Bicska Shinji just unboxed a new knife.

So I was quietly sitting in my room making a lightsaber plan, but there was a problem.

Yeah, so with the plasma blade idea getting thrown out of the window, I made another plan, based on Evangelion 01-s progressive knife (illustrated in the picture):

Plasma cutting edge

A small plasma line is created around the edge, which lasts until the weapon passes through the target. This line is kept at bay by a magnetic field.


  • What material should I make the knife out, so the molten parts of the armor doesn't damage it?
  • What are the other possible downfalls of this weapon?
  • 1
    $\begingroup$ what they don't show is his hand bursting into flames as soon as he turns it on. $\endgroup$ – John Mar 16 '17 at 19:06
  • $\begingroup$ @John Really? $\endgroup$ – Mephistopheles Mar 16 '17 at 19:35
  • 3
    $\begingroup$ I am referring to the problem of having superheated anything that close to exposed flesh. Radiant heat is still a thing. $\endgroup$ – John Mar 16 '17 at 19:58
  • $\begingroup$ @John Don't worry about that, it's created just moments before the knife reaches a solid object. $\endgroup$ – Mephistopheles Mar 16 '17 at 20:05

Well, plasma cutters work on the concept of jets of gas. Perhaps a similar thing could be used for a 'plasma knife' - an extremely thin, but long, jet of gas that creates the 'plasma' line along the edge. Plasma cutters are roughly around 30,000F (16,649 C). How does this not melt the metal of the cutter? Well, there's a shielding gas. Basically a barrier of gas between the plasma and the solid metal that acts as a buffer, and protects the metal.

For pure flavor, though, there's lots of very high temperature resisting metals: http://www.samaterials.com/content/88-high-temperature-resistance-materials Tungsten is one of my favorites in this category.

  • $\begingroup$ If you got access to a lab capable of working with tungsten, that metal is incredibly fun to play with. I suggest that anyone interested in sci-fi take a look at its amazing properties for some fuel for tought! $\endgroup$ – T. Sar Oct 27 '17 at 10:45

To generate a plasma you need to have two electrodes, a radiofrequency generator setting up an AC potential between them and a suitable gas pressure, so that the gas molecules can be stripped by their electrons and generate the plasma.

If you want the electrodes to be one on each side of the blade, they have to be made of a good conductive material (copper, aluminium, gold...).

Plus you want to control the plasma via a magnetic field, then you are requesting for a ferromagnetic material.

You should then aim to some thungsten coated (to resist molted material) metallic alloy, which has good conductivity, ferromagnetic behavior.


I don't know a lot about this kind of stuff, but you would certainly have to make it out of some type of heat resistant steel. And the possible downfall would be having it turn on in your pocket! :)

  • $\begingroup$ Yeah, that would yield catastrophic results and I would have to buy a new pant. $\endgroup$ – Mephistopheles Mar 16 '17 at 18:41

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