1. Joined
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    16 Jul '08 16:32
    Originally posted by sonhouse
    I think that is correct, anti-protons, maybe even anti-electrons, but they would have opposite charges.
    Anti-protons and protons have the same electrical charge, that doesn't change.
    So a negative charged mesh would preferentially attract anti-protons and protons alike, I don't know how you would separate them, I assume the mass would be the same, maybe t ...[text shortened]... harged POSITIVE to attract anti-protons.
    So that positive charge would REPEL protons. Neat.
    "Anti-protons and protons have the same electrical charge, that doesn't change." No, not correct. I found this at www.britannica.com/EBchecked/topic/28507/antiproton

    "antiproton - subatomic particle of the same mass as a proton but having a negative electric charge and oppositely directed magnetic moment. It is the proton’s antiparticle."

    Negative charge, the same charge as an ordinary electron.

    Sonhouse: "So a negative charged mesh would preferentially attract anti-protons and protons alike"

    Again, no. A negative charged mesh would attract positrons *and* ordinary protons.

    Yes, an anti-electron and a positron is the same thing.

    When you say 'harvest antimatter with a charged mesh', I associate with another thing. Also about interstellar travel:

    When going in high velocity in interstellar space it is possible to harvest the sparse amount of hydrogen in space by (1) ionisize the matter in front of the spacecraft (2) collect the ionisized hydrogene with a mesh (à la sonhouse) and (3) use it as a fuel. Studies has shown that it is possible. (?) But this has nothing to do with antimatter.
  2. Subscribersonhouse
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    17 Jul '08 01:20
    Originally posted by FabianFnas
    "Anti-protons and protons have the same electrical charge, that doesn't change." No, not correct. I found this at www.britannica.com/EBchecked/topic/28507/antiproton

    "antiproton - subatomic particle of the same mass as a proton but having a negative electric charge and oppositely directed magnetic moment. It is the proton’s antiparticle."

    Negative c ...[text shortened]... Studies has shown that it is possible. (?) But this has nothing to do with antimatter.
    I updated my post maybe before you read the update, I found the same things, anti and regular matter have opposite charges, which is why electric fields can separate the two types.
    The hydrogen ram scoop has been theorized for decades and it even appears that fusion rockets may be developed. Apparently fusion in a long rocket assembly (maybe miles long, not sure) can allow fusion to develop in beam accelerators, which won't work on earth because it would be too expensive but in a rocket, no other method besides AM will give us the solar system for real. I think there was an article in Analog Science Fiction magazine about that. Analog has very good science articles along with the sci fi fare. The was also a very provocative article a few years ago about future lunar cities and how to get the energy for moon flights by sending material from the moon accelerated in magnetic slings powered by solar energy where the material gains gravitational kinetic energy by the fact that going from the moon's low gravity field to the earth will impart kinetic energy to the material at an energy equivalent of 6 times the energy in gasoline! It would be caught by the reverse of the magnetic sled but in orbit around the earth which would slow down the incoming stuff and convert it electromechanically to electricity stored in some fashion, superconductive coils, magnetic rotors, batteries, whatever. Then use that energy to launch ships to the moon or beyond on the same sled used for incoming material. Pretty slick but it is only useful if there are in place large populations already in place on the moon, still it's a slick concept.
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    17 Jul '08 14:50
    OK, to collect and store antimatter from space you don't want to use electric fields as they would atract particles to the field generator which if the particles are antimatter they will simply annihilate on impact and you'd never collect anything. so you use magnetic fields which can direct moving charged particles into magnetic bottles where they can be stored.
  4. Subscribersonhouse
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    17 Jul '08 18:14
    Originally posted by googlefudge
    OK, to collect and store antimatter from space you don't want to use electric fields as they would atract particles to the field generator which if the particles are antimatter they will simply annihilate on impact and you'd never collect anything. so you use magnetic fields which can direct moving charged particles into magnetic bottles where they can be stored.
    If you have a positive charge on a mesh, it will exclude protons but attract anti protons. It will also attract electrons so you would have to keep those at bay, and like you say, magnetic fields would have to be used in conjunction with electrics. In my previous field, ion implanters, we did exactly that, accelerate ions with electric fields but used powerful magnets to separate the ions by mass, by having a field perpendicular to the ion beam path and the mag field causes the ions to take a right turn, the desired isotope going exactly 90 degrees and the rest either more than or less than 90 degrees depending on the mass of the ions.
    I can see the incoming particles being funneled in and taking a turn in a controlled mag field ala ion implanters, also used in mass analysis machines. Once the desired mass and charge is trapped, it would be sent in a continuous loop not touching any regular matter.
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    17 Jul '08 19:31
    I don't really believe in the anti-matter harvesting thing.
    The yield will be too small with too expensive methods.
    But perhaps I might be wrong. Let the future show.
  6. Standard memberAThousandYoung
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    17 Jul '08 20:18
    Originally posted by FabianFnas
    I don't really believe in the anti-matter harvesting thing.
    The yield will be too small with too expensive methods.
    But perhaps I might be wrong. Let the future show.
    This spacecraft sounds like a baleen whale.
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    18 Jul '08 13:48
    Originally posted by FabianFnas
    I don't really believe in the anti-matter harvesting thing.
    The yield will be too small with too expensive methods.
    But perhaps I might be wrong. Let the future show.
    Well I found the source, a Dr Gerald P Jackson, who founded a company called Hbar. I found his email address and emailed him with some questions about the process. Here is one link to just a list of Hbar employees:
    http://www.hbartech.com/about_us.html

    When you look at such a charged mesh, say we are attracting antiprotons:
    Then you use a positively charged mesh. So you get whatever anti-protons are in the vicinity as well as others like electrons and muons (electron like particle with a negative charge but 200X the mass of electrons) and such.
    Now the first thing we see in such a mix is the fact that like charges repel so all the particles would self repel each other and would not naturally collide except for random chance collisions with just the right energy, so the cloud of stuff would not react. The question I posed to Dr Jackson is what technique would you use to separate out anti protons?
    I used to be a field service engineer on ion implanters (google them if you don't know what they are, no space for that here)
    and my company was called Varian and Associates. No longer in the ion implant business, they sold it back to the original owners, Exrtion in Glouscester, Mass.
    Anyway, my working assumption is you would use a part of the implanter called a mass analysis unit, which is a uniform magnetic field perpendicular to the ion beam of interest which causes the beam to turn around the magnetic moments, the exact angle depending on the exact mass of the ion in question. The magnetic field strength is adjustable so that the ion or particle of choice is bent at some exact angle, in implanters, either 60 or 90 degrees, depending on the design, and then the out going beam focused to about the size of a pencil and in my concept injected with permanent magnets into a circular path. That would be the way I would pursue such a project. So that was the gist of my question to the esteemed Dr Jackson. I will report here any correspondence with him.
  8. Standard memberAThousandYoung
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    19 Jul '08 19:38
    Originally posted by sonhouse
    Well I found the source, a Dr Gerald P Jackson, who founded a company called Hbar. I found his email address and emailed him with some questions about the process. Here is one link to just a list of Hbar employees:
    http://www.hbartech.com/about_us.html

    When you look at such a charged mesh, say we are attracting antiprotons:
    Then you use a positively c ...[text shortened]... gist of my question to the esteemed Dr Jackson. I will report here any correspondence with him.
    Forcing charged particles to move in circles requires energy. How much?
  9. Subscribersonhouse
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    20 Jul '08 18:48
    Originally posted by AThousandYoung
    Forcing charged particles to move in circles requires energy. How much?
    I think there is a problem like that, charged particles moving in circles or just changing direction of travel give off radiation so that alone should require more energy to circulate, or maybe the beam of anti's wears down after a while.
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    20 Jul '08 19:07
    Originally posted by AThousandYoung
    Forcing charged particles to move in circles requires energy. How much?
    not much (using superconducting magnets) remember we are talking about VERY light objects here, however this is very much maybe someday this might be technically possible in the future stuff. As demonstrated by the sheer cost and time required to have not quite yet finished a fairly modest space station (years and billions behind schedule and over budget) in low orbit, the technical challenges of building giant AM collector arrays around Jupiter to harvest fairly tiny amounts of Antimatter would be very hard to justify if even possible. Its one of these things that's fun to think about but nowhere near feasible at present.

    one thing to note, is that the idea of collecting AM is that it is a very dense energy source, (a tiny fraction of a gram would more than power one of our probes for the entirety of its mission) and is prized for spacecraft for the shear power to weight and power to volume ratios, this means that it may well be worth expending more energy than released by the antimatter to collect it.

    hear on earth however AM is stored in magnetic bottles at one particle accelerator where it's collected before being used in experiments.
  11. Subscribersonhouse
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    21 Jul '08 01:50
    Originally posted by googlefudge
    not much (using superconducting magnets) remember we are talking about VERY light objects here, however this is very much maybe someday this might be technically possible in the future stuff. As demonstrated by the sheer cost and time required to have not quite yet finished a fairly modest space station (years and billions behind schedule and over budget ...[text shortened]... tic bottles at one particle accelerator where it's collected before being used in experiments.
    The AM harvesters talked about would not have to be out at Jupiter but only half way to the moon, a big difference. The amount of AM stored in accelerators is more like nanograms and not likely to get much stronger ever. That is not a viable AM production technique. The only viable way so far is to harvest it in space. I think the actual cost would be less than the ISS, the main hardware would be the mesh and then the much smaller internal steering and circulation equipment. The actual mass of the mesh would not have to be very high, its main job would be to support the electric field so it could theoretically be carbon nanotubes which are excellent conductors of electricity. By the time an AM harvester becomes viable for real, there will be a lot of development of materials like carbon nanotubes and such. They would also make possible the space elevator, another science fiction for now technique of getting into space. But if the fiber gets to be about 100 times stronger than steel, it will be possible, making access to space that much easier, no more giant flying bombs.
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    21 Jul '08 05:36
    Okay, go for the anti-mater then...

    How do you convert antimatter to energy used for a propellant in spaceships?
  13. Subscribersonhouse
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    21 Jul '08 09:07
    Originally posted by FabianFnas
    Okay, go for the anti-mater then...

    How do you convert antimatter to energy used for a propellant in spaceships?
    Actually the design for that is way further along than the design for fusion rockets. If you whack an anti and a stuff together, they turn into a nice set of gamma rays. So you carefully place the anti stuff and the stuff to meet where it is surrounded by but not touching some propellant, when the fit hits the shan, so to speak, the resultant gamma's heat the propellant, so you carefully, (VERY carefully) count out the exact # of anti stuff atoms and stuff atoms to meet and you make sure you use something that can absorb gamma (not sure what that is actually) and thereby heating WAY up🙂 and thense out the rear end of the rocket with a specific impulse of something like 10 million. Them are a whole lot better than chemistry with its paltry 450 pretty much max (H2+O2)
  14. Joined
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    21 Jul '08 10:23
    Originally posted by FabianFnas
    Okay, go for the anti-mater then...

    How do you convert antimatter to energy used for a propellant in spaceships?
    Shoot a beam of AM into a Bigger beam of matter. Am annihilates some of the matter releasing lots of energy, resultant plasma shot out of back of spaceship.
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    21 Jul '08 10:49
    Originally posted by sonhouse
    The AM harvesters talked about would not have to be out at Jupiter but only half way to the moon, a big difference. The amount of AM stored in accelerators is more like nanograms and not likely to get much stronger ever. That is not a viable AM production technique. The only viable way so far is to harvest it in space. I think the actual cost would be less ...[text shortened]... steel, it will be possible, making access to space that much easier, no more giant flying bombs.
    The AM harvesters talked about would not have to be out at Jupiter but only half way to the moon

    The reason for putting them around Jupiter (specifically in Jupiter's Van Allen belts) is that AM is very scarce, and Jupiter's GIANT magnetic field acts to collect and concentrate the antimatter making it much easier to collect.

    The amount of AM stored in accelerators is more like nanograms and not likely to get much stronger ever. That is not a viable AM production technique. The only viable way so far is to harvest it in space.

    I am aware of this. I was saying that storing AM in magnetic bottles isn't theoretical, it is being done today, at a particle accelerator near you kind of thing.

    I think the actual cost would be less than the ISS, the main hardware would be the mesh and then the much smaller internal steering and circulation equipment. The actual mass of the mesh would not have to be very high, its main job would be to support the electric field so it could theoretically be carbon nanotubes which are excellent conductors of electricity. By the time an AM harvester becomes viable for real, there will be a lot of development of materials like carbon nanotubes and such.

    Calculating the cost of such a platform is extremely difficult, as you are relying on as yet undeveloped technology. It is easy to say that in the future we will have fantastically advanced technology that will make everything easy and cheap, and it might be true, we can but hope, however to get there we have to develop this technology, which is very hard and extremely expensive. Nanotubes are a very promising bit of technology, but they still have weaknesses, and can only be made at present in minuscule amounts, at great expense.

    They would also make possible the space elevator, another science fiction for now technique of getting into space. But if the fiber gets to be about 100 times stronger than steel, it will be possible, making access to space that much easier, no more giant flying bombs.

    Possibly, They are in individually significantly stronger than you state, however there is some significant difficulty making them with no defects (which massively reduce that strength) and coming up with a method of connecting them together in such a way as to retain that strength, they are also prone to being degraded by radiation and chemical attack, which is bad for both a space elevator and an AM collector.

    Also you keep stating that you need/would want an electrically charged surface for collecting AM particles. This would be a bad idea, since an oppositely charged particles would rush towards your collecting surface and impact into it. if the particles are anti matter they will the proceed to instantly annihilate with there regular matter counterpart in your collector. This is why you want magnetic fields, which direct charged particles along field lines and into your collecting magnetic bottle. Think about the Earth's magnetic field which directs charged particles towards the poles, creating the aurora. If you replace earth with your collection station and place a collector at each pole then you have something like what I am talking about.

    It is also debatable as to weather it is practical or worthwhile to do this, weather the AM yield would be worthwhile, it isn't cut and dried.
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