how do x-ray machines work?

Question

what really goes on inside the machine?

Answer 1

X-rays are generated when high-energy electrons are fired at a metal plate. These electrons are accelerated across an electrical potential and by the time they collide with the metal surface they are traveling very fast and posses a lot of energy (relatively speaking). When the electron collides with the metal target it is quickly stopped. The energy the electron possessed is converted into electromagnetic radiation (like light). The EM radiation which is produced is of such a high energy that it is classified in the X-ray portion of the EM spectrum.

E = hv
Where E is the energy of the photon of light,
h is Planck's constant (6.63 E-34 J s),
and v is the frequency of the light (X-rays around on the order of E18 Hz).
From this, we can see that X-ray photons have energies on the order of E-16 Joules (~ keV [kilo-electron volts]), or so. By our everyday standards, this is not so much...but when talking about light, this is a huge quantity of energy. Compare the energy of an X-ray photon to that of a visible photon of wavelength ~400 nm ("violet"). The visible photon would have an energy of only about 3 eV, whereas X-ray photons are in the thousands of eV.

Once these X-rays are generated they are directed out of the machine onto a specific target for a brief period of time. X-rays will easily pass through skin and other non-dense medium but have a harder time getting through bone. As a result you can form an image with X-rays by exposing the photographic film to the light shown through the body.

Because of their high energy, X-rays can also be somewhat dangerous. If an X-ray of a high enough energy is absorbed by an electron in your body, the atom the electron is around could become ionized as the electron is 'kicked off' and ejected (due to the photoelectric effect). The resulting ion might react in an undesirable way with other atoms in your body.

Answer 2

Visit
http://www.launc.tased.edu.au/online/sciences/physics/Xrays.html

Answer 3

Hi. Generally they accelerate electrons towards a metal barrier. The sudden stop generates photons in the X-ray part of the spectrum.

Answer 4

Basically, x-rays are a type of energy just like sound or radio. X-rays just have a small wavelength, so they are able to pass through less dense matter such as flesh, yet they can't pass through more dense things such as bone.

They basically just look at the shadow of where no x-rays made it through to determine the bone structure.