Flashcards
Pair Production and annihilation
Cards in this deck (9)
- 1Why do Positrons and electrons cure in different directions during pair production in a magnetic field?They curve in opposite ways because of there charge. An electron has a negative charge so it will curve to the opposite side to a positron as that has a positive charge.
- 2Why during pair production do particles spiral inwards instead of outwards?Particles spiral inwards because they are losing energy and not gaining energy.
- 3What happens when antimatter and matter meet?They annihilate one another and release the energy as photons.
- 4How are positron emitting isotopes formed?They form when a stable isotope in the path of a beam of protons. Some of the nuclei in the isotope absorb the extra protons and become unstable. They are then called Positron emitting isotopes.
- 5What is Diracs theory?Antiparticles and particles annihilate when they meet.
Antiparticles and the corresponding particle have exactly the same mass and energy.
The only difference between the two particles is that they have opposite charges. - 6What did Dirac predict?He predicted pair production. This is when a photon with enough energy passing near to a nucleus or an electron can change into a particle - antiparticle pair which would then separate from each other.
- 7What is one mega electron volt equal to?1.6 x 10 to the -13 Joules.
You can calculate this using E=mc⇧2 - 8How do we work out the minimum energy of each photon during annihilation?Plancks constant x minimum frequency
- 9What is the minimum energy?This is the smallest amount of energy needed to create a particle. For example if you had the energy of each photon to be 0.511MeV then the total energy is 1.022MeV which is enough to create a positron and an electron
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- Flashcards detailing everything there is to know about pair production, annihilation and antiparticles.
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- Tom Micklethwaite
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