New lense tech increases focusing of beam 10x.

It may be difficult to separate "theory" from "application," but let''s see if this helps facilitate the discussion.
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New lense tech increases focusing of beam 10x.

Post by Mike Beauford »

Has anyone had a chance to look at this. I was wondering if it would be applicable to applying to a cylindrical fusor? It talks about a way to focus beams, specifically for now microwave to be 10x sharper way to focus a beam. Just curious.

http://technology.newscientist.com/arti ... power.html
http://www.sciencemag.org/cgi/content/a ... 0/5875/511

Mike
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Re: New lens tech increases focusing of EM beam 10x.

Post by waltsphotos »

After reading about these "plate" lenses, they would likely only work on electromagnetic feilds. Ion focusing would be in a different league. I think this may have possible aplications in laser driven IEC fusion.
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Re: New lens tech increases focusing of EM beam 10x.

Post by Mike Beauford »

Hi Walt,

My impression is that this can be applied directly to focusing an ion beam to a point. An ion source can be focused using an Einzel lens, which at its simplest form uses a 3 element lens, consisting of 3 cylindrical tubes with varying voltages applied to each of them. What they are proposing is a single lens with a small aperture that uses a set of charged capacitors arrayed around the aperture hole to focus the beam past the diffraction limit. At the very least, I would expect it to increase the neutron count for people using ion sources because they could focus their ion source better. Of course as always, as Richard says, this rolls glibly off my tongue, and the amount of effort involved to use something like this is not trivial.

Mike
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Re: New lens tech increases focusing of EM beam 10x.

Post by Richard Hull »

Focusing bulk, charged matter is a whole different beast from focusing massless, uncharged photons or EM radiation. Focusing matter is in effect, turning it and that takes energy proportional to that which is turned and, currently, the structures are somewhat large for doing this electrostatically.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
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Re: New lens tech increases focusing of EM beam 10x.

Post by DaveC »

Richard is correct.

Focusing photons (Bosons) at high efficiency, is limited by the wavelength. Both this superlens system and older confocal, sub-Rayleigh focussing, while possible is extremely inefficient. Perhaps 1 part per million throughput. But nevertheless, very high spatial resolution can be achieved, with the proper signal processing... sensitive enough detector and enough time.

But charged particles (Fermions) are another breed of cat. Here the energy exclusion principle applies... you cannot have two particles with the same energy in the same place at the same time - which is what "focus" amounts to -, therefore, to focus ions to a very small spot, means large radial forces... to compensate for the Coulomb forces.

In the simulation programs, Simion 7 or 8 or others, you can model these effects and see that there is a very significant repulsive effect that sets in when total charge exceeds say 1E -15 Coul. As the particles approach, (we all know this, don't we?) the forces build until the incoming (sidewards or radial) kinetic energy is balanced by the potential (electrostatic) energy of the group of charged particles. At that point the inward motion comes to a halt and reverses direction.

In order to get the tight focus needed for a fusor to work, one needs quite a lot of sidewards energy, so to speak. Thinking of this as a vector diagram, the sidewards velocity has to be quite large, about as large as the incoming velocity... This makes the angle of approach have two equal components, giving a resultant direction or convergence angle of 45 degrees.

Thinking of this as a lens with a 90deg (2x45) cone angle, we see this would be an extremely low f/ number lens. ( f/ = 0.707 actually)..to speak in optical terms. This is a very "fast" lens, indeed.

When you step back and look at the spherical IEC fusor, you realize that it is exactly this sort of lens system, when it is working. The lack of tight focus (the image), comes partly from the irregularities of the inner grid field (the lens) , and mostly from the widely varying " object" distances at which that the ions are created.

Perhaps by borrowing the concepts of these super-lenses, one could implement it in an "electrostatic" embodiment for use with ions in the fusor. Clearly a rather different central electrode (lens) is required.

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Re: New lens tech increases focusing of EM beam 10x.

Post by Mike Beauford »

Hi Dave,

Yeah, in all my excitement, I forgot about the Coulomb forces. The best you could hope to achieve with a super lens setup would be to focus them as close as possible before the Coulomb forces start to take over. Still, I would be it would increase your efficiency somewhat.

Mike
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Re: New lens tech increases focusing of EM beam 10x.

Post by Richard Hull »

Increasing the efficiency of not only our fusors but for all fusion processes has been a 50 year+ task that has failed miserably and eluded the best minds and most well funded efforts. What looks like a scientific engineering effort has proven insuperable.

Richard Hull
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Re: New lens tech increases focusing of EM beam 10x.

Post by DaveC »

To Richard's point.... (and there has been a lot of discussion on this board in the past)...

It is useful to consider what it takes to "focus" anything. In ballistics, we call it aiming.
The best rifling and alignment of sights, scope and barrel, uniformity of charge, projectile size, shape, and etc.... produce the smallest cluster of impacts on the target, but the variance of impact site is never zero.

When it comes to colliding atomic sized particles, the Deuterium ion, in the fusor's case, there is the uncertainty on the atomic scale of actual position. Or from the quantum mechanical viewpoint, the wavefunction is distributed over a finite distance (the "size") but it describes a time and position dependent probability of the ion being found at any particular location.

Added to that, there is variation in instantaneous "charge" value. From a macroscopic standpoint, we speak of the "charge" of an ion as being....Q, a constant. But when we get to atomic distances, this is also some sort of time and location dependent value. The average is still the same, as is the mass of the ion, but where and how much there is, and even whether the charge center coincides with the mass center, on an instantaneous basis... (the time scale here is sub femto seconds... less than 1E-15 sec.) ... these are really difficult questions to answer.

So... when we try with a macroscopic sized array of electrodes to aim something with the above characteristics... it really isn't surprising that we can only do just so well. The latest He ion microscopy is able to image single atoms... to me this is an extremely impressive achievement.. and it bodes well for the tasks we have to accomplish in fusion.

The "collision cross section" data gives the probability that particles will collide, based on scattering of colliding beams, and etc. These relatively low probabilities of a collision, and their energy dependence (KeV) are hints of the more basic atomic scale uncertainty of something hitting something.

Going to a nano-scale array of lens material, actually seems to add further uncertainty to the result...because the fields around these tiny apertures and distributions of materials...( the mini capacitors spoken of in the article. ) are steeply varying in space, and rapidly varying with time.

We are used to speaking of average values of things... voltages, fields, surface configurations and the like. But atomic scale focusing, takes a quite different approach... and perhaps the time is getting right for some detailed discussions on how to do this.

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Re: New lens tech increases focusing of EM beam 10x.

Post by Dustinit »

Increasing the efficiency of not only our fusors but for all fusion processes has been a 50 year+ task that has failed miserably and eluded the best minds and most well funded efforts. What looks like a scientific engineering effort has proven insuperable.

Richard Hull


It seems almost every post that Richard feels compelled to proclaim the doom and gloom of the problem that some of us have the guts enough to 'attempt' to solve where all before have failed. I feel that is why most of us have collected, like ions in a well, on this forum in the first place.

The "I think I might be able to do it" attitude is worn down enough by friends looking at you strangely, thinking quaint or eccentric, when you tell them what you are trying to do.

Richard has a great deal of respect on the forum and deservedly so. But the incessant proclamations of a futile effort for cheap essentially unlimited power seems to me to be counter-productive to the group in general. Perhaps causing some to give up in disgust.

I prefer to think Richard has already solved the problem and broken unity and has been paid off by the oil companies with a residual to discourage further development.

We are all willing to accept the defeat that is surely coming, I just don't want to be continually told about it in a place where optimism and encouragement for task at hand should reign. We are all dreamers here. Don't keep waking me up.

On to more useful discussions,
The problem of focussing on the atomic scale with nanoscale devices doesn't seem to be a very useful endeavour unless you are dealing with a manipulable wave function which the particles don't seem to have, unless they are traversing a magnetic field and have coherence. There is a dipole moment that would be manipulable to some extent in an rf quadrupole but I feel would be space charge limited and would need to be segmented in order to accelerate the ions at the same time.
It works for a photon I would guess because it is essentially massless. The ions get harder to steer as the velocity increases due to their mass and the time spent within the steering field.
As the fields get smaller or the velocity increases the applied voltage (or current for magnetic) has to also increase by the same order to retain the same focussing ability. These voltages /currents (think isolation-insulation and heat dessipation) will become impractical with increasing velocity.
I feel these are the reasons we are confined to the macro world of focussing (thank goodness- I don't want to get into lithography).
But I am probably missing something as usual and would like to hear the constructive ideas of others.
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Re: New lens tech increases focusing of EM beam 10x.

Post by Richard Hull »

Live 50 years of your life hearing real soon now and seeing no results other than larger and more expensive fusion projects end in tears for the public treasure but receive enthusiastic re-assurances from those involved that the next new thing will be the winner. You might sour a bit, too.

One thing that cements the deal and pulls it out of the realm of dreams is actually doing fusion yourself, with your own hands, and seeing the returns with your own instrumentation.

We are in crunch mode, quad wise. Electricity will be the future when oil is just a memory and just feed stock for the plastics biz.

I say focus and confine away my good friends and hold your dreams close to you hearts for it is there they must abide.

Every party needs a pooper and every dream a wakeup call. I am forced to wear the gravity boots leaving others to drift off on the wings of their dreams.

Richard Hull

P.S. One heartening thing has occured that is a point in the direction of honor and "serious speak" on the part of the current spate of fusion researchers looking for billions to finish ITER. They promise no grid electricity for a foreseeable 30-40 year future from fusion, and this is assuming every thing with ITER goes off as expected and works swimmingly. They state that no electricity will be produced by ITER. If ITER works great then a small, non grid, electric test bed fusion reactor will be produced 10 years after ITER is totally successful. At least they are opening a jar of vaseline for us this time in the spirit of easing the pain of no fusion electricity for a good time yet again.
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
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Re: New lens tech increases focusing of EM beam 10x.

Post by waltsphotos »

I fall inline with Richard's Gravity boots thinking, most engineering ideas never translate to fusion even when they are designed for fusion.

I for one would like Fusion to become a reality but that is still far off. We need radical new ideas to increase fusion efficency by factors of 30x grounded by realistic engineering abilities and fact.

The fusor for one is in the order of 100 to 1000 times less efficent then what is needed to make it a power source (someone can do the math and put the exact number here)

So a 10x increase would be nice but even focusing a beam 10x better focus does not translate into 10x more fusion; or even a 10x increase in a chance for fusion. at best we might see a factor of 1.1x increase which is still at least 98.9x short of getting power. How much money was wasted geting 1.1x of increase? more then was worth the time and effort to get there, if your goal is power.

Now on a side note, Fusors are useful as Neutron and Proton sources in multiple industries, including: meterial testing, military, and medical (radiopharmaceuticals). In those applications a 1.1 or greater increase in efficency is of great advantage.
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Re: New lens tech increases focusing of EM beam 10x.

Post by DaveC »

There is an important point here, that "success" almost always has to build upon another "success". Desperation, sometimes.... in the scientific realm leads to some sort of intuitive leap that is successful.

For example, whatever may be the ultimate useful extent of quantum mechanics, it has been very very successful in providing insight to all sorts of measurable phenomena, that before Q-M were not able to be described by the physical processes, then known.

But, because someone else got desperate and had a bright idea, is NOT proof that you or I will also do that. And engineering types are generally a bit uncomfortable with this sort of thinking (in the abstract, at least)...despite having at times to resort to the same moves themselves, in order to salvage a project. Most everyone with work experience can cite an example of this.

While fusor designs that are built on this board fall short of :breakeven", by about 6 orders of magnitude, the proper approach is to whittle away at this deficiency by building on what we CAN do successfully.

So that 10X improvement, - which is no small achievement incidentally - brings us one order of magnitude closer. It also will introduce a new set of conditions and restrictions, and move the event horizon out another 10x. This is good. Very good. It truly does not solve the problem in one stroke, but it makes a big contribution.

Only pie -eyed dreamers would expect to solve this sort of problem in a single inspired stroke. (Of course, it may well be that just this sort of individual WILL solve the problem... so you pie-eyed dreamers out there... keep dreaming.. okay?)

Frequently, in my own limited experience, solutions to apparently insurrmountable porblems have come by doing the "end run"... non physics terminology for ... NOT solving THAT problem!! In fact a common technique we all use is to convert an unsolvable problem into one we can solve.

Now if I KNEW how to convert our present "problem" with the fusor (or for that matter any of these other, infinitely more complex devices...). into a solvable one, you may be certain, I would impose on your patience to present my new business card!!

So.... I think we should keep Richard's open-eyed realism in view and not complain about it, as well as the pie-eyed dreamers' wishful thinking, and not disparage it. Meanwhile, we try to do things that make sense to move forward. On one side is the unvarnished reminder of where we are. On the other is a vision of where we want to go. In between is the experimenters' workshop and laboratory. Here is where the "Rude Anvil of Fact" is located, and where the "down n dirty" slogging occurs that gets us through the swamp, and fends off the alligators.... etc and etc.....

Carry on... and Tally Ho... and all that... Cheers to all.

Dave Cooper
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