PIRA: 7B10.10


 Lab Equipment  Directions
  1.  Helium spectra tube
  2. Neon spectra tube
  3. 2 Spectra power supplies
  4. HeNe red laser (special one with plexiglass top)
  5. diffraction gratings (1 for each student)
  6. plug strip
  7. cylindrical diffraction screen
  1.  Place spectra tubes into the power supplies. Carefully stack the two power supplies and turn them on.
  2. Turn on the laser and hold the open window of the laser above the power supplies.
  3. Have students look through the gratings at each spectra and compare.
  4. Notice that the individual spectra are combined in the HeNe laser.