In fact that's the beautiful, and arguably the most perplexing, thing abbout graphene. Charge carriers travel thousands of interatomic distances without scattering, even when under 'dirty' conditions. Adsorbates, proximal substrates, lattice vibrations, none of these seems to phase the carriers in their passage from one place to another. This is truly astounding, and we really don't yet know why. But it does suggest that this is one less big thing to worry about when it comes to making devices.
Moreover, graphene is structurally robust, even down to an atom thick and sub-10-nm wide. It doesn't fall apart, it doesn't aggregate, it doesn't oxidize --- it's just happy to be what it is. This is not as astounding as the ballistic nature of it's carriers --- the carbon-carbon bond in graphene/graphite is one of the strongest known, stronger even than the carbon-carbon bond of diamond! Nonetheless, even the most naively optimistic researchers find this pretty amazing.
Of course, there are *lots* of other big things to worry about, it's just that material and electronic stability aren't among them.
As per making a ballistic field-effect transistor (a la a carbon nanotube FET), this has already been done, and the characteristics are rubbish! And there's no way around this. Conventional device structures in graphene leak like sieves, which seems to be fundamental rather than a consequence of fabrication issues. Which is why the SET result is so encouraging. The characteristics are still not fabulous, or at least not yet, but it's likely that this could be the only way to make a transistor with useful ON-OFF behaviour.
Oh, and CNTs are never going to be a goer for consumer electronics, imho. Their properties are just too dependent on their chirality (which determines even whether they are semiconducting or metallic), and there is still no good way of addressing this. Graphene doesn't suffer from this problem, the properties of one sheet are the same as those of any other sheet. Rotational alignment and edge structure could causes problems at the dimensions people are talking about for future single electron devices. But at least you don't have the problem of not knowing if you've even got a metal or a semiconductor, as you do with nanotubes.
But then of course, there are all those unseen issues to come. But that's the wonderful thing about emerging fields of research, you get to wax lyrical about all the great possibilities that could be without all those bothersome reality-induced pitfalls that always arise. We're still in the honeymoon period of graphene research. How long the actual marriage will last is anyone's guess.
I'd me more concerned about what the power source that drove the laser that drove a CERN-sized accelerating plasma would do to the life forms around it if you turned it on.
To be honest, the approach is not the sort of thing that is scalable to that sort of size, so it's a moot point... or at least it is on this planet. But I wouldn't be surprised if similar sorts of processes were sustainable in the vicinity of various astophysical objects like pulsars and the like. But that's beyond my knowledge-base.
MW fibre lasers pack more of a punch than the TW/PW pulsed lasers used for accelerators. DARPA are funding the development of a fibre laser system that could be mounted in a jet fighter... but it seems to me you'd be better off mounting it in a satellite. At a guess I'd reckon the attentuation from both is similar, but it seems easier to direct a beam onto an enemy facility (such as an oil depot) from geostationary orbit (even if you have to wait for a fine day) than from a moving jet fighter.
But back towards the topic, the *really* cool (and certainly more evil sounding) physics won't begin to emerge until the development of exawatt lasers. At this point it may be possible to literally BOIL the vacuum with light. I don't know if this would enable you to break a hole into a hell dimension, but it certainly sounds plausible, doesn't it? Someone should alert Michael Crichton!
Lots of potential uses, but it's fair to say that laser-driven particle accelerators (also known as laser wakefield accelerators [LWFAs] or, less accurately, 'desktop accelerators') still have a way to go before they become widespread.
The one that is most often mentioned is for cancer therapy. The way a beam of particles interacts with living tissue (or indeed all matter) is quite different to the way a beam of ionizing electromagnetic radiation that is conventionally used in radiotherapy does. When a high energy electron, proton or ion enters the body, it does relatively little damage along its path as it slows, until it reaches the end of its range, where it does a great deal of damage. In contrast, a single beam of ionizing photons does pretty much the same amount of damage right along its path (unless it is strongly absorbed, in which case most of the damage will be at the surface). Moreover, the range of a given particle of a given energy in a given material will be very well defined. Consequently, you should be able to better target a tumour present at a fixed depth in a patient's body, and with less collateral tissue damage, with a beam of high-energy particles than a beam of high-energy photons.
It is potentially possible to use a conventional particle accelerator to generate such a beam. But these are bigger, more expensive, and produce beams of less brightness than the laser-driven accelerators that have been recently developed. It is certainly fair to say that these systems are not yet desktop sized, and the size and expense of the lasers that drive them must of course be brought into consideration in assessing their potential. However, laser technology is progressing at a far greater rate than is conventional accelerator technology, and it is not inconceivable that the sorts of laser necessary to generate the particle beams necessary for cancer therapy could soon be small enough, and cost-effective enough to be widely available (how widely, of course, remains to be seen).
Also, it's much easier to manipulate the laser beam towards the patient (where it can be used to generate a particle beam within a very small space... viz. the 3.3cm GeV accelerator result that has made the headlines recently) than to do the same with a conventionally produced particle beam.
How soon will this happen? It's difficult to say. My guess is of the order of a decade or more (but this is only a guess). A substantial increase in the average energy and decrease in the energy spread of the beams produced will be necessary, but progress in both is still very encouraging. And I wouldn't be surprised if clinical trials of the use of electron beams produced in this way for treating shallow tumours, began in the next few years.
But cancer therapy is not the only possibility, of course. As has already been mentioned, the beams produced by these devices could readily be used for making medical isotopes. And they can also be used for generating short bursts of X-rays, which have all manner of uses in biological and medical research (viz. the current, and increasing, buzz about Free Electron Lasers, used also for pulsed X-ray generation, but developed out of conventional accelerator technology... another unanticipated app from fundamental physics research).
And last, but certainly not least, it promises an entirely new frontier for learning stuff about the Universe. And surely that in itself is enough, isn't it?
Slashdot Mirror
In fact that's the beautiful, and arguably the most perplexing, thing abbout graphene. Charge carriers travel thousands of interatomic distances without scattering, even when under 'dirty' conditions. Adsorbates, proximal substrates, lattice vibrations, none of these seems to phase the carriers in their passage from one place to another. This is truly astounding, and we really don't yet know why. But it does suggest that this is one less big thing to worry about when it comes to making devices.
Moreover, graphene is structurally robust, even down to an atom thick and sub-10-nm wide. It doesn't fall apart, it doesn't aggregate, it doesn't oxidize --- it's just happy to be what it is. This is not as astounding as the ballistic nature of it's carriers --- the carbon-carbon bond in graphene/graphite is one of the strongest known, stronger even than the carbon-carbon bond of diamond! Nonetheless, even the most naively optimistic researchers find this pretty amazing.
Of course, there are *lots* of other big things to worry about, it's just that material and electronic stability aren't among them.
As per making a ballistic field-effect transistor (a la a carbon nanotube FET), this has already been done, and the characteristics are rubbish! And there's no way around this. Conventional device structures in graphene leak like sieves, which seems to be fundamental rather than a consequence of fabrication issues. Which is why the SET result is so encouraging. The characteristics are still not fabulous, or at least not yet, but it's likely that this could be the only way to make a transistor with useful ON-OFF behaviour.
Oh, and CNTs are never going to be a goer for consumer electronics, imho. Their properties are just too dependent on their chirality (which determines even whether they are semiconducting or metallic), and there is still no good way of addressing this. Graphene doesn't suffer from this problem, the properties of one sheet are the same as those of any other sheet. Rotational alignment and edge structure could causes problems at the dimensions people are talking about for future single electron devices. But at least you don't have the problem of not knowing if you've even got a metal or a semiconductor, as you do with nanotubes.
But then of course, there are all those unseen issues to come. But that's the wonderful thing about emerging fields of research, you get to wax lyrical about all the great possibilities that could be without all those bothersome reality-induced pitfalls that always arise. We're still in the honeymoon period of graphene research. How long the actual marriage will last is anyone's guess.
And some day, Dorothy, you may. The same subset of researchers are working on that too! :-)
To be honest, the approach is not the sort of thing that is scalable to that sort of size, so it's a moot point... or at least it is on this planet. But I wouldn't be surprised if similar sorts of processes were sustainable in the vicinity of various astophysical objects like pulsars and the like. But that's beyond my knowledge-base.
And the original research paper can be found at http://dx.doi.org/10.1038/nphys442 (subscription required)
But back towards the topic, the *really* cool (and certainly more evil sounding) physics won't begin to emerge until the development of exawatt lasers. At this point it may be possible to literally BOIL the vacuum with light. I don't know if this would enable you to break a hole into a hell dimension, but it certainly sounds plausible, doesn't it? Someone should alert Michael Crichton!
The one that is most often mentioned is for cancer therapy. The way a beam of particles interacts with living tissue (or indeed all matter) is quite different to the way a beam of ionizing electromagnetic radiation that is conventionally used in radiotherapy does. When a high energy electron, proton or ion enters the body, it does relatively little damage along its path as it slows, until it reaches the end of its range, where it does a great deal of damage. In contrast, a single beam of ionizing photons does pretty much the same amount of damage right along its path (unless it is strongly absorbed, in which case most of the damage will be at the surface). Moreover, the range of a given particle of a given energy in a given material will be very well defined. Consequently, you should be able to better target a tumour present at a fixed depth in a patient's body, and with less collateral tissue damage, with a beam of high-energy particles than a beam of high-energy photons.
It is potentially possible to use a conventional particle accelerator to generate such a beam. But these are bigger, more expensive, and produce beams of less brightness than the laser-driven accelerators that have been recently developed. It is certainly fair to say that these systems are not yet desktop sized, and the size and expense of the lasers that drive them must of course be brought into consideration in assessing their potential. However, laser technology is progressing at a far greater rate than is conventional accelerator technology, and it is not inconceivable that the sorts of laser necessary to generate the particle beams necessary for cancer therapy could soon be small enough, and cost-effective enough to be widely available (how widely, of course, remains to be seen).
Also, it's much easier to manipulate the laser beam towards the patient (where it can be used to generate a particle beam within a very small space ... viz. the 3.3cm GeV accelerator result that has made the headlines recently) than to do the same with a conventionally produced particle beam.
How soon will this happen? It's difficult to say. My guess is of the order of a decade or more (but this is only a guess). A substantial increase in the average energy and decrease in the energy spread of the beams produced will be necessary, but progress in both is still very encouraging. And I wouldn't be surprised if clinical trials of the use of electron beams produced in this way for treating shallow tumours, began in the next few years.
But cancer therapy is not the only possibility, of course. As has already been mentioned, the beams produced by these devices could readily be used for making medical isotopes. And they can also be used for generating short bursts of X-rays, which have all manner of uses in biological and medical research (viz. the current, and increasing, buzz about Free Electron Lasers, used also for pulsed X-ray generation, but developed out of conventional accelerator technology ... another unanticipated app from fundamental physics research).
And last, but certainly not least, it promises an entirely new frontier for learning stuff about the Universe. And surely that in itself is enough, isn't it?
Joe Dutch