Cathode Ray Tube TV Front Glass Spectrum

[Go-Figure]

Hello there,
This is one of the first spectra I took with my kit.
I had noticed before that the front glass of the cathode ray tube TV was the "hottest" object I had at home according to my geiger counter: 400-500 CPM in some spots, 7-8 times the background.
So I knew there was something lurking there and indeed there was.
The spectrum shows the expected peaks for Uranium 238 series, Thorium 232 series and Potassium 40. The Tl208 peak at 2.6 MeV is there as well although not visible in the picture.
In the lower half of the image there's the room background.

While I was taking this spectrum I researched online and found a paper on the subject which I attach in case anyone is interested.

Massimo