4 ms·

Do electrons get weird under high acceleration?

analog31 2y ago
Not particularly weird, but they radiate energy as they accelerate. You don't want to be in the same room as this thing when it's running.
- swayvil 2y ago
  What kind of energy?
  - mgc_mgc 2y ago
    Photons. https://en.wikipedia.org/wiki/Bremsstrahlung https://en.wikipedia.org/wiki/Bremsstrahlung
    - analog31 2y ago
      Indeed, and this is a reason why, traditionally, electrons are studied using linear accelerators, rather than rings. It was the main purpose of Stanford Linear Accelerator (SLAC) as I understand it. When electrons are accelerated in rings, it's usually because you want to do something with the radiation, and not the electrons.
    - Loughla 2y ago
      What would that do to you? Sunburn?
      - deleted 2y ago
        [deleted]
      - swayvil 2y ago
        I'm figuring the photonic stuff covers all electromagnetic. So sunburn, microwave, cancer. Lots of options.
      - klodolph 2y ago
        Ordinary consumer equipment already accelerates electrons enough to produce X-rays. Or at least, it did, back in the CRT era. This accelerator is presumably more powerful than consumer entertainment hardware.
- guepe 2y ago
  That reminds me of a question I was asking myself: instead of using rare gas for ion thrusters… why not ejecting very high velocity electrons ? Their mass is much, much smaller than any atom, but why wouldn’t that lead to a thrust ? Possibly without limit except power - no limit on a “tank”?
  - hansvm 2y ago
    Where do the extra electrons come from?
  - sbdhzjd 2y ago
    The thruster would quickly die out once the static electricity on the vessel created an energy well that matches the energy of the electrons thrust. Instead use a powerful laser. Light carries momentum without the need to preserve charge.
    - guepe 2y ago
      Ah! That “well” is exactly what I couldn’t understand from ion thrusters, where they shed electrons as they expulsé ionized gas. All I could find was “to keep the same charge”, but since there is no absolute ground, what’s the problem? You just explained it :)
      - sbdhzjd 2y ago
        Np. I remember first coming to that realization. Fun thought experiment: what happens to a beta emitter in outer space?
  - addaon 2y ago
    > why not ejecting very high velocity electrons ? This works, initially. Now, you have to balance the charge on your space craft, or else you won’t be able to eject any more electrons. If you balance this charge by ejecting protons, you have a hydrogen thruster. If you balance this charge by ejecting positrons, you have a photon thruster (in the far field). The former is still “tank” limited. The latter requires high energy to get any useful impulse.

Not particularly weird, but they radiate energy as they accelerate. You don't want to be in the same room as this thing when it's running.

swayvil 2y ago
What kind of energy?
- mgc_mgc 2y ago
  Photons. https://en.wikipedia.org/wiki/Bremsstrahlung https://en.wikipedia.org/wiki/Bremsstrahlung
  - analog31 2y ago
    Indeed, and this is a reason why, traditionally, electrons are studied using linear accelerators, rather than rings. It was the main purpose of Stanford Linear Accelerator (SLAC) as I understand it. When electrons are accelerated in rings, it's usually because you want to do something with the radiation, and not the electrons.
  - Loughla 2y ago
    What would that do to you? Sunburn?
    - deleted 2y ago
      [deleted]
    - swayvil 2y ago
      I'm figuring the photonic stuff covers all electromagnetic. So sunburn, microwave, cancer. Lots of options.
    - klodolph 2y ago
      Ordinary consumer equipment already accelerates electrons enough to produce X-rays. Or at least, it did, back in the CRT era. This accelerator is presumably more powerful than consumer entertainment hardware.
guepe 2y ago
That reminds me of a question I was asking myself: instead of using rare gas for ion thrusters… why not ejecting very high velocity electrons ? Their mass is much, much smaller than any atom, but why wouldn’t that lead to a thrust ? Possibly without limit except power - no limit on a “tank”?
- hansvm 2y ago
  Where do the extra electrons come from?
- sbdhzjd 2y ago
  The thruster would quickly die out once the static electricity on the vessel created an energy well that matches the energy of the electrons thrust. Instead use a powerful laser. Light carries momentum without the need to preserve charge.
  - guepe 2y ago
    Ah! That “well” is exactly what I couldn’t understand from ion thrusters, where they shed electrons as they expulsé ionized gas. All I could find was “to keep the same charge”, but since there is no absolute ground, what’s the problem? You just explained it :)
    - sbdhzjd 2y ago
      Np. I remember first coming to that realization. Fun thought experiment: what happens to a beta emitter in outer space?
- addaon 2y ago
  > why not ejecting very high velocity electrons ? This works, initially. Now, you have to balance the charge on your space craft, or else you won’t be able to eject any more electrons. If you balance this charge by ejecting protons, you have a hydrogen thruster. If you balance this charge by ejecting positrons, you have a photon thruster (in the far field). The former is still “tank” limited. The latter requires high energy to get any useful impulse.