This deep dive covers Industrial Uses of Radiation within Uses & Hazards of Radiation for GCSE Physics. Revise Uses & Hazards of Radiation in Atomic Structure for GCSE Physics with 17 exam-style questions and 5 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 4 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🏭 Industrial Uses of Radiation
Smoke detectors use a small amount of americium-241 (an alpha emitter). The alpha particles ionise the air between two electrodes, creating a tiny current. When smoke enters the detector, it absorbs the alpha particles and reduces the current — this triggers the alarm. Alpha is used because it is strongly ionising (good for creating the current) and is blocked by even a small amount of smoke or air. Crucially, alpha cannot escape the detector casing, making the device safe to have in homes.
Paper thickness control uses beta radiation. A beta source on one side and a detector on the other measure how much beta passes through the paper. If the paper is too thick, less beta gets through; if too thin, more gets through. The detector feeds back to rollers that adjust the paper thickness automatically.
Checking welds uses gamma radiation — it penetrates the metal and reveals cracks or flaws on a detector or photographic film placed on the other side. Alpha and beta cannot penetrate thick metal, so only gamma is suitable here.
Practice questions for Uses & Hazards of Radiation
Which type of radiation is used in smoke detectors?
Explain how a smoke detector uses an alpha source to detect smoke.