Tag Archives: waves and radiation

x-ray radiation⤴

from @ fizzics

X-rays are a form of electromagnetic radiation.  They have a much higher frequency than visible light or ultraviolet.  The diagram below, taken from Wikipedia, shows where x-rays sit in the electromagnetic spectrum. image by Materialscientist Wilhelm Röntgen discovered x-rays and the image below is the first x-ray image ever taken.  It shows Mrs. Röntgen’s hand and wedding ring.  ... Read more

ultraviolet radiation⤴

from @ fizzics

Earlier this week, we looked at the electromagnetic spectrum, including ultraviolet radiation. image courtesy of sonrisaelectrica The section of the electromagnetic spectrum with wavelengths ranging from 10nm to 400nm is called ultraviolet radiation (uv for short).  Sunlight contains uv rays and it’s those uv rays that are responsible for the suntan you get during the summer holidays.  This Australian animation shows how the ultraviolet ... Read more

equivalent dose⤴

from @ fizzics

This week, we’ve looked at calculating radiation doses.  The absorbed dose, measured in Grays, takes into account the mass of the absorbing tissue, while the equivalent dose (in Sieverts) gives an indication of the potential for biological harm.

Equivalent dose is calculated using a weighting factor.  More damaging forms of radiation have a larger weighting factor.

Absorbed dose and equivalent dose are usually expressed in smaller units; uGy, mGy, uSv, mSv.

Here is a poster from the excellent xkcd site that explores examples of the different levels of equivalent dose.

Click on the picture for a larger version.

Notice that the scale changes as you move through the poster from blue to green to red.

The dosimetry topic is very short and comprehensively covered at BBC Bitesize.