Photomultiplier
A photomultiplier is a device that allows us to see really tiny amounts of light that our eyes can't see by themselves. It works kind of like a magnifying glass for light.
First, we have a special material called a photocathode that absorbs any light that hits it. When the light is absorbed, electrons (tiny particles in atoms) are freed from the material and start moving around.
These electrons then move into something called a dynode. This is like a staircase shape made up of lots of tiny parts, and each time an electron hits a part, it creates even more electrons. This happens lots of times, so by the end, we have lots and lots of electrons all moving around.
Finally, all these electrons end up hitting a special little wire, which records how many electrons hit it. This gives us a signal that we can use to figure out how much light there was in the first place.
So, in short, a photomultiplier takes in tiny amounts of light and magnifies it, making it so we can see things that would otherwise be too dark for us to see.
First, we have a special material called a photocathode that absorbs any light that hits it. When the light is absorbed, electrons (tiny particles in atoms) are freed from the material and start moving around.
These electrons then move into something called a dynode. This is like a staircase shape made up of lots of tiny parts, and each time an electron hits a part, it creates even more electrons. This happens lots of times, so by the end, we have lots and lots of electrons all moving around.
Finally, all these electrons end up hitting a special little wire, which records how many electrons hit it. This gives us a signal that we can use to figure out how much light there was in the first place.
So, in short, a photomultiplier takes in tiny amounts of light and magnifies it, making it so we can see things that would otherwise be too dark for us to see.