A radiation detector never reads zero, even with no source in sight. A faint, constant patter of clicks comes from the rocks, the air, the food we eat, and the sky. This is background radiation.
Background radiation is the low level of ionising radiation always around us, from natural sources such as radon gas, rocks, cosmic rays and food, and from artificial sources such as medical uses. It is detected with a Geiger-Muller tube, and its count must be subtracted when measuring a source.
Background radiation is the ionising radiation that is present everywhere, from natural and artificial sources, even with no source deliberately nearby.
Natural sources include radon gas, rocks and soil, cosmic rays and food. Artificial sources include medical uses.
See the steady count from background radiation and how a nearby source adds to it.
Four quick checks. Each correct answer earns XP and lights this skill on your star map.
Background radiation is...
Which is a natural source of background radiation?
Background radiation is detected using a...
When measuring the count rate of a source, you should first...
Most background radiation is natural, with a smaller artificial contribution.
Background radiation is present everywhere, so when measuring a source you must subtract the background count rate to get the true reading. For most people the largest natural contributor is radon gas.
Unlocks once the four checks above are done. Worth more XP, written in the style of Paper 2.
Which of these is an artificial source of background radiation?
A detector reads 30 counts per minute with a source present and 6 counts per minute with no source. The count rate due to the source alone is...
Cosmic rays are a source of background radiation that come from...
Background radiation is mapped. Keep the chain going.