Reply To: A new way of generating electricity

[Brian H]

jamesr wrote:

Here’s an article that has set me wondering: http://www.sciencenews.org/view/generic/id/50258/title/Star_outweighed_any_known_in_Milky_Way

The relevant quote:

Theory predicts that any star heavier than the equivalent of 140 suns blows up in a very special way. Photons produced at the core of such a star provide an outward pressure that resists gravity’s inward pull. But when the core temperature exceeds about a billion kelvins, the photons suddenly become energetic enough to annihilate each other and produce pairs of electrons and positrons.

Is such pair instability a possibility in the FF plasmoid, since temps would be in that range?

Normally for electron-positron pair production, in Compton scattering, you need a photon with at least 1.02MeV (ie twice their rest mass energy of 0.511MeV). I believe, for two photons to annihilate you need to take into account higher order effects of QED, as normally photons do not interact directly with each other, only with charged particles. But the end result is the same, you need a total of 1.02MeV available to create the pair.

Since we are taking about temperatures of 50-100keV you will not really have any x-ray photons with that kind of energy. There may be the odd one created from the energetic fusion products, but nothing significant I would expect.
So the temp ref in the article is wrong? Interesting.