had about not only approaching the speed of light but how these new wondrous particle we discover at the LHC behave in space.I would love to hear you thoughts on this, especially any other ideas on uses, any other major flaws i am not seeing and your general opinion.

 

[ChrisVer]

In the expression E=Mc^2 you wrote, the M refers to the relativistic mass.
You can think that since the particle gets more and more momentum, it's more difficult to keep them on cycling the same radius...If they were free (without magnets to keep them on track), as you would give more energy the particle would cycle in a larger and larger radius circle.
So it's not gravity that changes the track... the thing is that you have a beam that goes around in a circle, and you want to keep its radius constant, although the particles might have more momentum.

 

[Drakkith]

Another problem is that charged particles radiate EM radiation when you accelerate them, which slows them down. A particle accelerator with a large radius requires less centripetal acceleration of the particles than an accelerator with a smaller radius, so you don't lose as much energy, making it easier to accelerate the particles to a high velocity. Electrons are particularly hard hit by this effect due to their small mass.

 

[mfb]

The effect of gravity is always negligible in particle accelerators. I think they are not even considering it at all (and they do consider hundreds of details).

The magnets are not accelerating the particles, they are just keeping them on the curved track.
Electric fields are used to accelerate them, but only at one point (something like 10 meters in the 27000 meter track) - that is sufficient, the time-consuming part is to ramp up the magnets.

Cooling in space is a nightmare as you don't have a good heat sink. You cannot use cooling water or air, everything has to be radiated away with radiators. The temperature of 3 K applies to deep space only, in the solar system the sun keeps everything at a higher temperature. Even reaching ~50 K (necessary for some infrared telescopes) needs a lot of cooling effort. Reaching 2 K would be really hard.

Currently we cannot create, or even store, antimatter in relevant quantities. If you could combine all the antimatter produced (in a controlled way) in the last decades, and let it annihilate at once, it would be sufficient to make coffee once or twice - but not more.

Hadron accelerators are limited by the bending magnets to keep them on the curved track. Electron positron accelerators are limited by synchrotron radiation - if you try to increase the energy too much they lose more than you can feed back to the particles.

Note that the concept of relativistic mass is not used in physics any more, as it leads to misconceptions and makes descriptions harder. This thread describes the reasons in more detail.

 

[ZapperZ]

The OP definitely was not aware of synchrotron radiation loss.

This thread is also the poster child on why more and more of us tend to shy away from using the term "relativistic mass" and why it can be misleading, as proven here. Even Einstein stopped using that term after he realized this.

Zz.

 

[mfb]

The OP definitely was not aware of synchrotron radiation loss.

It is not the energy limit for the LHC. Synchrotron radiation is an issue for the heat limit of the superconducting magnets, but that gets included in the machine design.

 

[ZapperZ]

It is not the energy limit for the LHC. Synchrotron radiation is an issue for the heat limit of the superconducting magnets, but that gets included in the machine design.

Whatever did I write that triggered this response?

I never addressed anything regarding the "energy limit", etc. The OP completely missed the radiation energy loss in the scenario.

Zz.

 

[ChrisVer]

Would any detector be of use in the outer space?
I mean wouldn't cosmic rays be a "bad issue"?

 

[mfb]

Whatever did I write that triggered this response?

I never addressed anything regarding the "energy limit", etc. The OP completely missed the radiation energy loss in the scenario.

Zz.

Sure, but synchrotron radiation energy loss is not the limiting factor for hadron machines, that was my point.

Would any detector be of use in the outer space?
I mean wouldn't cosmic rays be a "bad issue"?

You would probably want some shielding around it, otherwise the muon chambers get spammed by background.

 

[ChrisVer]

You would probably want some shielding around it, otherwise the muon chambers get spammed by background.

There'll probably be no muons... But you would have problems with the higher CR fluxes, unfiltered by the Earth's atmosphere (or ground) and Earth's magnetic field, a larger energy spectrum (making the shielding much more difficult)...

 

[ZapperZ]

Sure, but synchrotron radiation energy loss is not the limiting factor for hadron machines, that was my point.

Well, as an accelerator physicist, and someone involved in studying next generation of particle accelerators, I think I am quite well-acquainted with the ultimate "limiting factor" for hadron machines: THE COST!

I think we are clouding up the rather simple issue that the OP had with all this.

Zz.

 

[ChrisVer]

Are Hadron accelerators more costy than the electron ones?

 

[ZapperZ]

Are Hadron accelerators more costy than the electron ones?

By far! Not only is the source generation more difficult (and costly), but also the RF/magnet/beam control systems are more elaborate. This is before we consider the safety aspect of shielding and radiation control (protons are more damaging than electrons of the same energy).

Zz.

 

[kieyard]

thanks for all the replies guys, i have learned a lot more about hadron and particle accelerators thanks to you, is there any other ways we know about to create antimatter or is it only colliders and finding it in space?

 

[ZapperZ]

We use antimatter regularly. The positrons that are used in medical PET scan didn't come from outer space or particle accelerator.

Zz.

 

[kieyard]

how do we create it for the PET machines? and why can't we use this method to make antimatter as a fuel for space travel?

 

[ZapperZ]

how do we create it for the PET machines? and why can't we use this method to make antimatter as a fuel for space travel?

Just because a decay process can create an antimatter, it does not automatically mean it is suitable for other purposes. For example, we would never use these to create enough positron for an electron-positron collider as proposed for the ILC. They can't be created on demand since they are generated by a radioactive decay. It also produces a small amount compared to the raw parent material, which is why it is suitable to be injected and released inside a human body.

In other words, there is a whole zoo of criteria for any particular purpose. You should never just focus on only one characteristic or property

Zz.

 

[mfb]

We use antimatter regularly. The positrons that are used in medical PET scan didn't come from outer space or particle accelerator.

Well, indirectly. The positrons are produced by radioactive decays of nuclei, those nuclei are produced in particle accelerators before.

Potassium-40 is a notable natural positron emitter.

 

[ZapperZ]

Well, indirectly. The positrons are produced by radioactive decays of nuclei, those nuclei are produced in particle accelerators before.

Potassium-40 is a notable natural positron emitter.

Yes, I'm aware of that. That is why I referred to the positron itself, not the parent compound. One can also make these sources from nuclear reactors, not just accelerator complexes.

Zz.

 

[mfb]

I know you are aware of that, but I don't think this applies to all readers.

How do you make proton-rich nuclei in nuclear reactors?

 

[ZapperZ]

I know you are aware of that, but I don't think this applies to all readers.

How do you make proton-rich nuclei in nuclear reactors?

Transmutation using the neutrons.

Zz.

 

[mfb]

Yeah, I was wondering how that works. Some fast neutrons might induce spallation, but the creation of proton-rich nuclei looks like a very rare process.

 

[ZapperZ]

Yeah, I was wondering how that works. Some fast neutrons might induce spallation, but the creation of proton-rich nuclei looks like a very rare process.

Note that until its shut down, the NRU reactor at Chalk River, Canada was a major supplier of medical isotopes. So the use of accelerators as the major creator of medical isotopes is relatively new.

http://www.aps.org/units/fps/newsletters/200910/ruth.cfm

Zz.

 

[mfb]

That is about Mo-99 and Tc-99m production only, both are neutron-rich and decay via beta-. It is easy to see how those can be produced in an environment with a high neutron flux and fission of neutron-rich nuclei.

 

[BWV]

If you were going to build a particle accelerator in space, wouldn't it be optimal to employ a linear accelerator rather than a ring? Real estate is not an issue and would not have to deal with centripetal issues

 

[kieyard]

If you were going to build a particle accelerator in space, wouldn't it be optimal to employ a linear accelerator rather than a ring? Real estate is not an issue and would not have to deal with centripetal issues

how long would such a thing have to be? as i know with the ring ones it cycles a lot of times before it approaches the speed of light, so unless all of it is an accelerator unit it would have to be pretty long, and even then.

 

[mfb]

If you were going to build a particle accelerator in space, wouldn't it be optimal to employ a linear accelerator rather than a ring? Real estate is not an issue and would not have to deal with centripetal issues

On the other hand, you cannot re-use the acceleration structure (rings can work with a tiny acceleration segment somewhere), and your particles have only one opportunity to collide which makes the process very inefficient. It depends on the science goals which design is better.