Recombination of plasma ions and electrons

[asdf1]

If plasma is a collection of positive ions and electrons, why don't they recombine together and become neutral?

 

[malawi_glenn]

too high temperature I guess, and pressure.

ans was this a homework question?

http://en.wikipedia.org/wiki/Plasma_recombination

 

[Astronuc]

If plasma is a collection of positive ions and electrons, why don't they recombine together and become neutral?

they will until the atom gets hit by a high energy particle and ionizes it again.

Recombination is a source of loss of energy from some plasmas.

Also, as malawi_glenn indicated, if the electron and ion temperatures are high, the electron will not recombine with the atom.

Consider that fusion plasmas have energies on the order of keV, and compare this with the ionization temperature of 13.6 eV for H, or 24.6 eV for 1st ionization energy of He.

http://facultyfp.salisbury.edu/dfrieck/htdocs/212/rev/table/ie.htm

The ions and electrons remain somewhat 'spatially' neutral, in that net postive or negative areas do not readily form.

Electrons also interaction the ions through brehmsstrahlung interaction, which is also a source of energy loss from plasmas, as well as cyclotron radiation.