Half a croissant, on a plate, with a sign in front of it saying '50c'
h a l f b a k e r y
You think: Aha! We go: ha, ha.

idea: add, search, annotate, link, view, overview, recent, by name, random

meta: news, help, about, links, report a problem

account: browse anonymously, or get an account and write.

user:
pass:
register,


                                                                                                                                               

Three Fusion Reactor Variations

Combine multiple techniques
  (+2, -1)
(+2, -1)
  [vote for,
against]

Synopsis:
A number of different methods have been suggested and tried, with respect to the goal of achieving controlled nuclear fusion for power production. It seems to me that some of those techniques are "complementary", such that if combined in an overall system, the whole would be a more effective means of reaching the goal. The particular techniques under consideration here include high-pressure hydrogen gas, laser ionization, solid-hydrogen pellet acceleration/collision, and theta pinches.

The Details Begin:
NOTE: I shall be using the word "hydrogen" herein a great deal, while the particular varieties involved are probably going to be deuterium, or a deuterium/tritium mixture, or even a deuterium/helium-3 mixture. But "hydrogen" is encompassing enough, and simpler to write. Anyway, the quest for controlled nuclear fusion has been taking too long, partly because the task is not simple, but also partly because resouces devoted to the goal have been divided into umpteen different schemes, all of which are somewhat promising, but few of which seem able to be sufficiently workable in the final scaled-up form of a power reactor. I am bothered by the fact that people know full well that many inventions come about from different things being combined together, yet as far as nuclear fusion research is concerned, the researchers are largely divided into camps, each of which thinks its own approach is the One True Way. There are the magnetic confinement people, the electrostatic confinement people, the inertial confinement laser-blast people, the inertial confinement electron-blast people, the inertial confinement sonic-blast people, and so on, and so on, and so on. Bah!

Some History:
It was known back in the 1950s that the temperatures needed for nuclear fusion were extreme. There was an obvious problem in trying to "hold onto" multimillion-degree matter, while trying to force atoms to merge together. Still, it was known that at high temperatures atoms shed electrons and matter becomes a mixture of bouncing ions -- all of which are electrically charged and can be manipulated by magnetic fields. More, a plasma can also conduct electricity, and that electric current also generates a magnetic field. This magnetic field can squeeze or "pinch" the plasma, making it more dense and making fusion more likely. Unfortunately, the "pinch effect" tended to pinch the plasma unevenly, causing, for example, a pinch of the plasma into two separated blobs -- which breaks the flow of electric current and terminates the magnetic field that does the pinching!

Well, an alternative to the simple pinch was to generate the squeezing magnetic fields using ordinary external wiring. This quickly evolved into a huge curved conductive piece of metal (a "single-turn coil"), into which an enormous amount of current was dumped from a giant bank of capacitors. The volume of plasma within that "coil" became brutally squished to very near the fusion point; some of the first recorded controlled fusions, in fact, came from this "theta pinch" device. But it had its own flaw, in that to operate most efficiently, it needed to START with a DENSE volumous plasma -- something which still cannot be contained today with external magnetic fields.

Next, the inertial-confinement people deal with extremely dense plasmas, which they make on-the-fly from small amounts of solid or liquid hydrogen-containing substances. The blast of energy that that small volume of material receives is sufficient to cause compression and heating, ionization, and also some fusions. These researchers mostly have the problem of trying to apply that energy to all sides at once, perfectly evenly, of the small volume of material, lest it be kicked sideways (out of the center of the reaction chamber) and impact/damage their equipment. And, of course, small volumes of material lead to small amounts of fusion, so far insufficient to pay for the energy-blasts.

Perhaps you can now see the gist of what I am about to suggest here: The inertial confinement approach should be used to generate a decent volume of dense plasma, and the theta-pinch approach should then squeeze that dense plasma to the fusion point. Some of the details that I am going to present, however, you may find a bit surprising, especially if you are already familiar with the many existing approaches to controlled nuclear fusion power, so please bear with me. :)

Start With A Cylinder...
In essence, a single-turn theta-pinch coil is the body of a simple cylinder, with a single slice down its length. Electricity is fed into the cylinder all along one side of that slice, and after it flows around the body of the cylinder, the current flows away from it all along the other side of that slice. The Greek letter Omega (capitalized) looks something like a cross-section of a theta-pinch cylinder, including attached electric feeds. Note that the overall orientation of this cylinder -- horizontal or vertical -- will depend on choices made as this description continues.

The fact that this cylinder has a slice down its length means that if we want to use it to hold a vacuum (the typical environment for controlled-fusion plasmas), then we have to seal it (and, of course the ends of the cylinder) with some sort of nonconducting material. Glass, ceramic, or some other stone-like substance will probably do fine (have to watch those thermal expansion coefficients of differing materials, but they do that already, in such mundane realms as light-bulb manufacturing).

Add Some Hydrogen-Rich Material...
This could be as simple a thing as injecting a frozen-solid-hydrogen pellet (vertical cylinder). Then we blast it with a laser from each end of the cylinder, which plasma-izes the pellet, after which we SQUISH it with the main theta-pinch pulse.

Or we could take fresh liquid hydrogen and use magnetism to separate the naturally magnetic "ortho-hydrogen" form from the naturally non-magnetic "para-hydrogen" form. (Background Info: Ortho- and Para-hydrogen molecules are distinguished from each other by the way the two electrons are mutually oriented with respect to a property called "spin". Each electron-spin is associated with some magnetism; if the two electrons spin oppositely, the magnetism cancels and the result is para-hydrogen. If they spin the same way, the result is the slightly more energetic ortho-hydrogen molecule. At room temperature, there is enough ordinary thermal energy so that a significant percentage of hydrogen is ortho, but that percentage gradually diminishes at liquid-hydrogen temperatures, as ortho changes to the para form.) With our fresh liquid ortho-hydrogen, we now freeze it into pellets, and immediately use these pellets two at a time. We put them into coil guns! We magnetically accelerate them to perhaps a hundred kilometers per SECOND, and shoot them into our cylinder (horizontal orientation), directly at each other. They collide (and cancel their overall motion) most spectacularly, almost instantly converting into a single dense plasma blob-- every molecule is moving at plasma-temperature-speed, see! -- which we immediately SQUISH with the main theta-pinch pulse. The reason for this variation is that magnetic acceleration is much more energy-efficient than the process of creating a laser pulse, and ALSO more efficient than the process that converts laser energy into hydrogen plasma.

Or we could fill our cylinder with pressurized hydrogen at ordinary temperature. If we wanted to be extreme, we could pressurize it until it becomes liquid, but I doubt that this will actually be necessary. Now we shine an ultraviolet laser beam down the middle of the cylinder. This not-very-powerful beam has to be UV light of a particular frequency (the primary "Lyman" spectral line). When a UV photon of this frequency is absorbed by a hydrogen atom (and this particular frequency is easily absorbed), the hydrogen instantly ionizes. The net effect of shining this UV laser beam down the axis of the cylinder is that we create an ionized pathway, which is able to conduct electricity. Now we discharge a small bank of capacitors, creating a minor artificial lightning bolt through the hydrogen in the cylinder, which of course follows that ionized pathway. Since lightning is always accompanied by thunder, and since we are involving highly pressurized hydrogen here, the "boom" is going to be quite notice-able. This "boom" will ECHO off the walls of the cylinder!!! -- and form a sonic compression wave that will naturally squeeze the hydrogen at the central axis of the cylinder. We can add another UV pulse and another capacitor discharge -- none individually need to be very powerful, but the resonant accumulative effect is going to cause a significant volume of very hot dense plasma -- which of course we SQUISH with the theta-pinch pulse. (For anyone who thinks that this whole reactor might explode like a bomb, well, I suppose it will depend on just how compressed the hydrogen is, in the cylinder, before lighting the laser. Fusion reactions ARE damped quite easily, due to ordinary matter being extremely cold, relative to the temperature required for nuclear fusion. Still, if it DID explode, you couldn't say that this technique didn't pass break-even, could you? :)

Extract The Energy:
The first two notions will require that cylinder be lined with heat-absorbing fluid, which in turn flows to a heat-exchanger to generate steam for turbines. They also have a comparative weakness with regard to neutron-absorption; they will become radioactive more quickly than the compressed-hydrogen cylinder (hydrogen is a GOOD neutron blocker!) Also, the third proposal offers a one-step way to extract energy, because instead of using an intermediary heat-transfer fluid, that tank of compressed hydrogen merely needs to have some plumbing leading to a heat-exchanger, which makes steam for turbines. Also, of course, we will want to filter out waste helium-4, before returning the fuel to the reactor cylinder.

Vernon, Apr 26 2004

Similar to this? http://adsabs.harva...1975pwh..meet.....T
[Vernon, Oct 06 2004, last modified Oct 17 2004]

Some hydrogen properties http://www.uigi.com/hydrogen.html
Hmmm...this describes ortho-hydrogen in terms of proton spins and not electron spins. I think that either way qualifies. [Vernon, Oct 06 2004, last modified Oct 17 2004]

Ortho-hydrogen http://www.site.uot...html#ortho-hydrogen
Pretty detailed, and includes link to a para-hydrogen page [Vernon, Oct 06 2004, last modified Oct 17 2004]

Magnetism and hydrogen http://lemp.snu.ac.kr/work/jp535.pdf
Looks like it might be worth spending some money on, after all. [Vernon, Oct 06 2004, last modified Oct 17 2004]

Inertial Confinement http://hyperphysics.../nucene/finert.html
Basic info [Vernon, Oct 06 2004, last modified Oct 17 2004]

CECP Fusion website http://fusedweb.pppl.gov/CPEP/chart.html
The poster is an image map -- interesting stuff about binding energies, and progress in plasma quality. [dpsyplc, Oct 06 2004, last modified Oct 17 2004]

Virtual Tokamak http://w3.pppl.gov/~dstotler/SSFD/
[theircompetitor, Oct 06 2004, last modified Oct 17 2004]

More Fusion Background info http://www.jet.efda...sson/pages11-20.pdf
Including ancient pinch effect stuff. Note first couple pages of this .PDF file seem to be blank. [Vernon, Oct 06 2004, last modified Oct 17 2004]

Coil gun description http://en.wikipedia.org/wiki/Coil_gun
A long multistage design will be needed, to accelerate pellets to 100km/sec (and we need two of them) [Vernon, Oct 06 2004, last modified Oct 17 2004]

Hydrogen Spectra 1 http://www.colorado...tumzone/balmer.html
A nice description, mostly about the visible spectral lines in the Balmer series. [Vernon, Oct 06 2004, last modified Oct 17 2004]

Hydrogen Spectra 2 http://www.science..../c120/hspectra.html
The Lyman series of spectral lines is entirely in the ultraviolet. Studying such spectra led to the development of Quantum Mechanics. [Vernon, Oct 06 2004, last modified Oct 17 2004]

National Ignition Facility (USA) http://www.llnl.gov.../project/index.html
The latest in the pure laser implosion approach. [Vernon, Oct 06 2004, last modified Oct 17 2004]

Theta Pinch stuff http://topics.aip.org/5255E_FS.html
More than I expected to find, actually. [Vernon, Oct 17 2004]

Omega http://www.nemitz.net/vernon/Omega.jpg
The Greek letter, capitalized form. In this image, at the bottom-left and bottom right, are two short vertical lines that are not present in many other representations. [Vernon, Oct 17 2004]

Sonic Resonance and fusion http://www.halfbake...on_20Steam_20Boiler
Another HB idea, specifically focused on using resonance to achieve fusion. [Vernon, Oct 17 2004]

Laser Amplification http://www.halfbake...idea/Hyper_20Lasers
Ordinary lasers are pretty inefficient. This may be a significant improvement [Vernon, Oct 17 2004]

Nuclear Isomer battery https://en.wikipedi...r#Nuclear_batteries
In development. [8th of 7, Apr 28 2017]

Old Mac Commercial https://www.youtube...watch?v=9IHnP67G-jA
As mentioned in an annotation. [Vernon, Apr 30 2017]

[link]






       how did i know this was a Vernon idea before i reached the bottom?
engineer1, Apr 26 2004
  

       [Ling], thanks for the link, but actually I think that is a different notion altogether.
Vernon, Apr 26 2004
  

       The inventive method here is to combine so many esoteric phenomena that it is impossible to say it won’t work (without spending billions).
ldischler, Apr 26 2004
  

       [ldischler], it is not necessary to spend billions to find out if some of these combined methods will work. A few million for two different sizes of models, from which we can gather data that can be used for full-scale-up calculations. And, I've just encountered a Web page that claims that ortho-hydrogen is not affected by magnetic fields. I'm looking for verification or rebuttal of that -- but obviously if verified, then one notion can be dropped before investing hardly anything!
Vernon, Apr 26 2004
  

       One notion can be dropped, you say. Hell, you’re not going to get any funding that way.
ldischler, Apr 26 2004
  

       Ah, but now see the "Magnetism and hydrogen" link. Heh heh heh...
Vernon, Apr 26 2004
  

       I thought this was going to be a radioactive romance movie, something along the lines of "Three Weddings And A Funeral".
normzone, Apr 26 2004
  

       /then we have to seal it (and, of course the ends of the cylinder) with some sort of nonconducting material. /   

       I propose rubber. Happy to help!
bungston, Apr 26 2004
  

       talkamak too much
theircompetitor, Apr 26 2004
  

       We should all chip-in and make Vernon a piezoelectric keyboard. This would produce plentiful net-gain energy for all.
Laughs Last, Apr 26 2004
  

       hmm six fish and nary a detracting comment. i know practically nothing about this field (i know what fusion means) so i need someone to tell me why this wouldn't work. speak up boners. (snigger)
stilgar, Apr 27 2004
  

       /This "boom" will ECHO off the walls of the cylinder!!!/ Not if all the plasma is confined in the centre of the tube it won't. To echo off the walls, the plasma needs to make contact with the walls. When you get the plasma, at 100million degrees C touching the container material, then the walls will ablate, and the plasma will cool down.   

       Another thing... the magnetic field generated by the current going around the omega-shape will be parallel to the length of the tube, right? Which will tend to confine any movement away from the axis of the tube, but will not have any affect on movement along the axis. At such high temperatures, I would imagine that diffusion would happen very quickly, and your plasma is going to be spilling out of the ends of the tubes. Unless you've bunged them with [bungston]'s rubber suggestion.   

       And another thing! You're firing two bullets of frozen hydrogen at each other at a hundred km/sec. What if you miss?   

       Sorry to be so negative. Maybe I just misunderstood it...
spacemoggy, Apr 27 2004
  

       Why a tube? Would a Torus not work better? I haven't got a clue about much of this btw.
silverstormer, Apr 27 2004
  

       [spacemoggy], you are wildly mistaken in at least part of what you wrote. A lightning bolt (even a small artificial one) is plasma surrounded by gas. The plasma expands and quenches, amidst the gas, well before hitting the walls. So the "boom" is GAS expanding, and the walls will survive. Next, the echoing "boom" will concentrate energy once again at the central axis of the cylinder, where a plasma may reform (intentionally aided by another shot of the UV laser, and another capacitor discharge). Note that after several such cycles, when we have decided that resonance has let us accumulate enough hot dense plasma, THEN we fire off the main theta-pinch pulse, and ONLY then is when we will see 100million degrees. Do note that the theta-pinch will squeeze the plasma MUCH FASTER than the pressurized gas in the cylinder can move to occupy the axial space that the plasma had initially occupied. This means that our fusing plasma will momentarily be surrounded by vacuum!!! The fusions will be over-and-done-with well before the now-expanding plasma collides with the axis-bound pressurized gas. Again quenching of the plasma will occur -- mixing with fresh fuel! -- and again a "boom" of thunder will signal the beginning of the next cycle.   

       With regard to the axial nature of a theta-pinch, yes, the open ends are problematic. But the pressurized-cylinder notion allows us to decide the precise length of our lightning bolts (only between interior-mounted electrodes, see?). This means that any plasma expanding axially, due to theta-pinch, will run into gas and be quenched before encountering the ends of the cylinder, and thus those ends are protected. Mostly, though, inertia will prevent much axial motion of most of the plasma.   

       Regarding the other design using two colliding pellets, ensuring the two coil-gun barrels are exactly aligned is one of the things that low-power laser beams are good for. See any modern construction site.   

       [silverstormer], a torus could indeed be superior to a cylinder, with respect to the compressed-gas version. The other two versions need access to the middle, from both ends, however. (And the third one benefits from straight UV laser beams and lightning bolts, so curving those might be a bit difficult. But with mirrors and multiple elctrodes, we can do a polygonal plasma ring inside the torus...) Thanks!
Vernon, Apr 27 2004
  

       Well at least vernon added a sumery, and made it shorter!
my-nep, Apr 27 2004
  

       Combining all these different technologies reminds me of what a co-worker used to do—“loading an experiment for success.” Of course, that never worked, because the only things that combined with any regularity were the deficiencies.
ldischler, Apr 27 2004
  

       [ldischler], I think you are being unduly pessimistic. It indeed is known that a theta-pinch works most efficiently if it can start with a dense plasma, and we do indeed know of ways to make dense plasmas. Go ahead and find the deficiencies there!
Vernon, Apr 27 2004
  

       /[spacemoggy], you are wildly mistaken in at least part of what you wrote./   

       Not for the first time, [Vernon]. Thanks for answering my points. I still don't think it will work, because fusion never works, but if it's worth wasting taxpayers money on tokamaks, then I say it's worth wasting taxpayers money on this! Croissant for ya.
spacemoggy, Apr 27 2004
  

       It does seem reasonable to expect that a net-gain fusion process will require multiple steps, not unlike other chemical processes. It is hard to imagine why the fusor-heads would be insisting on a one-fell-swoop method.   

       It is also hard for me to understand why an Omega shaped device would be called a Theta Coil. Who does that?   

       Your techniques will require some amazingly good timing. Fortunately, the good people at Nintendo are getting to work on second generation expert button mashers.
Laughs Last, Apr 27 2004
  

       [Laughs Last], "amazingly good timing" is actually ho-hum old-hat stuff at any modern particle-accelerator facility. Computers keep track of it all, and control many time-critical actions....   

       Regarding the origin of the term "theta pinch", I can't say for sure. But I would expect it has something to do with the high-density mathematics that first described it.
Vernon, Apr 28 2004
  

       Folks, I have changed the title of this Idea (from "Proposals" to "Variations") because it really is about variations on a theme. If they had really been different enough for separate proposals, then I probably would have written 3 separate posts.
Vernon, May 04 2004
  

       What happened to Keep It Sweet & Simple? We already have a working reactor. 93 megamiles provides barely adequate containment for radiation that fuels an incredibly complex biotic energy conversion system that our ancestors have used for millions of years. In what way is this idea an improvement?
hardtack, May 19 2004
  

       [hardtack], solar energy arriving at this planet is mostly consumed by green plants -- and we have to LET it mostly be consumed by them, lest we suffer oxygen shortages. So, the more of the Earth that we cover with solar cells, the less we can have of forests, cropland, etc. This means that if we want our energy-intensive civilization to grow (or even to become fully developed all over), we absolutely need more energy than we can get from the Sun. AND we have to be careful about not heating up the planet while we do it (Beamed-from-orbit solar power would be BAD from that viewpoint).
Vernon, May 19 2004
  

       i agree with the idea of combining approaches: instead of laser-implosion of fuel pellets, what about muon-catalysed implosion? multiple beams of muons catalysing fusion in the outer layers of the pellet; the resulting implosion triggering fusion in the remaining fuel - thus achieving breakeven. wouldn't have to worry about muons 'sticking' to reaction products
philmckraken, Jun 07 2004
  

       [philmckraken], sorry, but as soon as muon catalysis was first discovered (in mid-1950s), they wasted no time looking to see if it could work in power plants. The problem is that it takes roughly 200Mev (million electron-volts) of energy to create a muon (given 100% efficiency), and D+T fusion releases about 17Mev -- and a muon is an unstable particle that has a lifetime of 2 microseconds. How many fusions can a muon catalyze, in its lifetime, to pay for its manufacture (including inevitable inefficiencies)? Not enough! (by a factor of five or six, if I recall right). Alas!   

       Now actually there is a ray of hope here. See, in ordinary liquid hydrogen (where muon catalysis was first discovered), the atomic nuclei are some distance X apart, on the average. Well, the number of fusions that a muon can catalyze can be seen as a consequence of how far a muon can travel in its lifetime, and how many nuclei it can encounter within that distance. Thus, consider an already imploded pellet (by such standard means as a laser blast), in which that distance X between nuclei has been reduced by, say, a factor of ten...this would NOT necessarily be enough implosion for fusion to be a natural result, but it IS enough so that any injected muons can now catalyze enough fusions to pay for their manufacture!
Vernon, Jun 07 2004
  

       [philmckraken], please accept my apologizies for not being awake enough to click on "Annotate" instead of "Delete". If you can restore your message, please do!   

       Still, since I did want to annotate, if follows that I managed to read your message first, and noticed that you stressed something in your previous anno, about using beams of muons to cause a pellet to implode. My intuition is telling me that that's too many muons, to be able to get enough fusion out of the pellet to pay for making them. My intuition could be wrong, though.   

       In terms of combining ideas to achieve useful fusion power, I have in years past thought about adding muon catalysis, and somehow didn't recall it when originally posting this Idea. Yet that is why I could so easily describe, in my prior anno, trying for a lesser squeeze of the fusion fuel, and then injecting just enough muons for catalysis to act as a kind of "spark plug" to set the fusion reaction off.
Vernon, Jun 08 2004
  

       [vernon] snicker! *recalls far side cartoon of boy at the school for gifted children trying to push open door that reads 'pull' *... as you know, the object of laser implosion fusion is to get as much energy in as short a time as possible into the fuel pellet before it simply melts away. beams of muons catalysing fusion in the surface of the pellet would seem to be more efficaceous as the 1st step in triggering fusion in the remaining fuel (which will be the bulk of the pellet). we are not so concerned about the well-known problems of Muon Catalysed Fusion (MCF) because we are not using MCF to do the whole reaction, just to start it. with all due respect, intuition is not sufficient to determine the validity of our little thought experiments; someone would need to crunch the numbers. unfortunately however much detail of laser implosion is classified due to its application to nuclear weapons design.
philmckraken, Jun 08 2004
  

       [philmckraken], the object of laser implosion (or any other method of pellet-zap) is to get a lot of energy into the SURFACE of a pellet, so that that surface explodes OUTwards -- and Action=Reaction therefore causes the rest of the pellet to implode. I could imagine that a pellet be coated with a special absorbant material, just to help that initial explosion.   

       Now, I see that you are intending that the muons cause fusions at the surface of the pellet, so that those fusions become the source of much of that initial burst of explosive energy. Allow me to express some doubts as to how well that intention can be fullfilled....   

       Consider original muon catalysis in more detail, please. The muons that were created via collisions with particles inside a liquid-hydrogen bubble tank, they were moving rather slowly. They encountered hydrogen atoms, and due to various physical properties, were able to bully aside the elctrons orbiting those atoms, and take their places. The resulting "muonic hydrogen" atoms are about 1/200 the size of ordinary hydrogen atoms. Such a muonic atom is a great deal denser than an ordinary hydrogen, and a whole muonic atom is able to plow right through the comparatively wispy electron shell of a neighboring ordinary hydrogen. This lets the muonic atom approach the nucleus of the ordinary atom quite closely, and as a result the two nuclei start to detect each other via the Strong Nuclear Force -- and so they fuse. Some of the released energy spits out the muon, ready to repeat the process.   

       NOW consider those fast-moving muons in your proposed implosion-beams. (They HAVE to be moving fast, to reach the pellet before their 2-microsecond lifespan is up!) To catalyze some fusions, each muon has to STOP moving quite so fast, in the frozen hydrogen pellet, and replace an electron in its orbit. How likely is that, right at the surface of the pellet? Certainly some will, but likely most will penetrate the pellet by a fair amount first. I submit that this will be the fatal flaw.   

       Now, consider the alternative, where we have a condensed and plasma-ized pellet, into we inject those fast muons. These do NOT have to replace electrons in orbit (not to mention that because the pellet is already plasma-ized, no electrons are in orbit!). All each muon has to do is pass between two about-to-collide-at-high-speed hydrogen nuclei -- large quantities of which will exist in this situation! The electric field of the muon will temporarily shield the two proton's electric charges from each other, allowing a closer-than-normal approach-during-collision. If close enough, then fusion results on-the-spot, and the muon is already on its way to get between another pair. No wasting of time orbiting and de-orbiting! Injection of a few muons should catalyze a rather disproportionate number of fusions! And sufficient fusions could yield enough energy to fully ignite the plasma-ized pellet....
Vernon, Jun 08 2004
  

       i defer to your wisdom, oh [vernon], you have shown my idea to be indeed half-baked. moreover, if you are right about muons catalysing plasma in such a fashion then that is brilliant. presumably there is research on this? (i'll have to bring my knowledge up to date). the problem with using both lasers and muons for pellet ignition is of course that you are raising the breakeven energy requirement. (i should very much like to add further annos when time permits *groans from other 'bakers*)
philmckraken, Jun 08 2004
  

       [philmckraken], thanks, but I was just putting some faith in statistics. I have no doubt at all that what I described can happen, and will happen, but I also have no idea how often it will actually occur. Experimentation is indeed in order!   

       Also, I have not necessarily raised the breakeven energy requirement that much. Consider the first variation of the overall Idea in the main text here: Zap a pellet with a measly two laser beams, and squish with theta pinch. IF one decides not to do quite so much squish as to directly pass breakeven, then perhaps that saved energy could instead be invested in a modest beam of muons, which would be injected just as the theta-pinch is activated.   

       Consider something I wrote in a prior anno about average distance X between hydrogen nuclei. Muon catalysis essentially reduces a local X by a factor of 200, so that two nuclei can fuse. Obviously we want about the same reduction in X, all through the plasma, for complete burning to occur. Now note again that a general reduction of X by ten or so should be enough to let muons catalyze enough fusions to pay for their manufacture -- any extra reduction is a bonus! I'm certain that a theta pinch can reduce at least two dimensions of X by 50 or so without straining much -- and in that environment, circling through the squeezed plasma around the axis of the cylinder, after injection through the slit in the side of the cylinder, muons should have a heyday (they CAN circle like that because of the way their electric charges interact with the magnetic field of the theta pinch).
Vernon, Jun 08 2004
  

       You'd think the most direct way of taking energy from the system for our benefit would be to directly extract the electrical charge of the plasma - directly - no conversion to steam, crankshafts, hamster wheels etc. Just dump the charge into something storage-ey. Maybe we need to design (in anticipation of such) very super supercaps, superbcaps, in fact, that could hold a city worth of electrical requirement in one transfer.
Ian Tindale, Apr 28 2017
  

       Baked. Nuclear isomer batteries.   

       <link>
8th of 7, Apr 28 2017
  

       Excellent! A MEMS reactor.
Ian Tindale, Apr 28 2017
  

       Actually, you've nailed it with the energy storage issue.   

       Your species lacks a cheap, safe, portable energy storage device with usefully high energy density - at a bare minimum, exceeding that of hydrocarbon fuels by several orders of magnitude.   

       There are plenty of ambient energy sources - renewables - you could harvest energy from, but the problem remains of matching production with demand.   

       Forget sources; for most applications, there's enough free stuff just lying around. All you have to do is store it until needed.   

       To encourage you, the only thing stopping the development of a practical directed-energy personal weapon is the lack of a suitable storage device.
8th of 7, Apr 28 2017
  

       We need more eels.
Ian Tindale, Apr 28 2017
  

       I've got a hovercraft full of them.
MaxwellBuchanan, Apr 28 2017
  

       Sorry, I couldn't resist this. I'm currently editing a novel for brevity and it's an exercise in doing this:   

       Synopsis: Various methods have been suggested and tried to achieve controllable nuclear fusion power generation, whereof several combined would seem to achieve this, such as high pressure hydrogen, laser ionisation, solid hydrogen pellet collision and theta pinches. Details: NOTE: "Hydrogen" herein means any of deuterium, tritium or a mixture, including a mixture of deuterium and helium-3. Seeking controlled nuclear fusion seems interminable due to the task's complexity and the innumerable somewhat promising but inadequately workable or scalable schemes, between which resources are divided. Whereas it's generally recognised that there are various ways of doing this and in other areas there's collaboration, this is not so with fusion. There's magnetic or electrostatic confinement people, the inertial confinement laser-, sonic- or electron-blast and so forth. Bah! Some History: It's been knosn since the '50s that extreme temperatures are needed for nuclear fusion. Maintenance of multimillion-degree matter while trying to fuse atoms is hard but it was known that hot atoms shed electrons and matter, becoming a mixture of bouncing ions -- all electrically charged and magnetically manipulable. Plasmas are moreover conductors and electric currents also generate magnetic fields. This magnetic field can squeeze or "pinch" the plasma, making it denser and making fusion more likely. Sadly the effect tended to pinch the plasma unevenly, causing, for example, plasma to split into two, breaking the current and terminating the magnetic field doing the pinching! Alternatively ordinary external wires could generate these fields . This quickly became single-turn coils - huge curved conductive pieces of metal into which an enormous amount of current was dumped from a giant bank of capacitors. The volume of plasma within was brutally squished almost to the fusion point; some of the first recorded controlled fusions, in fact, came from this "theta pinch" device. But it was itself flawed, in that to operate best it needed to START with DENSE large plasma, which even now cannot be contained with external magnetic fields. Next, inertial confinement uses very dense plasmas made on-the-fly from small amounts of non-gaseous hydrogenous substances. Blasts of energy at those small volumes of material are enough to compress and heat, ionise, and cause some fusions. The main problem is applying energy evenly all around the material, lest it be displaced away from the centre of the reaction chamber and impact/damage equipment. And, of course, small volumes of material mean small amounts of fusion, thus far involving net energy loss. My gist may now be apparent: inertial confinement should be used to generate a substantial volume of dense plasma, and theta-pinch should then squeeze that to fusion point. You might though be surprised by some details of what I will present though, especially if you already know the many existing approaches to controlled nuclear fusion power well, so please bear with me. :) Start With A Cylinder... In essence, a single-turn theta-pinch coil is a longitudinally split cylinder. Electricity flows down one side, then turns and flows down the other, somewhat like a capital Omega, including attached electric feeds. Note this cylinder could be horizontal or vertical overall, depending on choices made as this description continues. Having this split means it must be sealed with an insulator to hold a vacuum such as glass, ceramic, or another stony substance (must attend to the various thermal expansion coefficients, but this happens already in such mundane realms as light-bulb manufacturing). Add Some Hydrogen-Rich Material... This could be as simple a thing as injecting a frozen-solid- hydrogen pellet (vertical cylinder). Then we blast it with a laser from each end of the cylinder, which plasma-izes the pellet, then the main theta-pinch pulse SQUISHES it. Or we could take fresh liquid hydrogen and use magnetism to separate magnetic "ortho-hydrogen" form from non-magnetic "para-hydrogen" form. (Background Info: Ortho- and Para-hydrogen molecules are distinguished from each other by the way the two electrons are mutually oriented with respect to a property called "spin". Each electron-spin is associated with some magnetism; if the two electrons spin oppositely, the magnetism cancels and the result is para- hydrogen. If they spin the same way, the result is the slightly more energetic ortho-hydrogen molecule. At room temperature, there is enough ordinary thermal energy so that a significant percentage of hydrogen is ortho, but that percentage gradually diminishes at liquid- hydrogen temperatures, as ortho becomes para.) We now freeze the liquid ortho-hydrogen into pellets, and immediately use them in pairs. We put them into coil guns and magnetically accelerate them to perhaps a hundred kilometers per SECOND, shooting them into our cylinder (horizontal orientation), directly at each other. They collide (and cancel their overall motion) most spectacularly, almost instantly becoming one dense plasma blob-- every molecule is moving at plasma- temperature-speed, see! -- which the main theta-pinch pulse then immediately SQUISHES. This variation results from magnetic acceleration being much more energy- efficient than making a laser pulse, and ALSO more efficient than the process converting laser energy into hydrogen plasma. Or the cylinder could be filled with pressurized hydrogen at ordinary temperature. Going to extremes, we could pressurize it until it becomes liquid, but this is probably unnecessary. Shine an ultraviolet laser beam down the middle of the cylinder. This weak beam must be a particular UV frequency - the primary "Lyman" spectral line. Absorbing such a UV photon of this frequency (and this particular frequency is easily absorbed) instantly ionises it. The net effect of shining this UV laser beam down the cylinder axis of the cylinder is to create an conductive ionised pathway. Now we discharge a small bank of capacitors, creating a minor artificial lightning bolt through the hydrogen, naturally along that pathway. Since lightning is and thunder always occur together and this involves highly pressurized hydrogen, the resultant noticeable "boom" will ECHO off the cylinder walls, forming a sonic compression wave, naturally squeezing the hydrogen at the central axis. We can add another UV pulse and another capacitor discharge -- neither need be very powerful, but the resonant accumulative effect will create a significant volume of very hot dense plasma -- which naturally the theta-pinch pulse SQUISHES. (this whole reactor going off like a bomb may depend on how compressed the hydrogen in the cylinder is before lighting the laser. Fusion reactions ARE damped quite easily, due to ordinary matter being relatively far colder than the necessary fusion temperature required, but if it exploded clearly this technique would pass break-even :) Extract The Energy: The first two ideas need the cylinder to be lined with heat-absorbing fluid, in turn flowing to a heat-exchanger to generate turbine steam. They are also have comparatively weaker than neutron-absorption, becoming radioactive faster than the compressed- hydrogen cylinder, hydrogen blocking neutrons well! Also, the third proposal is a one-step way energy extraction technique as instead of an intermediary heat-transfer fluid, that tank of compressed hydrogen merely needs to be plumbed into a heat-exchanger, making steam for turbines. We will also naturally want to filter out waste helium-4, before returning the fuel to the reactor cylinder.   

       My version: 1152 words. [Vernon]'s: 1593 - so not really much shorter.
nineteenthly, Apr 29 2017
  

       If [Vernon] actually had anything to say, it would fit in 200 words, so I'll pass on this one.
MaxwellBuchanan, Apr 29 2017
  

       [MaxwellBuchanan], can you prove that anything needing said never requires more than 200 words? What about the fact that this Idea is actually 3 in one post --does that mean up to 600 words can be alloted for it (200 for each of the 3 ideas)? Well?
Vernon, Apr 29 2017
  

       Could you do it in 140 characters, times three?
Ian Tindale, Apr 29 2017
  

       I mean, I do sympathise because brevity is not my strong point either, but I have the excuse of having been trained to waffle for England by Warwick philosophy department. I was okay before that.
nineteenthly, Apr 29 2017
  

       Brevity, ah, soul…
Ian Tindale, Apr 29 2017
  

       // can you prove that anything needing said never requires more than 200 words? //   

       "Klaatu barada nikto" (Helen Benson)   

       "Now, Maitland, now's your time ! Up, Guards, ready !" (Arthur Wellesley)   

       "Nuts !" (Anthony McAuliffe)   

       "Weapon away" (Thomas Ferribee)   

       “Houston, we've had a problem here” (Jack Swigert)   

       .... want any more ?   

       NB Gr. "anything needing saying never requires ..."   

       // trained to waffle for England by Warwick philosophy department //   

       More deserving of pity than condemnation...
8th of 7, Apr 29 2017
  

       // can you prove that anything needing said never requires more than 200 words? //   

       Clearly there are exceptions. For example, it is hard to abridge a telephone directory in a useful way.   

       Howevertheless, if I were to read this and if it were understandable, I suspect I could say the same thing in 200 words.   

       As an example of how much useful information can be packed into 200 words: Broken flint has usefully sharp edges. Burning sticks can provide portable light and heat, and some food is better if you almost burn it first. Things are made of about 100 types of tiny particles about a millionth of a hair's-breadth across, called atoms, made of positive and neutral particles in the middle, and tinier negative ones around the outside; some numbers of the negative particles are preferable, and atoms swap or share electrons and get closer to a preferred number. Organisms evolve by random changes that, when beneficial, help the organism to survive and reproduce, perpetuating those changes. Heredity is carried by a polymer called DNA, made of two complementary strands of four building blocks, the order of which carries data. If two different metals are separated by a salty or acidic layer, they create a voltage. Silicon, alloyed with traces of impurities, can conduct or insulate depending on an applied voltage; this can be used to make miniature switches. All things can be represented by numbers, and all numbers can be represented as the on/off status of many switches. Most disease is caused by invisibly minuscule organisms; certain moulds produce substances that can kill many of these organisms.
MaxwellBuchanan, Apr 29 2017
  

       I'm impressed [MB]. Something to aspire to. I really wish I could get back to that degree of pithiness.
nineteenthly, Apr 30 2017
  

       Sounds like someone's been taking the pith out of you, [19th] ...
8th of 7, Apr 30 2017
  

       [MaxwellBuchanan], regarding "exceptions", consider "user manuals" for various things. How often do such things contain at most 200 words? Generally, the more details that need to be mentioned, the more words are required. I'm reminded of an old commercial (see "Mac" link) --still looks like more than 200 words are needed for the Mac....
Vernon, Apr 30 2017
  

       Internal combustion fusion engine [+]
Voice, Apr 30 2017
  

       Although, the iPad doesn't come with a user manual. *   

       * you can go and find one online and read the pdf if you like, but it doesn't come with one.
Ian Tindale, Apr 30 2017
  

       That's predicated on the very doubtful assumption that the sort of mouth-breathing dolt who buys/uses any apple product has the ability to read, and even less likely reason, rather than just banging on the funny little pictures on the display with their thick, hairy fingers with the long, yellow, dirty nails ...
8th of 7, Apr 30 2017
  

       (Sorry, prematurely pressed return) …and when I bought this iPad Pro, my second iPad, I found it was perfectly true - the previous experience of owning an iPad for the past six years enabled me to know exactly how to use this new iPad entirely without a manual. Except for Siri, as the old one never had that, so I still don't know how to use that. But, it has enabled me to not require the MacBook Pro I had relied on previously.
Ian Tindale, Apr 30 2017
  

       //consider "user manuals" for various things. How often do such things contain at mo[s]t 200 words?//   

       A "user manual" is an admission of design failure. It is just the manufacturer's way of saying "Look, we tried to design this thing properly, but we couldn't, so we'll have to tell you how to use it."   

       The only exception to this rule is things that can actually kill you, like JCBs. In those cases, the "user manual" exists (in its plastic wallet for all time) so that when you do kill yourself, the manufacturer can tell your next of kin's solicitor that you failed to read it.
MaxwellBuchanan, Apr 30 2017
  

       Most truly dangerous things don't come with any sort of instructions or labelling*, the logic being that "If you don't know EXACTLY what to do with this already, you shouldn't be handling it".   

       *Pad (Claymore) mines do generally have THIS SIDE TOWARD ENEMY stenciled on the nasty side ...
8th of 7, Apr 30 2017
  
      
[annotate]
  


 

back: main index

business  computer  culture  fashion  food  halfbakery  home  other  product  public  science  sport  vehicle