Sodium Fluorescence Tube on furnace wall

A highly evacuated glass tube containing multiply distilled sodium, for demonstrating the resonance fluorescence of sodium vapour.

Filled with argon, the Sodium Fluorescence Tube is heated in the furnace, between 180 and 200°C, in order to achieve sufficient pressure of sodium vapour. When it is brought to the heated state and illuminated with sodium spectral light, the entire tube emits yellow light at the wavelength of the sodium D line. The sharply defined sodium D line appears in the spectrum.

If it is instead illuminated with white incandescent filament light, the transmitted light exhibits a dark absorption line at the position of the sodium D line. Absorption can be demonstrated even without the use of a spectrometer due to the clear shadow formed when yellow sodium light passes through the tube. 

Experiment topics

The Sodium Fluorescence Tube on Furnace Wall is suitable for demonstrating the following:

• Sodium resonance fluorescence
• Absorption of Na spectral lines in a sodium mist

Additionally required

In order to conduct this experiment, you will require:

• A Heating Chamber

The following are also recommended:

• Sodium Vapour Spectrum Lamp
• Choke for Spectrum Lamps (230V, 50/60Hz)

or

• Choke for Spectrum Lamps (115V, 50/60Hz)
• Optical Lamp, Halogen
• Transformer 12V, 60VA (230V, 50/60Hz)

or

• Transformer 12V, 60VA (115V, 50/60Hz)
• Tripod Stand, 150mm
• Convex lens on stem, 50mm
• Barrel Foot Stand, 0.9kg
• Hand Held Spectroscope with Amici Prism

technical specification

• Dimensions (tube): 170 x 42mm
• Dimensions (hotplate): approx. 230 x 160mm²
• Weight: approx. 550g