AQA A-Level Physics/Alpha, Beta and Gamma radiation

Exam note For this topic, you to learn a lot of qualitative information, meaning that the questions in the exam will not only be testing your knowledge on how to do various calculations, but they will also ask you to explain and describe the underlying processes, so make sure you know it well. Overall, you need to learn the three main types of radiation, what kind of material is sufficient to stop them, the risks and applications associated with radiation, the inverse square law for gamma radiation, and its investigation in required practical 12. See the official specificationhttps://filestore.aqa.org.uk/resources/physics/specifications/AQA-7407-7408-SP-2015.PDF AS and A-Level Physics Specification AQA June 2015 4 June 2022 for more details. Penetrating_power_of_different_types_of_radiation_-_alpha,_beta,_gamma_and_neutrons|frameless|500px Alpha (α) Radiation Nature- 2 protons + 2 neutrons, equivalent to a helium nucleus Range in air- Up to 100mm in air Deflection in a magnetic field- Easily deflected Absorption- Stopped by thin foil and paper Ionisation- Strongly ionising Energy of each particle- Constant for a given source Beta (β) Radiation Nature- β- = electron; β+ = positron Range in air- Up to 1 metre Deflection in a magnetic field- Opposite direction to α particles, more deflection. Absorption- Stopped by approximately 5mm of aluminium Ionisation- Less ionising than α Energy of each particle- Varies up to a maximum Gamma (γ) Radiation Nature- Photon of energy Range in air- Follows inverse square law Deflection in a magnetic field- Not deflected Absorption- Stopped by several centimetres of lead Ionisation- Very weakly ionising Energy of each particle- Constant for a given source References 50%