Physics A-Level
Control rods
What Control rods means in Physics A-Level, as defined for AQA, OCR.
Definitions of Control rods
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Reference: AQA
Components that absorb neutrons strongly to regulate the rate of fission, needing a high neutron absorption cross-section and the ability to be inserted and withdrawn safely.
Made from boron or cadmium, these absorb neutrons; inserting them deeper reduces the neutron flux and lowers the reaction rate, while withdrawing them raises it.
Made of a neutron-absorbing material such as boron or cadmium, these are inserted or withdrawn to absorb neutrons and so regulate the rate of the chain reaction.
Topics that use Control rods
- Induced fission (A-level only) (AQA A-Level)
- Nuclear fission and fusion (OCR A-Level)
Related terms
- Chain reactions
- Moderator
- Alpha and beta decay
- Balance of neutron production and absorption
- Barium
- Binding energy
- Binding energy per nucleon against nucleon number curve
- Characteristic X-rays from shell transitions
Using Control rods in the exam
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