August 1, 2024
Uranyl Fluorescence Spectra
The idea here is to use spectroscopy to identify fluorescent mineral species via
the spectrum of the light they emit when excited by UV light.
Paul Adams and Storm Sears are busy working on this in August of 2024.
Paul began some work several years ago using a point and shoot camera in
conjunction with a diffraction grating.
Recently these two identified an affordable precision spectrometer and are
pushing forward on this project.
Visible light
From 380 nm to 750 nm
Thunder Optics
Note that "Thunder Optics" would seem to be in France based on the internet domain.
Along with the spectrometer itself, you need a fiber ($50) and lens ($100), so the outlay
to get started with this is $600.
They advertise a 350 to 890 nm range of wavelengths and a 1800-1200 pixel detector
The device is interfaced with a USB 2.0 cable and you get a license for "Spectragryph"
for personal use.
BW Tech Spectrometer
These were originally used in some kind of medical device that did Raman.
You can buy then for $200 on ebay from the seller "spectrophoton".
405 nm laser diode source to generate fluorescence
Edmund" Schott filter to cut 405nm
Calibration sources
Using mercury lines from a fluorescent lamp works well.
Spectragryph software
You have to pay for this if you want to use it beyond the trial period.
However, hold your horses! The author died and the license server no longer
serves -- so If you paid you are up a creek without a paddle.
More details in the following link:
Illumination
Controlling the intensity of the UV illumination is important (critical) otherwise the detector
in the spectrometer can be saturated.
Feedback? Questions?
Drop me a line!
Tom's Mineralogy Info / tom@mmto.org