Annihilation 0.0 / 5 ? PhysicsParticle physicsASAQA Created by: tahliaDCreated on: 13-10-15 13:35 What happens when a particle and an antiparticle meet? Annihilation 1 of 10 What happen during annihilation? All the mass of the two particles in converted back into energy in the form of two gamma ray photons 2 of 10 Why don't you get antipaticles in ordinary matter? They can only exist for a fraction of a second before annihilation occurs 3 of 10 Give the equation for the minimum energy of the photon produced Emin=Eo 4 of 10 Explain the equation It is an particle-antiparticle pair which both have a rest energy of Eo so the two photons produced must share 2Eo between them or Eo each 5 of 10 What does PET stand for? positron- emission tomography 6 of 10 Describe how a PET scanner works a positron emitting isotope is placed into the bloodstream. The scanner then detects the gamma rays produced by the electron-positron annihilation. 7 of 10 Why are these Gamma ray easy to distinguish between the others? They are always produced in pairs travelling in opposite directions 8 of 10 What is the radiation detected by? The scintillator 9 of 10 How does a scintillator form an image? It contains scintillation crystals which detect the gamma rays and produce flashes of light. This light is detected and forms an image 10 of 10
Comments
No comments have yet been made