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Old 09-05-2017, 02:09 PM   #51
AlexanderHowl
 
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

You would need a much more powerful magnet than 10 Teslas to even trap a gram of antimatter. Just using a back of the envelope calculation, you would need a 1 million Telsa magnetic field to contain a gram of antimatter for a prolonged period of time (the attraction between antimatter and matter is probably one of the most powerful forces in the Universe). Anything less is just as much handwavium as force fields and other forms of superscience.

If you want hard science rockets, helium-3 fusion rockets are probably much more realistic and much more affordable (helium-3 is created in 50% of DD fusion reactions, so we will have more than enough helium-3 for propulsion purposes in a decade or two). Helium-3 fusion creates 207 GJ per gram (around 0.002% of that of an equivalent mass of antimatter-matter), which means that 1 kg of helium-3 contains as much energy as 1 gram of antimatter combining with 1 gram of matter. Helium-3 is much easier to store, its products are much easier to direct using a magnetic rocket nozzle, and it can be used for a number of other uses than propulsion.
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Old 09-05-2017, 02:41 PM   #52
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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Originally Posted by AlexanderHowl View Post
(the attraction between antimatter and matter is probably one of the most powerful forces in the Universe).
Gravity is one of the weaker forces in the universe and is the only attraction between neutral matter and antimatter.
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Old 09-05-2017, 03:11 PM   #53
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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You would need a much more powerful magnet than 10 Teslas to even trap a gram of antimatter. Just using a back of the envelope calculation, you would need a 1 million Telsa magnetic field to contain a gram of antimatter for a prolonged period of time (the attraction between antimatter and matter is probably one of the most powerful forces in the Universe).
Antiprotons are attracted to protons, positrons are attacked to electrons, but neutral antimatter is not significantly attracted to neutral matter.

Any significant amount of pure charged particles requires ridiculous energy to hold together; if you could hold a gram of antiprotons in one place there'd be no point because you could just hold a gram of protons and get about the same energy storage (1g of protons is about 96,000 Coulombs).
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Old 09-05-2017, 03:19 PM   #54
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

Significantly, magnetic levitation of neutral antimatter is no different than magnetic levitation of neutral electronic matter. It is no more difficult to levitate a gram of antiwater than to levitate a gram of water.
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Old 09-05-2017, 03:20 PM   #55
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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Significantly, magnetic levitation of neutral antimatter is no different than magnetic levitation of normal matter. It is no more difficult to levitate a gram of antiwater than to levitate a gram of water.
Other than rogue gas atoms escaping and colliding with the walls of the containment chamber (or rogue atoms getting into the containment chamber, colliding with the antimatter, and heating it up).
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Old 09-05-2017, 03:23 PM   #56
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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Other than rogue gas atoms escaping and colliding with the walls of the containment chamber.
Well yes, containing antimatter in an electronic matter vessel is more difficult than containing electronic matter in that vessel, which is why you need fields here in the first place! The actual physics of levitation isn't any different though. Neither gravity nor electromagnetism work differently on antimatter, so the attraction between neutral matter and antimatter is just gravity, and the electromagnetic force is stronger.

Which might mean solid storage is better, but as you say it is trivial to freeze stuff.

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Old 09-05-2017, 04:09 PM   #57
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

I wouldn't say trivial, but certainly straight forward and not something beyond TL8.
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Old 09-05-2017, 04:48 PM   #58
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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I wouldn't say trivial, but certainly straight forward and not something beyond TL8.
Freezing water and hydrogen (and really most things) is TL6. Freezing lithium is TL 0.
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Old 09-05-2017, 04:58 PM   #59
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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Freezing water and hydrogen (and really most things) is TL6. Freezing lithium is TL 0.
Well, assuming you have lithium to freeze. Isolating lithium is TL 5.
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Old 09-05-2017, 07:26 PM   #60
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Default Re: [Spaceships] Anti-Lithium for Drives Does this work?

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Freezing water and hydrogen (and really most things) is TL6. Freezing lithium is TL 0.
I thought the reason why superconductors that work at liquid nitrogen temperatures were so sought after was mostly about the high cost of using liquid hydrogen.
And we are talking about major industrial and compact efficient drives, not just technically possible.
That way leads to a breakdown of TL definitions.
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