Luminescence of minerals by cathode rays
Physikfan, Thu Nov 17 2016, 04:36PM
The images show minerals in a Geissler tube connected to an induction coil.
Camera Lumix FZ20.
Exposure time 1s
Exposure time 1/50 s
Re: Luminescence of minerals by cathode rays
Proud Mary, Mon Nov 21 2016, 09:24PM
So can these colour effects be ordered about by element with a spectrometer?
Re: Luminescence of minerals by cathode rays
Physikfan, Tue Nov 22 2016, 08:26AM
Hi Proud Mary
The best way to analyze the minerals is to use
1. a mass spectrometer for the elements
2. x-ray diffraction for the structure
3. Raman scattering for additional information
Unfortunately I have no direct access to method 2, method 1 would destroy the tube,
also Raman is not easy.
In this case electron excited fluorescence of these minerals generates these nice colors.
I will post a picture of these minerals under daylight as well in the near future under UV light.
If it is possible I will also try to record the visible spectra of the fluorescence of the different minerals using a direct vision prism.
Regards
Physikfan
Re:
Luminescence of minerals by cathode rays
Physikfan, Tue Nov 22 2016, 12:29PM
Hi Proud Mary
The pictures show these minerals in a Geissler tube at daylight and at artificial light respectively.
Camera Lumix FZ20.
Daylight
Connected to the induction coil at artificial light.
Have you seen the "butterfly in a Geissler tube"?
Re: Luminescence of minerals by cathode rays
Proud Mary, Tue Nov 22 2016, 06:56PM
Very interesting. Thanks for showing us that.
Re:
Luminescence of minerals by cathode rays
Physikfan, Thu Nov 24 2016, 01:34PM
Hi Proud Mary
The images show these minerals in the Geissler tube with UV lighting.
Camera Lumix FZ20.
Not all minerals, that exhibit electron excited fluorescence, show also fluorescence under ultraviolet light.
However, due to UV-glass absorption, only relatively long-wave UV rays can hit these minerals.
Re:
Luminescence of minerals by cathode rays
Physikfan, Sat Nov 26 2016, 05:42PM
Hi Proud Mary
The images show minerals in a Geissler tube (rotated by 180 ° against all previous pictures) with artificial light (LED) as well as in the dark.
The exposure time was the same for all shots, manual focus, camera Canon 40D, Telephoto lens with 250 mm focal length.
With LED light with discharge, induction coil step 1.
With LED light with discharge, induction coil step 5.
In the dark with discharge, induction coil step 1.
In the dark with discharge, induction coil step 5.
Hopefully, I will soon be able to obtain spectroscopic images with a transmission grating or a direct vision prism.