Definition
A radiological investigation that utilizes wavelike forms of electromagnetic energy carried by particles called photons which exposes photosensitive film to differing° depending on it’s absorption in the tissue through which it passes.
History
Discovered by German physicist Wilhelm Roentgen in 1895. He won the Nobel prize for physics in 1900. The first xray he took was of his wifes hand.
How it works?
The heart of an X-ray machine is an electrode pair — a cathode & an anode — that sits inside a glass vacuum tube. The cathode is a heated filament, like you might find in an older fluorescent lamp. The machine passes current through the filament, heating it up. The heat sputters electrons off of the filament surface. The positively-charged anode, a flat disc made of tungsten, draws the electrons across the tube.
The voltage difference between the cathode & anode is extremely high, so the electrons fly through the tube with a great deal of force. When a speeding electron collides with a tungsten atom, it knocks loose an electron in one of the atom’s lower orbitals. An electron in a higher orbital immediately falls to the lower energy level, releasing its extra energy in the form of a photon. It’s a big drop, so the photon has a high energy level — it is an X-ray photon.
A camera on the other side of the patient records the pattern of X-ray light that passes all the way through the patients body. The X-ray camera uses the same film technology as an ordinary camera, but X-ray light sets off the chemical reaction instead of visible light.