More specifically, the (low power) x-rays that are created when the electrons hit the screen and slow down are ionizing. The tube used in an x-ray machine is technically just a simple CRT without the mask, deflection coil, phosphorus and shielding, with the acceleration voltage cranked up a lot higher.
With your normal CRT the voltage isn’t high enough to be properly really though, and lack penetration power, so you can shield the tube quite easily. Which is also why it’s not actually harmful for you to sit in front of e.g. a CRT monitor.
Which is also exactly what the CRT itself is – not all of the electrons pass through the mask. The difference is, that the actual CRT part has a longer field to accelerate the electrons, meaning the hit the mask or cathode with a higher energy leading to higher power x-ray photons. Modern tubes just had shielding so it wasn’t a concern, the older ones didn’t.
Technically x-rays are always generated when a particle accelerates. That’s why you can get them even from a high power cyclotron where the particle has a constant force applied on it. The actual CRT creates higher energy electrons and thus will generate more x-rays than the rectifier, it’s calculated simply from the voltage and the overall distance of acceleration. But if the TV had a tube rectifier it’s true that that would generate low power x-rays as well.
radioactive??
electron beams are ionising radiation, yes
More specifically, the (low power) x-rays that are created when the electrons hit the screen and slow down are ionizing. The tube used in an x-ray machine is technically just a simple CRT without the mask, deflection coil, phosphorus and shielding, with the acceleration voltage cranked up a lot higher.
With your normal CRT the voltage isn’t high enough to be properly really though, and lack penetration power, so you can shield the tube quite easily. Which is also why it’s not actually harmful for you to sit in front of e.g. a CRT monitor.
Incorrect. The X-rays from old TVs came from the HV rectifier, in the back of the set.
how exactly does a rectifier produce x-rays?
By being a vacuum tube with a metal target, much like an X-ray tube.
Which is also exactly what the CRT itself is – not all of the electrons pass through the mask. The difference is, that the actual CRT part has a longer field to accelerate the electrons, meaning the hit the mask or cathode with a higher energy leading to higher power x-ray photons. Modern tubes just had shielding so it wasn’t a concern, the older ones didn’t.
Technically x-rays are always generated when a particle accelerates. That’s why you can get them even from a high power cyclotron where the particle has a constant force applied on it. The actual CRT creates higher energy electrons and thus will generate more x-rays than the rectifier, it’s calculated simply from the voltage and the overall distance of acceleration. But if the TV had a tube rectifier it’s true that that would generate low power x-rays as well.
Technically, every forward-biased rectifier emits EM of wavelength and intensity depending on materials.
1N4007 silicon rectifier emits a few THz photons when forward biased.
Use different materials and you have a LED, an inefficient rectifier but great light source.
Tube rectifier with high enough voltage
https://tubedata.jp/sheets/135/1/1DG3A.pdf
They are in the tube. Unless you are in the tube as well, I fail to see the problem. Do you also consider static electricity discharges radioactive?
the lead shielding can’t block all of it, or the tube would not display anything. some x-rays go through.
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