"Goldilocks" Planet Found, Could Possibly Support Human Life

Discussion in 'Astronomy, Exobiology, & Cosmology' started by TruthSeeker, Sep 30, 2010.

  1. ElectricFetus Sanity going, going, gone Valued Senior Member

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    Why would it be so hard?

    If an arc welder can do it so can this. The mechanics are the same as an arc welder with feedable electrode except the electrode is now made of uranium or plutonium and the hot vapors are shot into this hypercritical reactor. More so handling standardized sticks of metal will not be hard.

    The cryogenics in space will be needed anyway for the superconductors on the nozzle, so you should not consider it mass. Keeping the liquid hydrogen cool in interstellar space won't be a problem either considering the temperature of interstellar space is below the boiling point of liquid hydrogen. If the tank mass was so much greater with liquid hydrogen then it would not be us in rocketry as it is today!

    Are you claiming we would launch this thing from earth, are you insane? It would be built in space, regardless if it were to operate on water, ammonia or solid/LH2, and it structure would only need to handle the g-loads of the engines thrust which would be a fraction of earth gravity.

    As for the tanks remember that many would be needed, they would be very long to reduce internal volume below criticality and have to be positioned far from each other as well, tanks with that much surface area and structure is a lot of wasted mass. Even assuming ammonia could be used the ISP would not be increased much. Based on figures from soild core nuclear rockets ammonia would only increase isp ~20% above the use of water, liquid hydrogen though allows for 100% increase in isp (doubling)!

    No, the atoms heat them selves, its a nuclear reaction, ideally no boosting liquid would be add and the ship would operate off the impulse of the fission fragments alone, but hydrogen is needed to provide moderation and keep the whole thing from melting. As a result its necessary addition will reduce ISP and the less that can be added the better.

    A modern atomic bomb can do beyond 50%, why can't this?

    To handle plasma of this temperature and density, I don't think so! !

    Or solid state x-ray converters.

    And yet kerosene does it this as well but in space travel they have usually opted for hydrogen and lox for upper-stages because in space the extra ISP is worth it over the extra mass in tanking and plumbing.

    Yeaaaahh, you need to look up how much thrust can come from light, I want to see the numbers!

    It will be an extremely small pressure, and tracking won't be a problem a simple laser coms kit is all the ship will need.

    How silly, lets say I had a cherry bomb and could blow it up for thrust, now instead I keep it in a chamber and just us the light given off for thrust, dragging the weight of the fragmented cherry bomb with me, which is more efficient? The amount of radiative pressure you could get from the fission fragments is nothing compared to the pressure they them selves exert and as soon as they fission they become waste that must be jettisoned anyways, might as well jettison them with all the impulse they can provide.
     
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  3. dhcracker Registered Senior Member

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    Yeah... I still like project orion. However are we currently capable of building this nuclear rocket as described? I mean honestly it seems the larger yet simpler orion would be a better and faster bet.

    But then again I carry a blasting license and I blew up rock faces for a living for a couple years so I just like to make things go boom!

    I say lets build the fastest ship we can right now and send it to this system, maybe send a few of these ships out there RIGHT NOW why wait?
     
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  5. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Not hard robots put cars together. - It is just extremely complex, requiring adaptive AI and adds a lot of weight especially when compared to no robots.

    Robots trying to handle cold solid uranium and turn it into a very hot liquid and then a vapor aint very easy. - In fact, I not sure you can even do that on Earth with AI robots and in space the liquid U will break into spheres and drift where ever they like etc. That seems not just a silly approach, but totally impossible.
    The arc welder does this in a constant 1 G field so the liquid drops do not drift away in all directions as surface tension can hold them to the solid being welded. You are, by design, removing drops from the solid with very little gravity and/or converting the solid into vapor which will carry some of the current and magnetically interact with making a force on the vapor. There are at least a dozen different instabilities that will help drive either drops or vapor towards the weaker field areas.

    If you plan to melt the Uranium with and arc, as I assume, it had better be very stead DC as an AC component will cause eddy currents that be repulsive to the arc current a drive drops away from the arc. Etc. There will of course be different temperatures on different parts of the drop's surface so different vapor momentum flux acting on the drops to help scatter them too. This is all much more complex in space than you seem to realize.
    Sure I should consider it to be extra, un-needed, mass if my magnetic coil is made of #000 aluminum wire as I have suggested.
    True for deep space once you get it there BUT will be needed while on the launch pad and while receiving solar heat near until past Saturn. (The equilibrium temperature of sphere without any IR absorbing atmosphere like Earth has, anywhere inside Mar's orbit is much higher than liquid H2 - at Earth orbit distance form the sun it is about 250K from memory).

    H is used today because it is relatively cheap compared to more exotic fuels and with O2 it has high ISP, but not the highest if you can afford the exotic fuels. We are not interested in H for heat of combustion. We want H because at any temperature it has the highest average atomic speed. Your argument is completely irrelevant.

    Noting that it can be used in blimps would be a more relevant argument as there too it is not burned, but used because its molecular high speeds (for any given temperature) as molecules hit the wall of the blimp make the internal pressure need with the least mass. (I.e. H2 has great pressure for little mass.)
    Yes I was thinking in terms of less than 200 years but agree that some structural weight could be saved in the rocket its self, but about 100 times more mass and fuel would be needed to get the material there plus the robots / crews that would put it together, if the current space station is any guide. (I.e. compare the total weight of all the launches that have built it to the weight of the space station.) Perhaps when the moon has a self sufficient colony you could launch from there but even still launching the simpler lighter NH3 version would be better and cheaper.

    Again I don't want to go into internal designs now, but higher ISP only refers to the fuel or heated gas ejected.

    You cannot ignore the more complex (possibly impossible) problems and the great increase in weigh associated with cryogenic refrigerators and robots trying to keep control of cold uranium turning first into a liquid and then into vapor in a low G environment with strong, high-gradient, magnetic fields from the arc heater etc. melting the the uranium.

    Why not a simple system that just squirts a slightly super-critical emulsion away for the stationary boron films (on internal sheets and/ or wall of the emulsion tank?
    A pump, about the size of one used in a home fish tank, is all you need for the handling of the emulsion fuel. No robots, no conversion of solid uranium to liquid then to vapors, and the heaters, etc. for that.
    You could and a bomb is exactly what you would have even if only a few percent of the U235 reacts in a minute instead of in ~15 years when that same energy is released in a nuclear power plant.

    You don’t understand that the problem is to cool the exhaust gas down to a temperature / pressure region that even a 10 Tesla magnetic field could contain and shape into an directed KE beam.
    Not even 10 Tesla super conducting magnet field is going to handle the bomb of reacting more than a percent of the U235 in a minute or less. It is long way to the closest star. An atmospheric pressure plasma is much more than needed and easily contained / shaped into a beam by conventional magnets. With a steady one atmosphere pressure exhausting into vacuum you be near speed of light in less than a year (my guess) and that is an “Earth year” but only a few months for you on the ship.
    I am not familiar with them, but surely they need to be much thicker and very much heavier than solar cells (otherwise 90+% of the X-ray just pass thru.) But more serious objection it that the plasma which generates much in the way of X-rays, such as a dense pinch, cannot be contained, even with the best super conducting magnets.

    Again you are thinking in terms of an unusable bomb.

    To respond to rest of your post without quoting it:
    (1)I think kerosene is so much heavier that H2 that unless only a tiny amount of stored energy is needed, H2 is a lighter system even with its insulation and refrigerator.

    (2) Yes with photon from plasma the thrust would be tiny, I won’t do any numbers but only point out that no mass is expelled. Thus the total mass of a large ship like we are considering may be 100 time less at lift off. (I think that is the order of magnitude of gas mass to be exhausted vs payload / rocket shell weight for a trip to a star.) “Sunless solar sailing” may be the only way it is possible to go there.
    (3) Again I am guessing, but I think a laser beam coming towards earth would be as wide as the solar system when it arrives. Even it only 1% of that width, that is a huge power requirement at the transmitter. Most people have the false idea that lasers beam do not spread as the travel. They do, just much more slowly than an incoherent beam does.

    (4) Your cherry bomb analogy is irrelevant as it constantly used up mass. There is nothing but energy used up to sustain the photon flux. – not one gram need be used.
    Except for the possible error that it is the fission fragments that are radinating*, that is all true, but eventually you run out of mass (and had to lift it all off). It is impossible to use even 1% of the U235 as you are thinking in tems of an un-containable bomb even with 10 Tesla so 99% or more of what you throw out is still U235. Much better to convert 20% to energy and throw out that energy in a momentum carring photon beam. Hell if you want to include robots, let them reprocess fuel rods – at least we know they can do that on Earth and do not know they can controllably transform solid U235 into vapor jet, even on Earth, much less in space.

    ---------------
    *In the no or little mass ejected system, it is the O or N not fully ionized atoms that make many photons each even if they are being ejected and forever if the plasma is contained. Again you cannot just make a bomb (react more than 1% in less than a minute) so most of what is ejected is H plasma with very little uranium fission fragments in it. (99+% OF ALL the U leaving will be un-reacted U235 to avoid being a bomb.

    Again, you need to add a cooling mass to the flow to contain and direct it or else you do just have a fission bomb. Only by adding coolant can you react more than 1%. There is just too much energy release by U235 fission – It must be done slowly – I.e. a lot of coolant added to a very tiny amount of U235 reacting each minute..
     
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  7. AlexG Like nailing Jello to a tree Valued Senior Member

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    I think the Orion proposal was only for blasting out of the gravity well. As a deep space propulsion method, it has some drawbacks, including anykind of fine control and throttling back.
     
  8. ElectricFetus Sanity going, going, gone Valued Senior Member

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    Dude the AI is needed no matter what the drive system is, assuming it even gets there and did not need repairs during its centuries long journey what is it going to do there without some kind of intelligence?!? There virtually no remote controlling is possible from 20 fucking light years away! SO even if it was using your ammonia emulsion (emulsions of what? water soluble in ammonia!) nuclear rocket your going to NEED an AI, end of fucking story.

    its as easy as shoving a welding stick into an arcwelder!

    Its only liquefied and vaporizes in the reactor. Its like shoving sticks into a wood chipper.

    Probably because you huff glue and have no imagination! If a battle tank's autoloader can shove 120mm rounds into a cannon while the tank its bouncing violently over terrain, I think an autoloader can shove 20mm plutonium sticks into a reactor in space!

    Do I have to diagram this? sticks are shove in, melted via induction or arcing or what ever, vapor is accelerated to core via electrostatics, its not hard.

    Sound great to me, there already inside the reactor!

    what are you smoking?

    No that exactly relevant that why we use hydrogen, that why you wanted ammonia, for more hydrogen, to increase ISP. Jesus you just shot down your own argument!


    first, your not launching this thing from earth no matter what version
    second, robots and AI are going no matter what, unless we were sending humans and fat chance of that.
    third, your going to need superconductors for the nozzle
    forth, ammonia is not going to increase the ISP much over water and not going to dissolve the salts!

    no shit.

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    The cryogenics is not going to add significant weight, and will be needed anyways.

    inside of the reactor, the only thing need to be controlled is shoving in the uranium/plutonium.

    [quite]
    Why not a simple system that just squirts a slightly super-critical emulsion away for the stationary boron films (on internal sheets and/ or wall of the emulsion tank?[/quite]

    because of all the excess weight in useless mass in nitrogen and bormide... and emulsion of what?

    and then what going to fix the pump when it breaks down?

    exactly, its a controlled continuous nuclear expulsion, Zubrin him self stated that to achieve 3.6% the speed of light requires 90% U235 with 90% undergoing fission

    If it has to be cooled down then the whole design is infeasible, the need to speed is paramount.

    Well then why are we arguing the whole thing infeasible, shove it in Zubin face.

    When flying on pixie dust.

    think a thousand thin layers of foil, and the goal here is not containment just deflection.

    Only a tiny amount, relative to what? Kerosene is a viable rocket fuel because it volumetric energy density if far better then liquid hydrogen, that the reason kerosene is prefer for first stage fuel to reduce size while traveling through atmosphere, but in space hydrogen is king, highs energy density by mass, higher isp, ect.

    100 times less is a number, how the fuck did you come up with that!

    Laser coms between stars is a viable concept, there even a seti program looking for it, its quite possible in certain spectra to outshine the star once there with meager amounts of input energy.

    No shit

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    Aside for all the fissioning uranium!

    first off it this is true then just chuck the whole concept, nuclear salt rocket is not feasible, you just said so. Second there is no way in hell that 20% or so claimed in photons is going to provide any useful momentum

    anyone can transform metal into vapor jets, several technologies are reliant on it from vacuum plating to computer chip construction. Also the gas core nuclear rocket is reliant on what I'm talking about and nowhere have they ever said that melting/vaporizing uranium in space was a show stopper, or even a problem of the design.
     
  9. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    ElectricFetus:

    I will not reply point by point, but just point out some of your misconceptions:

    Originally you seemed to understand that one can not just shove the U235 rod into the reactor as you said:
    Then later you switched to describe the melting process to resemble a arc welder melting instead of a “small priming reactor” Now you are suggesting two different means of feeding U235 to the fission reactor:
    You said:
    You are still vague as to where the solid fuel rods become liquid , then vapor on their way to becoming a reacting fusion plasma.

    Your method (1) “Shove the rod into the reactor” will only quench the reactor. I told you (and you should already know) that any contact of the plasma with solid (or liquid) will quench the plasma in micro-seconds. I will now explain further why this is so: There is surprisingly little energy in the plasma even though it is very hot. This is because the particle density is very low. Even at the fusion core of the sun, where the pressure is very great, compared to anything man could dream of achieving, the particle density is less than in the air you breath! I forget the numbers, but guess that your fusion plasma would have about 6.23E14 protons /cc (to take a convenient number as in a mole there are 6.23E23 atoms so only 0.000,000,001 part of a mole evaporated from a solid (or liquid) during contact with the plasma will require each atom of the plasma to give up the ionization energy of the entering atoms just to remain as a relatively cold plasma.

    That is why the outer most parts of the magnetic field of controlled fusion devices often loop far away from the fusion plasma into or as a “diverter” – a high vacuum area. Just the out gassing from the vacuum wall due to radiation is a particle flux problem. The diverter magnetic loop into the high vacuum region diverts these initially neutral atoms from the vacuum wall along the field lines as soon as radiation ionizes them. You must keep even the tiny normal wall out gassing particle flux away from the plasma. Sticking a rod into the plasma reflects ignorance beyond description.

    SUMMARY for case (1): As I told you before, you will immediately quench the plasma if you try to stick a solid U235 rod into it.
    It ain’t at all like “shoving sticks into a wood chipper” or “shoving a welding stick into an arcwelder”

    Your case (2) with pre-reactor melter/vaporizer, fails for a different reason: The vapor is a neutral gas and will not respond to the applied electrostatic field as you suggest. Perhaps you will want to modify the pre-heater to make it into a plasma and use a divergent magnetic field* to accelerate the fuel in plasma state into the main reactor (not acceleration by an electro static field as the plasma also will not respond to that.) Alternatively you could use an AC field to induce eddy current in the plasma and try to repel it into the main reactor?

    I do not doubt that you can with an arc convert the solid U235 rods into first liquid drops then into a vapor, perhaps even a low temperature plasma. The arc current will make a very non-uniform magnetic field, from which the plasma will uncontrollably escape via one or more of the dozens of instabilities it knows. Thus I will assume that you only make a neutral vapor. Remember we are in a very low gravity environment. Thus the differential heating of the air (or any gas) will be a scattering wind, blowing and scattering the tiny drops as it thermally expands in all directions. If you say there is no atmosphere, then how does the arc pass? (An arc is an ionized path thur an atmosphere.) If you try to avoid arcs and use induction (AC fields) you have the eddy current reactions driving the drops in all directions.

    SUMMARY for case (2): It will not work even with the various modifications I have suggested to solve some of your more obvious conceptual errors.

    -----------
    *Plasmas are highly dia-magnetic and know dozens of instabilities with which to escape into lower magnet field strength regions. (Why the controlled fusion problem is more than 50 years old without a solution.)

    BTW, "AI" comes in many levels of complexity -Everything from the automatic setting of my digital camera's exposure to the complex system trying to adaptively handle solid U235 being transformed into a plasma in a low G environment, which for reason already discussed, is very likely an impossible task.
     
    Last edited by a moderator: Oct 13, 2010
  10. dhcracker Registered Senior Member

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    Robotic arc welding requires constant supervision and modification by a human, you have to be able to do that in real time. If the arc isn't working correctly you have to know right now, I think robots controling spaceships are still unpractical.

    And Alex why couldn't conventional rockets be used for fine control? Throttling back is done by turning the ship around, you have to shield the ship from radiation obviously if you have human passengers but other than that I don't see it as out of the realm of possibility.
     
  11. ElectricFetus Sanity going, going, gone Valued Senior Member

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    Of course its impractical, today, all of interstellar travel is impractical, today, that my point, even before we decide on a drive system the interstellar ship is going to absolutely need a level of automation that does not exist today!

    Billy T,

    No I'm not recommending shoving it directly into the reactor so any complaint of your is invalid on that measure, and the vapor can be made into an ionize gas with relative ease, it can be vaporized with simple heating like any metal spuddering system which operate in vacuums. but please take further issue with this reactor design with the nuclear engineers that have been advocating gas core nuclear reactors and rockets for decades now, they never seem to find the problem to be take solid uranium metal or uranium compounds and atomizing them before shoving it into their reactor designs.
     
    Last edited: Oct 13, 2010
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    Vacuum sputtering may be a good first step. Sputtering is slamming some some very energetic beam, perhaps of electrons, into the solid U235 to liberate tiny pieces. Then these very tiny pieces or only atoms must be charged and accelerated by a strong electric field with some focusing magnetic field shaping into a well defined beam. As they are charged they they can not cross the reactor's plasma confining field, so that charged beam must be neutralized, without it losing much energy or being spread much. That high velocity neutral beam of fuel can then get thur enough of the reactor's confining field before it is ionized to be then (as ions) trapped in the reactor.

    This is complex but not too hard if the fuel is one of the three hydrogen isotopes. And that is basically the plan for quasi-continuously fueling a stable fusion reactor, if one can ever be made. (Not lose its plasma via instabilities in less than a second.) Doing this to U235 atoms, i.e.making them into a neutral beam than can cross the confining field of a gaseous plasma fission reactor*** is at least conceptually possible but much harder**, but I don't think it has ever been done.

    -----------------
    *Good that you now recognize that is nonsense, but you did say:
    "Its only liquefied and vaporizes in the reactor. Its like shoving sticks into a wood chipper. " That is why I "complained." - Made a valid complaint explaining why that would only quench even a very hot fission plasma and certainly any colder one in the pre-heater you sometimes spoke of.

    ** In part because the charged U235 will never be stripped of all its bound electrons as the Hydrogen isotopes easily are (13.6ev is all it takes for complete ionization)

    *** You mentioned that people are trying to make a gaseous plasma fission reactor. I was not aware of that, so if you have a link please give it. As the energy density in a fission plasma would be more than 1000 times lower than in a conventional fission reactor, I can not see any motivation for even trying to make a unit which would be at least 1000 times larger for the same power out put and yet have all the hazards of any fission reactor.

    Final note:
    For more than four decades, I have not keep up with the field, in which I worked for a decade. I came to the conclusion ~40 years ago that the plasma was "smarter than man" in the sense that it knew more instability modes for escaping long-term confinement than man knew how to "stopper" all the instabilities. For more than four decades, my judgement has proven to be correct.

    My loss of interest in the controlled fusion problem was accelerated when the fast breeder fission reactor, FBFR, was shown to be feasible and economical. With it there is enough fuel for several thousand years. (I am not sure, and tend to doubt, that man will last that far into the future now that he can created very novel, living, contagious, pathogenic organisms.)

    Even if long-term confinement of a fusion reactor plasma is possible, it will never be an economic competitor with the FBFR which does not need strong expensive magnetic fields and complex, difficult refueling technology. (Just as now, ever decade or so, refueling is to exchange a few fuel rod units.) In ~50 years I have transformed from a great supporter, working in the field of controlled fusion, to a strong skeptic of it ever being a useful idea. Even before taking a job to work on controlled fusion, my Ph.D. research problem was plasma physic research. I was a stereotypical idealistic youth and now am a typical skeptical old man.
     
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  13. ElectricFetus Sanity going, going, gone Valued Senior Member

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    what confining field, you mean the field of the nozzle, which is not confining rather only deflecting the blast away from the nozzle wall and out into space? Considering the tiny area of the injector over the whole area of the nozzle, simple pressure of the injected mass is all that is needed to hold back the blast at that spot. And the magnetic field of the nozzle is all converging on that spot, so that the only spot for a beam of hydrogen and uranium to come out of, the beam its self would be allowed to diverge a lot as it travels down the expanding cone.

    Alot of things have never been done, the whole nuclear salt water rocket has never been done. We are talking in hypotheticals here.

    The misinterpretation was yours not mine. I never meant to imply solid fissionable would enter the core.

    GIYD

    Yeah that way extreme UV lithography does not work or predictions in plasma pinching are all wrong, oh what EUL does work (sort of) and plasma pinching has match theory so far, silly me! Maybe the problem is comparing a failed system like a tokamak with all plasma theory in general.

    Certainly not most existing sodium cooled ones!

    Unless they can make aneutratic reactors the size of gas stations, improbable but not impossible, consider research on dense plasma focus
    and before you start moaning like you do, seriously read about it first, it not an attempt to "contain" plasma, at least for not longer than a millionth of a second, and the reactors makes a lot of sense if they can defeat x-ray cooling and generate net positive power from each pulse that is.

    Probably because you people were working with Tokamaks all these years and thought magnetic confinement was all that ever was. Inertial, electrostatic confinement and hybrids of have barely been given any research at all compared to tokmaks and so after 50 years of trying to jam a square peg into a round hole you declare that nothing could fit in there.

    I don't count on fusion ever coming about, but I don't disregard it either.
     
  14. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    I don't know what GIYD is.
    I agree plasma pinch is well understood, but it is not as recent as you seem to think. In fact I used them and a lesser known, closely related azimuthal version* more than 50 years ago.

    Our small group at APLJHU was not trying to solve the controlled fusion problem. The US navy funded us as back then they thought they would be placing order for a fusion powered aircraft carrier in a decade or so. (One of APL’s main jobs was/is to oversee Navy contractors and that is what they wanted us to be in a position to do.) All the Navy required of us was that we both follow the larger efforts and also gain "hands-on" experience in smaller experiments. My efforts centered on how to inject plasma into a containment device, which was a mirror machine, so injection via the axial end escape path was planned. (Then the mirror machine's field would be strengthened during the "plasma puff" transit to prevent its immediate escape out the other end of the mirror field.) We were not making plasmas hot enough to cause fusion.

    Back then all workers in the field were ignorant of the many instabilities that existed so we thought mainly in terms of long term confinement fusion reactors. The Dense Plasma Focus, DPF, as a pulsed fusion reactor did not look at all attractive when we thought and hoped a plasma could be contained. The DPF & "inertial confinement" became more interesting as researcher leaned how hard confinement was.

    The DPF has the strong current in contact with electrodes, and so would rapidly quench due to the influx of electrode atoms, but of course that is no problem if it only last a few microseconds as there is the transit delay keeping it clean. We wanted to make a clean plasma to inject into the "confinement" magnetic mirror device. (Confinement is in quotes as magnetic mirrors really just leaks slowly, but as the field strength increases in all directions moving out from the center, the dia-magnetic plasma is happy to quietly sit in the center without any instability growing. (Only those ions that happen to scatter onto the axial field lines escape out the ends of the mirror.)

    --------------
    *The azimuthally pinch is made by fast gas valve "puffing" a slug of gas, weakly ionized, into the vacuum tube and when it arrives on axis of very strong single turn coil, the condenser bank is dumped thru that one turn coil. (It must be physically strong or it will explode.) This induces an azimuthal eddy current in the plasma (in contrast to the DPF's longitudinal current) that also pinches and radial compresses as it tries to move away from the external single turn coil’s driving current. As this induced current never contacts any electrode this plasma remains clean. - It is even moving radially inward so does not even contact the vacuum tube walls.

    I wanted not only this clean plasma but also to accelerate the plasma along the simple axial solenoid field. Thus my "single turn" was with taper and we called it a "conical pinch." It did rapidly eject collapsing plasma "puff" out the larger diameter end of the conical turn with great speed** down the axis of the uniform solenoid field, which surrounded the meter long glass vacuum tube.

    As I have worked with both pinch geometries, I don't need to read about them, except perhaps to better understand why they cannot (yet?) make break even fusion.

    ** A huge force applied to a very tiny mass tends to do that.

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    I never tried to calculate the specific impulse of that fast slug of plasma, but probably should have. It might be quite large. Perhaps for deep space mission this is the way to go, getting the electric power to charge the condenser bank from a compact fission reactor, like used on US submarines. Who knows? - My simple 50 year old technology may be the best.

    Later, after doing a little search on "conical plasma guns" I discovered that they are now called Theta or Z pinch guns and that my friend and co-worker at APL, Bob Turner, added a second single turn about a decade later than my gun had. He gives enough data (in strange form) I think to calculate the specific impulse here: http://pof.aip.org/resource/1/pfldas/v13/i9/p2398_s1?isAuthorized=no

    Bob had just gotten a divorce and at lunch one day said something funny I will never forget: "There are some real bargains out there in the used lady market." I later discovered he was correct.
     
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  15. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    Whatever happened to making progress? It's like we got stuck 50 years ago. We can do a whole lot of sweet stuff now, like plasma tvs (different kind of plasma, I'm sure), but we haven't made much progress on energy or propulsion....

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  16. ElectricFetus Sanity going, going, gone Valued Senior Member

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    GIYD GIYD! GIYD!!!

    Did not say they were recent, have and old Life national library book that describes it and it was written before the moon landings! Merely implying it was under researcher. We are putting 50 billion into ITR, which we know will be an economic failure, even if it does work it won't be economical, and yet we can't even get a few million for DPF and Bussard's Polywell, designs which if they did work (if!) would be highly economical and world changing.

    Only a small percentage of the plasma that does not enters the pinch vortex touches the electrode. No x-ray cooling is their biggest problem, they claim through extreme magnetic fields and angular momentum they somehow defeat this problem, sound like overly optimistic bunk, if you could do a good read and get back to me on it.
     
  17. dhcracker Registered Senior Member

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    I think we have but we don't know about it. I have family that work at wright afb, and I have been told more or less that we have stuff that fly fast enough to enter orbit, that "ufos" do not come from other planets. We have stuff that defies the accepted understanding of physics. The program is so secret that disinformation extends into EVERY aspect of our lives, from whats on TV to what we learn in school.

    I think until the entire world is under the influence of "western society" we will never know what they have. Apparently its a very dangerous technology. It makes sense though because if its really that dangerous and if its easy to pull off then you don't want insane dictators to have the power to destroy society.

    Anyway thats my theory on why we are stuck and seem to be at the limit of what we can do.
     
  18. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

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    It is a clever idea but even it they can keep the plasma off the internal rods, those rods will be subject to initially neutral particle liberating radiation flux to quench the plasma well below fusion temperatures.

    I.e. The impurity atoms become ions in the plasma, only partially ionized, are constantly being excited and then radiate the energy* they absorbed up to a million times each second (How much gets complicated as depends up states and their transition probabilities). 10 million ev radiated away per second by only a few inpurity atoms is more than the total energy in the plasma (as the fusion atom density is so low.

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    *If highly ionized that energy will be X-rays. Perhaps that is the reason the DFP is a strong X-ray source? - I have not read much about it and lack interest enough to do so now. If you know why it makes X-rays, tell.
     
    Last edited by a moderator: Oct 15, 2010
  19. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    15,162
    That sounds like a good hypothesis, but there has been a lot of talk about UFOs disarming nuclear bombs. Not sure if that would fit....
     
  20. TruthSeeker Fancy Virtual Reality Monkey Valued Senior Member

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    15,162
    I'm sure they take much more into account. Certainly the size and power of the star.
     
  21. ElectricFetus Sanity going, going, gone Valued Senior Member

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    It calculated based on the light intensity per distance from the star.
    It is the region were liquid water is possible based on vacuum temperature. Of course different unknown atmospheric consideration could still make it a hell like venus or a frozen desert like mars but considering Gliese581g (orbiting between "c" and "d") is a large planet it atmosphere and it green house effect is likely to be greater than little old earth's.

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    but all this might be moot for now as Gliese581g might not exist at all!
    http://www.sciencenews.org/view/generic/id/64308/title/Existence_of_habitable_exoplanet_questioned
     
    Last edited: Oct 16, 2010
  22. ElectricFetus Sanity going, going, gone Valued Senior Member

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    18,140
    To Billy T

    Off-topic discussion over, don't want to hear it.
     
  23. dhcracker Registered Senior Member

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    Sure it does don't you think that we have an interest in being able to disarm nuclear facilities? I think if that happened it was a simple EMP, or maybe it hints to the magnetic properties of the craft itself. If you were CIA wanting to test it out you would use your own facilities and you wouldn't tell the people working there to see if they could respond as if it was a real threat.

    Anyway I've been researching that hypothesis for about 4 years now, I'm writing a sci fi book about it atm. I've interview lots of scientists about it and managed to get lots and lots of information, but still nobody has much any clue what the propulsion device could be. It has to be oustide our current scope of understanding.

    At one time I thought it may be some kind of gravitational wave device, but again under our current understanding of materials and gravity its impossible to build a GW machine. Some people think there may be a far more complex relation between magnetic fields and gravity wells that may make such a device possible, but there is notthing you can come up with in math to back it up.

    I had an interesting conversation with Stirling Colgate about that specific aspect of dynamos and surprisingly he was very very up to date on the hypothesis. He told me something that made me wonder, he told me that there are aspects of dynamo research that are black projects and he can't talk about. He seemed very willing to help me with the book. No doubt he is of the same mind that ufos are ours not from aliens.. makes you wonder doesn't it.

    Stirling Colgate works at los alamos, he builds mostly dynamo experiments but he has worked on the H bomb and lots of black projects. Right now he is building a dynamo that explores black hole excretion discs, pretty cool stuff.
     

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