Editing Plasma diagnostics (section)

===Photodetachment===

Photodetachment combines Langmuir probe measurements with an incident laser beam. The incident laser beam is optimised, spatially, spectrally, and pulse energy, to detach an electron bound to a negative ion. Langmuir probe measurements are conducted to measure the electron density in two situations, one without the incident laser and one with the incident laser. The increase in the electron density with the incident laser gives the negative ion density.