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What can you tell me about wakefield plasma acceleration?

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  1. Dec 21, 2013 #1
    I'm trying to read as much as I can about the topic. So I've read over wikipedia and watched some videos and such.

    It seems to me, this method of plasma acceleration would be prime for space thruster applications. Right now VASIMR is using ICH rf coupling to accelerate their plasma. They should ditch that entirely and move to wakefield plasma acceleration if it's at all possible within in the context of their current design.

    I'm not sure about the math behind this, but I'm under the assumption that the closer we get to relative speeds with ion ejection, the higher the efficiencies are going to be for Electricity to Force conversions (assuming the coupling efficiency remains the same). So let's stop wasting our time with 0.01% c plasma excitation, and really focus on getting to 50% - 99% c.

    Whatever the electricity cost, I could really careless about, because if we can develop an engine strong enough for terrestrial liftoff, there will be limitless potential for where we can go with it and you'll really see progress ramp up!
     
    Last edited: Dec 21, 2013
  2. jcsd
  3. Dec 21, 2013 #2

    ZapperZ

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    You have a severe misunderstanding about this principle.

    The plasma wakefield acceleration so far is used to generate high gradient fields to accelerate charged particles, currently just electrons. Why you would want to use this for space thruster is very puzzling.

    First of all, the wall-plug efficiency is extremely low (we're talking about less than 5% here). Secondly, so far, the technology can only accelerated very small electron bunches (significantly less than 1 nC per bunch), which isn't very much (but enough for many high energy physics applications). Try and figure out how much of a push you think you can get out of that many electrons.

    Zz.
     
  4. Dec 21, 2013 #3
    Ok, that's a smidgen of the type of information I'm looking for. Now if the plasma density were increased would it be possible to increase the wall-plug efficiency? Or alternatively, have an experiments been scaled upwards?
     
  5. Dec 24, 2013 #4

    ZapperZ

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    No, you'll just make it worse, because now you need to put in even MORE energy to create that plasma. Furthermore, the quality of the electron beam you will get will be worse, because the non-linear effects will be even larger.

    Zz.
     
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