lecture 7 light sources, filters, and monochromators harris ch.20
Post on 21-Dec-2015
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TRANSCRIPT
Lecture 7
Light sources, filters, and
monochromators
Harris Ch.20
Light Source
Sample
Monochromator(filter,
wavelength selector)
Detector
SpectrometerData Processing
Black body radiation
A tungsten lamp
3000 K
Deuterium Lamp
hHHHEH '''202
Deuterium: higher intensity
Even higher intensity: Xe arc
UV sources
Light Source
Sample
Monochromator(filter,
wavelength selector)
Detector
SpectrometerData Processing
Filters
nl 2maxthickness
Refractive index
A Bunsen monochromator
Detector plate
Refractive index of NaCl350 nm 1.58460 nm 1.56 680 nm 1.54 1250 nm 1.53
7.30m 1.51 10.6m 1.49 12.0m 1.48 13.1m 1.47 14.2m 1.46 15.1m 1.45 16.0m 1.44
Quarz prisms
LittrowCornu
Czerney-Turner monochromator
)sin(sin dn
nN
Diffraction order
Number of grooves
cosd
n
d
d
Dispersion:Resolution (resolving power):
