Fundamentals of Radiation
The process of emission of radiation or particles
Atomic Model (Main Particles)Nucleus (Nucleons)Proton, p, positive chargemass = 1.67262x10-27 kgNeutron, n, no chargemass = 1.67929x10-27 kgElectron Shell/CloudElectron, e, negative chargemass = 9.10939x10-31 kg
Atomic (Bohr) Model
Other Basic ParticlesPhotonElectromagnetic waveNo mass or chargeNeutrino (Antineutrino)No mass or chargeAppears during decay of certain nucleiMany more that Physicists like
Atomic DefinitionsAtomic Number, ZNumber of Protons/ElectronsAtomic Mass Number, ATotal Number of NucleonsAtomic WeightMass of a Neutral Atom Relative to the Mass of 12CElementNuclide with Unique Atomic NumberIsotopesNuclides with Same Atomic Number but Different Atomic Mass Numbers
Common Isotopeshttp://www.eccentrix.com/
Atomic DefinitionsIsotope Identification or X-A ActivityNumber of disintegrations (decays) per unit timeHalf-LifeTime for half of the material to decay away
Radiation Decay
Radiation UnitsBecquerel, BqOne disintegration per secondRate at which radiation of some type is emitted from a collection of isotopes Curie, Ci3.7x1010 BqAmount of radiation emitted from 1 g of Ra-226
Common Radioactive DecayAlpha, a++Helium Nucleus (4 n, 2 p)Captures 2 eBeta, b-ElectronPositron, b+Gamma, gPhoton
Atomic Stability CurveAlpha DecayBeta DecayPositron Decay
Decay Chains
3 Things to Reduce RadiationDistanceShieldingTime
Distance: Inverse Square Law
Visualizing Distance
Shielding: Attenuationm is a function of radiation energy and shielding material
Shielding Radiation
Visualizing Shielding
Time: Duration of Exposure
Common RadioisotopesCarbon-14, Organic MaterialPotassium-40, BananasTechnetium-99, Medical DiagnosisCesium-137, Industrial GaugesLead-210, GroundRadium-226,-228, Brazil NutsUranium-234,-235,-238, GroundThorium-232, GroundPlutonium-238, PacemakersAmericium-241, Smoke Detectors
Examples and Problems 1.2Pumped Storage Scheme:Reservoir Containing 6.7 million m3 H2O 500 m above the Lower ReservoirCan Supply 1800 MWeAssume No LossesHow Long Can the Plant Remain in Operation?
Examples and Problems 1.2SolutionFind the Total Potential EnergyMass = Volume * Density r = 1000 kg/m3, m = 6.7x109 kgPE = Mass * Height * Gravity (9.81 m/s2)PE = 32.8x1013 JOperational Time = PE/PowerOT = 5 hours
Examples and Problems 1.2Other Problems using Same EquationsWhat is the Volume of the Upper Reservoir for a Set Power Supply and Operational Time?Account for Additional Power Losses using Efficiency TermsCompare Reservoir Sizes and Heights for Desired Power RatingsAdditional AnalysisEnergy Costs to Fill Upper Reservoir versus Revenue Generated from Energy Produced
Radiation Decay ExampleIf you had a vial containing 9x1012 Bq each of carbon-14 and Bq of tritium, what would the activity be 100 years later? How many grams of each would be in the container?(The isotopes decay into nitrogen-14 and helium-3, respectively)
Radiation Decay Example
IsotopeA(100y)N(100y)m(100y)3H3.2x1010 Bq5.7x1011 atoms2.8 pg14C8.9x1012 Bq7.4x1016 atoms1.5 mg