Reply To: Bang or no bang

[jamesr]

malaga2022 wrote:
How tri alpha measures plasma temperature?

Ion temperature is found via a spectrometer looking at the doppler broadening of line emission. You also get the flow towards/away from the detector via the blue/red-shift of the line. NB since the deuterium will be fully ionized except at the very cool edge, it is normal to look for the transitions of impurity ions like carbon C6+ -> C5+. The measurement will be the average along the line of sight.

Electron temperature is done via Thomson scattering, whereby a high power laser pulse is fired through the plasma, a few photons are scattered off the electrons back to a another spectrometer camera looking for the doppler broadening of the scattered laser light. Here normally the laser & detector are arranged so you get a profile of temperature across the plasma. http://en.wikipedia.org/wiki/Plasma_diagnostics#Thomson_scattering