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"Backyard Scientist" - idiocy never fails to astound me
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TimFox:
Radiation intensity from a point source, such as the electron spot on the anode of an X-ray tube, falls off as the distance squared, not cubed.  With a flat anode surface, there is an angular dependence with direction away from perpendicular to the surface.
coppercone2:
in regards  to the xray tomfoolery,

i don't know if you want the whole detector apparatus in a strong x-ray beam. I don't know if it could effect the ADC or other circuits associated with doing counts. Perhaps it can break something there. I think it should be a remote gieger probe on a shielded cable that connects to the ADC outside of the x-ray flux. The machine could possibly become decalibrated and fail to alert the operator of other dangers (like test source leakage).

This applies to everyone doing radiation experiments IMO. For strong sources you should use a remote probe (one without local amplification), and not irradiate a SMD circuit board. That is not equipment you want exposed to anything at all since its potentially life critical.

The way those portable machines work is that they expect you to run when it starts beeping. I doubt you get a super rad hardened circuit for 200$.
jogri:

--- Quote from: Lord of nothing on August 01, 2020, 09:54:52 pm ---@m98 some People picked up some De pleaded Uranium Ammunition who was used in the illegal Yugoslavia War.


--- Quote ---the radiation from a x-ray tube is directed in one direction
--- End quote ---
Well inside the Housing or even when the (idiots from Ukraine) took it apart and use the "naked" Lamp?

--- Quote ---That's not at all the case with a laser beam
--- End quote ---
What we dont know if he was calling the Authorities before he perform his Test.
Sure some Youtuber dont show everything behind the scenes when it get into thinks who are maybe seem not so legal at first. I was talking with the Austrian Military Press Staff its possible to get Access to the huge Military Training Area for Filming. So in the case I would like show what happen back then I would maybe do some "sneak into" think to pretend I would do some illegal stuff but it would be approved by some officials. Maybe behind the Scenes are some poor Recruit over watch me.  :-DD

--- End quote ---

An X-ray tube always has a main beam direction as the target of your electron gun is a Cu/Mo plate sloped at ~45° -> the beam exits the tube at a ~90° angle. And since the sloped anode is inside the tube it doesn't matter that much if it still has a casing (sure, you'll get more radiation in unwanted directions without it but the beam form doesn't change).

And i don't think that authorities would approve pointing a 200W laser at your neighbours house, so i heavily doubt that he informed them about his plans...
TimFox:
The target material in an X-ray tube depends on the operating voltage.  Besides Bremsstrahlung (radiation from stopping the electrons), there are “characteristic X-rays” from inner-shell transitions in the target atoms.  Above maybe 80 kV, the target is usually tungsten, to exploit the 58 and 59 keV characteristics, but mammography is done at much lower voltage, using molybdenum.
jogri:

--- Quote from: TimFox on August 01, 2020, 10:45:42 pm ---The target material in an X-ray tube depends on the operating voltage.  Besides Bremsstrahlung (radiation from stopping the electrons), there are “characteristic X-rays” from inner-shell transitions in the target atoms.  Above maybe 80 kV, the target is usually tungsten, to exploit the 58 and 59 keV characteristics, but mammography is done at much lower voltage, using molybdenum.

--- End quote ---

Bremsstrahlung (german for "breaking/deceleration radiation") doesn't stem from electrons being stopped (that would yield monochromatic radiation at the energy of your tube voltage), it comes from the interaction between accelerated electrons and the positively charged nuclei: The electron experiences an attraction towards the nuclei -> gets decelerated as it flies by -> the kinetic energy lost in the deceleration gets emitted in the form of a x-ray photon. Since this effect (attraction and loss of kinetic energy) depends on the distance between the electron and the nuclei (the electron speed is set by the tube voltage) you get a continuous spectrum.

Afaik you don't really use tungsten because of its K-alpha lines, it's used because it is one of the only materials that can withstand the extremely high voltages (up to 120kV) that produce extreme anode temperatures: Tungsten has a high melting point and doesn't get soft when it's heated, this drastically reduces the deformation of the anode and the sputtering of tungsten (you would just melt your Cu/Mo anodes and sputter them inside your tube).
Higher tube voltages drastically decrease the dose of radiation (higher energy photons have a higher penetration-> the number of photons (and therefore accelerated electrons) needed for an image with the same intensity decreases with increasing tube voltages as more photons reach the detector), so in radiology they are more interested in the 110-120 keV photons from Bremsstrahlung and not so much in the ~60 keV K-alpha photons.
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