Spurious xray emission from triboelectric effect.
Phase change of various materials changing absorption characteristics.
Capacitor discharge.
- Put a crystal of something on a turntable and see if you can capture a video of its scattering angles. Bonus: read the movie and turn it into a 3D model for viewing.
Did you ever XRF that windup toy to see what it was contaminated with? I'll throw in my lot with one of the commenters and guess "Lead."
I had never considered an application of use outside of medicine.
So, my day is now accounted for. In addition to "overdue training" on things I already know, I will be youtubing all the x-ray, MRI, ultrasound fun things that you would never see otherwise.
Thank you OP!
It's also neat how he describes how the acquisition works: 32bit tiffs, pci card, real-time linux, and a special rack-mounted server.
echelon•2mo ago
You don't want to subject yourself needlessly to ionizing radiation. A little here and there is probably okay at small doses and for valid reasons, but it all adds up over a lifetime.
He didn't mention how much X-ray radiation this puts out in the first half or so of the video. I worry it's more than a medical photograph as it's continuous high sample rate video, but I'm not an expert. Would be curious to know.
Also curious about the shielding and leaking.
Don't damage your DNA if you don't have to. This is a cool, semi-educational video. I don't think I'd take the same risk though.
zzlk•2mo ago
see: https://en.wikipedia.org/wiki/Linear_no-threshold_model
eig•2mo ago
Funny thing: it’s actually rare to get radiation damage to human hands and feet since there’s not too much growing tissue there!
scythe•2mo ago
On the contrary, I was told stories in school that old IR doctors used to lose the hair on their hands after using the fluoro for years. The fingernails are also radiosensitive.
The main reason that X-rays of the hands and feet are usually very low risk is because the beam intensity (dose) required to penetrate the small amount of tissue is very low. Because the video uses a high-sensitivity detector (photon counter) the dose may be even less than usual. However, it would still be a regulatory violation if you did it in a hospital.
scythe•2mo ago
Typical fluoro skin entrance exposure rate to go through someone's hand is on the order of 1-3 millisieverts per minute. With a more advanced detector (like this one) it may be lower, but increasing the frame rate or resolution will tend to require higher dose rate. The associated risk of skin cancer is quite small. But please be aware that unnecessary X-Ray imaging of living things is against the law in most jurisdictions.
SoftTalker•2mo ago
scythe•2mo ago
NCRP 172 (published 2015) provides a direct comparison of digital to film for some examinations. For upper GI fluoroscopy without oral contrast the DRL for film is 3.9 mSv and for digital is 1.5 mSv. I think this is roughly typical.
rdtsc•2mo ago
> Also curious about the shielding and leaking.
If you'd watch the video the last part explains exactly that. The energy levels involved, how the beam is stopped, how backscatter is checked. He is definitely no dummy who just found an x-ray machine in a dump and just powered it up for clicks and giggles.