Scientists Break Energy Record With "Tabletop" Particle Accelerator

Scientists Break Energy Record With "Tabletop" Particle Accelerator

Lawrence Berkeley National Laboratory's Particle Accelerator, which speeds up electrons in a 9-centimeter plasma tube, just achieved the highest energies ever recorded from a compact accelerator.

When we think about particle accelerators, we usually think of the Large Hadron Collider at CERN, which has a circumference of 17 miles. But particle accelerators can come in various shapes and sizes and can pull off equally impressive feats. Case in point: A team from Lawrence Berkeley National Laboratory uses a laser-plasma accelerator, which they believe can achieve the same results as the LHC while sitting conveniently on a table. And it might be on to something, since their device just broke records for the highest energies seen in a compact accelerator.

Traditional particle accelerators, like the behemoth at CERN, work by modulating electric fields within a metal cavity. The process can only generate about 100 mega-electron volts per meter before the metal wears out, but the laser-plasma accelerator works differently. Using BELLA, the Berkeley Lab Laser Accelerator, injected a pulse of laser light into a 9-centimeter plasma tube, creating waves that trapped free electrons and accelerated them to 4.25 giga-electron volts. "It's similar to the way that a surfer gains speed when skimming down the face of a wave," Berkeley wrote in a recent news release.

While this is already an achievement, director of the Accelerator Technology and Applied Physics Division Dr. Wim Leemans has no plans of stopping here. Leeman's near-term goal is to accelerate these subatomic particles to 10 giga-electron volts, which requires a more precise control of the plasma channel's density. But if the equipment and process can be refined enough to pull it off, you should expect Berkeley to be breaking its own record very soon.

Source: Berkeley Lab

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If I had a suspicious turn of mind, I would suspect that this is a way of generating high energy electrons for a free electron laser for military use.

Also this

image

albino boo:
If I had a suspicious turn of mind, I would suspect that this is a way of generating high energy electrons for a free electron laser for military use.

Also this

Or they're working on the BFG-1000, after all, there had to be models 1 through 8 to get the mark 9.

Every month you hear of some sort of mind blowing tech that is going to change the world. Then we never hear about it. I'm just too jaded now.

Just wait until people start crying "God particle this" and "black hole that".

Omey:
Every month you hear of some sort of mind blowing tech that is going to change the world. Then we never hear about it. I'm just too jaded now.

Because 90% of all research, even very good stuff, is way too boring technical for the average man to be reported in mainstream media.

Omey:
Every month you hear of some sort of mind blowing tech that is going to change the world. Then we never hear about it. I'm just too jaded now.

Just because it fades from the public eye for the moment, doesn't mean it's not still out there. I know that people are working on commericalizing the superhydrophobic stuff that was all the rage a few months back, but it takes time to go from a lab experiment to mass-produced and integrated into everyday life. Heck, for all I know they may already be coating the inside of cement mixers and factory equipment with it; I don't pay attention to that stuff, so I wouldn't know.

OT: The purple image and the word "tabletop" threw me off for a moment. As I was reading, I kept trying to figure out the advantage of subatomic dice.

I just realized I completely misread the title...

I thought it said "table tennis particle accelerator".
Well, that might have been an interesting sport.

Does this mean we'll see an expansion in high-energy particle experiements should this prove we don't have to make a seventeen-mile molecular racetrack for the job?

Thunderous Cacophony:
OT: The purple image and the word "tabletop" threw me off for a moment. As I was reading, I kept trying to figure out the advantage of subatomic dice.

It'll come in handy when you have to roll 3d32000 to save.

The Rogue Wolf:
Does this mean we'll see an expansion in high-energy particle experiements should this prove we don't have to make a seventeen-mile molecular racetrack for the job?

Cern accelerates protons up to 125 GeV, the Berkeley accelerator gets electrons up to 4.25 GeV. The proton is 1836 times more massive than an electron and Ceren accelerates them to almost 30 times greater energy. Furthermore the methodology of using plasma as a medium would hide the data from collisions which is the whole point of Cern.

albino boo:
If I had a suspicious turn of mind, I would suspect that this is a way of generating high energy electrons for a free electron laser for military use.

Nope, plasma wakefield acceleration is a big field being researched all over the world. If it turns out to be capable of producing relatively compact FELs there could turn out to be military applications, but so far at least it's all been entirely scientific in nature.

The Rogue Wolf:
Does this mean we'll see an expansion in high-energy particle experiements should this prove we don't have to make a seventeen-mile molecular racetrack for the job?

That's the hope in theory, but it doesn't look particularly good so far. The important thing with accelerating a beam is that you can pretty much never do it in just one go; the beam passes through a series of accelerating cavities, gaining more energy as it passes through each one. With a circular accelerator, you can have just a few cavities that the beam passes through repeatedly as it goes round and round, with linear accelerators you just have to put lots of them in a line. The big problem PWFA has is that so far it's limited to a single shot - you fire lasers into a plasma, the plasma spits out a bunch of electrons at high energy, the end. You can get much higher energy electrons in a much shorter space than with a traditional RF cavity, but you can't then pass those electrons into another plasma cavity and do it again.

That still has its uses. For example, synchrotron light sources tend to operate at around 2-6 GeV, so PWFA would be ideal as a way to replace the relatively large linacs and booster synchrotron usually used to build up a beam in the main storage rings. But for high energy physics, so far no-one has come up with a way of actually using PWFA to get to high energies. Very high acceleration gradients sound great on paper, but they're not much use if you can't string them together.

There are also some other issues that have yet to be solved, mostly to do with the properties of the beam you get out of it. Things like the size and divergence of the beam and the energy spread of the particles within it are very important parameters that need to be controlled very closely, and beams from PWFA are generally pretty terrible. You can get high energy electrons out of them, but they're not in a state where you can actually do anything useful with them. Pushing higher energies might hit the headlines, but the bulk of research is currently focussed on how to get a better quality beam out, not a higher energy one.

Secondly, the LHC isn't 27km around just because it needs that space for acceleration. The main reason for that is losses due to synchrotron radiation - accelerating (which in this case mainly means turning a corner) a charged particle causes it to emit radiation and therefore lose energy. The loss depends both on the rest mass of the particle (hence the LHC using hadrons to go to higher energies, rather than electrons as in its predecessor LEP) and the radius of the circle. If you want a higher energy circular collider, the only way to avoid crippling energy wastage is to make it a bigger circle.

This is why proposals for even higher energy colliders tend to focus on linear colliders, where you don't have to worry about synchrotron radiation. However, since the particles in a linac only pass each acceleration structure once, you need to string lots of them together as mentioned above. Even assuming we get PWFA working, that's still going to mean accelerators needing to be kilometres long in order to reach higher energies than the LHC (bearing in mind that you need a lot of space for more parts than just the plasma cavities). It will be a hell of a lot easier than it would be using current technology, but it will still mean major projects taking up a lot of space and money.

albino boo:
Cern accelerates protons up to 125 GeV

No. The LHC accelerates hadrons (one of the experiments, ALICE, is specifically designed for lead ion collisions) up to 4TeV.

The proton is 1836 times more massive than an electron and Ceren accelerates them to almost 30 times greater energy.

The rest mass is irrelevant; a particle with an energy of 4TeV is a particle with an energy of 4TeV. A proton with that energy will be travelling slower than an electron with the same energy, but exactly the same acceleration is involved in getting them there.

Furthermore the methodology of using plasma as a medium would hide the data from collisions which is the whole point of Cern.

No it wouldn't. Firstly, just because a plasma is involved in one part of the accelerator doesn't mean you have to fill the whole thing with it. Secondly, even if you did fill the whole thing with plasma, it would have no effect on the detectors at all. The whole point of particle detectors at a collider is that they see high energy particles that have already passed straight through the beam pipe. Obviously a low energy plasma contained inside the beam pipe does not fit that description.

albino boo:
If I had a suspicious turn of mind, I would suspect that this is a way of generating high energy electrons for a free electron laser for military use.

How else are they supposed to get funding? Not like there's a lot of money in theoretical physics unless you can demonstrate practical applications. This could be used for more than just weapons though. Plenty of industrial applications too (like super-precise fabrication).

Avaholic03:

albino boo:
If I had a suspicious turn of mind, I would suspect that this is a way of generating high energy electrons for a free electron laser for military use.

How else are they supposed to get funding? Not like there's a lot of money in theoretical physics unless you can demonstrate practical applications. This could be used for more than just weapons though. Plenty of industrial applications too (like super-precise fabrication).

Lawrence Berkeley National Laboratory is funded by the department of energy and has been working on military projects since the Manhattan project in the 40s. One of their major developments was the radar proximity fuse. Its an arm of the US government that has been heavily involved in military research for 70 years

Kahani:

That's the hope in theory, but it doesn't look particularly good so far. The important thing with accelerating a beam is that you can pretty much never do it in just one go; the beam passes through a series of accelerating cavities, gaining more energy as it passes through each one. With a circular accelerator, you can have just a few cavities that the beam passes through repeatedly as it goes round and round, with linear accelerators you just have to put lots of them in a line. The big problem PWFA has is that so far it's limited to a single shot - you fire lasers into a plasma, the plasma spits out a bunch of electrons at high energy, the end. You can get much higher energy electrons in a much shorter space than with a traditional RF cavity, but you can't then pass those electrons into another plasma cavity and do it again.

That still has its uses. For example, synchrotron light sources tend to operate at around 2-6 GeV, so PWFA would be ideal as a way to replace the relatively large linacs and booster synchrotron usually used to build up a beam in the main storage rings. But for high energy physics, so far no-one has come up with a way of actually using PWFA to get to high energies. Very high acceleration gradients sound great on paper, but they're not much use if you can't string them together.

There are also some other issues that have yet to be solved, mostly to do with the properties of the beam you get out of it. Things like the size and divergence of the beam and the energy spread of the particles within it are very important parameters that need to be controlled very closely, and beams from PWFA are generally pretty terrible. You can get high energy electrons out of them, but they're not in a state where you can actually do anything useful with them. Pushing higher energies might hit the headlines, but the bulk of research is currently focussed on how to get a better quality beam out, not a higher energy one.

Would you consider this potentially a massive waste of time or potentially great depending on what applications can be found for the sort of beam and it's properties that actually results from the process?

Interesting, though I'm not 100% sure what it does myself. Still I love when science keeps doing new stuff, just as long as they don't end up making something that causes more issues than it solves. Omelettes and eggs and all that yes, but still science tempered with pragmatism is a good thing IMO.
I'm quite happy if this leads to better energy sources and such.

Lightknight:
Would you consider this potentially a massive waste of time or potentially great depending on what applications can be found for the sort of beam and it's properties that actually results from the process?

Very much the latter. Even if it doesn't work out and we never find anything particularly useful to do with it, research like this is never a waste of time. The thing about advancing science is that we never know what we're going to find out; if we did, we wouldn't need to be researching it in the first place. PWFA might be a useless dead-end, or it might turn out to be a huge revolution that leads to a world full of flying cars and jetpacks. Something in between may be a bit more likely. Unless we spend a bit of time and money figuring out, we'll never know which.

I am going to admit that I did not understand almost anything about this article. Plasma Giga-Electrons? It sounds awesome, and I feel very sciency reading this, but this is well beyond my comprehension.

I suck apparently.

Now I am going to go and cry.

Kahani:

Lightknight:
Would you consider this potentially a massive waste of time or potentially great depending on what applications can be found for the sort of beam and it's properties that actually results from the process?

Very much the latter. Even if it doesn't work out and we never find anything particularly useful to do with it, research like this is never a waste of time. The thing about advancing science is that we never know what we're going to find out; if we did, we wouldn't need to be researching it in the first place. PWFA might be a useless dead-end, or it might turn out to be a huge revolution that leads to a world full of flying cars and jetpacks. Something in between may be a bit more likely. Unless we spend a bit of time and money figuring out, we'll never know which.

Thanks for responding.

Who knows, we could even find no applications now but find significant applications decades from now. We've seen several innovations like that crop up once the means to harness the findings becomes available.

 

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