2)Gas Discharge Lamps – two electrodes with
a current between them in a gas filled tube. Excitation results from electrons moving
through gas. Electrons collide with
gas ŕ
excitation ŕ
emission
•At high pressure ŕ “smearing” of energy levels
ŕ spectrum
approaches continuum
•The higher the pressure, the greater the probability
that any given molecule or atom will be perturbed by its neighbor
at the moment of emission.