Physics [4] Revision: Radiation

Physics [4] Revision: Radiation

1. Radiation Types

   • Alpha
     • Cannot penetrate 1cm of Paper
     • Helium Particle: Two Protons and Two Neutrons
     • Causes the most harm if IN body; like a wrecking ball
       • Alexander Linkenov
     • Americanium is used in Smoke alarms
   • Beta
     • Can Penetrate 1cm of Paper but is stopped by Aluminium
     • An Electron
     • Is used in paper mills to determine thickness
   • Gamma
     • Cannot penetrate thick lead
       • Electromagnetic wave: Highest Frequency
     • Used to sterilize medical equipment
     • Given off by radioactive materials: Harder to control
     • Can be used to treat cancers
     • Both are Ionising and have similar wavelengths

2. X-rays

   • Electromagnetic Wave: 2nd Highest Frequency
   • Ionising radiation given off by the radiation can be absorbed by skin and bone depending on the density.
     • They usually pass through the skin and flesh
     • Absorbed by bone
       • So Bone images are seen making it easier to see fractures etc
   • X-Ray Machine
     • 'manufactures' X rays
       • A hot Cathode emits electrons
         • These are attracted to a tungsten anode
           • When they collide the kinetic energy is transferred into heat and X-Rays
     • Can control the intensity and energy the X-Ray has

3. Fission and Fusion

   • Fission
     • Common
     • Splitting of nuclear particles which creates some energy
     • Chain Reaction wherin the reaction keeps on going
     • Cheaper option
     • Utilised Uranium 235
       • Joins with U-236 which is Unstable to begin a chain reaction
   • Fusion
     • Joining of Nuclear Atoms
     • Reactions that take part in the SUN
     • Requires a LOT of HEAT: 10,000,000 OC
       • This makes it impractical as no material can withstand the pressure nor create such environment
         • Cannot be controlled safely
       • Experimental reactors are in construction
         • One is being created in Oxford University
         • The largest is JET (Joint European Torus)

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