Extra TopicsTopic Summary
Topic Summary: Background Radiation
Part of Background Radiation — GCSE Physics
This topic summary covers Topic Summary: Background Radiation within Background Radiation for GCSE Physics. Revise Background Radiation in Extra Topics for GCSE Physics with 13 exam-style questions and 12 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 12 of 12 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 12 of 12
Practice
13 questions
Recall
12 flashcards
Topic Summary: Background Radiation
Key Terms
- Background radiation — always-present low-level radiation
- Count rate — decays detected per unit time
- Corrected count rate — measured minus background
- Radon — radioactive gas from uranium in rocks
- Cosmic rays — high-energy particles from stars
- Dose — energy deposited in tissue (sieverts)
UK Background Radiation Sources
- Radon gas: ~50% (natural)
- Medical: ~14% (artificial)
- Food and drink: ~12% (natural)
- Cosmic rays: ~10% (natural)
- Ground/buildings gamma: ~10% (natural)
- Nuclear industry: less than 1% (artificial)
Correcting for Background
- Remove all sources and measure count rate
- Take multiple readings and average
- Corrected rate = Measured − Background
- Background is random — readings vary naturally
Factors Affecting Dose
- Granite rock areas: higher radon levels
- High altitude: more cosmic rays
- Medical scans: significant additional dose
- UK average: 2.7 mSv per year
- 85% natural, 15% artificial