Perhaps dissolve an inorganic salt in the HP that has a bright emission
spectrum.
Yellow using table salt. Red using strontium fluoride. Green using ...
Care should be taken such salts do not poison the cat pack or start HP
decomposition.
Of course.
John Dom
_
Gentlefolk,
Suggest a fairly bright monochromatic source if you can find one; index of
refraction variations bend different wavelengths by different angles. The light
should be some distance from the plume and the shadowboard should be as near
as practical. It may help to be able to vary the
