NUCLEAR ENGINEERING by HC120717113911

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									  NUCLEAR
ENGINEERING
 The Fundamentals
                      The Particles
   Electron
       Positron
       Negatron (beta)
   Proton - positive charged
   Neutron-neutral charge
       Unstable when not bound in a nucleus
            Decays to a proton and a b
   Photon - wave/particle duality,
   Neutrino - used to balance energy and
    momentum on nuclear reactions
         Symbols, Mass Charge
            Symbol   Mass (amu) Charge

Proton          1    1.007276      +1
                p
                1
                1
Neutron
            n   0
                     1.008665      0

Beta        b   0
                1
                     5.485 x10-4   -1


Photon
               0    0             0
                0

Neutrino    n        0             0
          Structure
Nucleus are the protons and
neutrons both.
                     Nucleons are either
                     protons or neutrons

                       Atomic number is = total
                       number of protons Z

                      Neutron number = total
                      number of neutrons N

                Atomic mass number sometimes
                called nucleon number A
Your First Equations


          ZNA
              A
          X   Z
                 Isotopes
   Atoms with the same number of of protons
    but different numbers of neutrons are
    Isotopes
   Atomic weight (grams/gmole) - M
   Atomic weight of a mixture of isotopes is
    when isotopic abundance is in %

              M 
                          i M i 
                     i
                          100
          Avogadro’s number
   Avogadro’s number is the number of anything in
    a mole


                      24 things
                                                 Qu i ckTi m e™ a nd a



      N A  0.602310
                                     TIFF (Un co mp res se d) de c omp res so r
                                        a re ne ed ed to se e th is pi c tu re.




                          mole
   amu- atomic mass unit - the mass of any atom is
    numerically equal to the atomic weight of the
    atom in question
            Mass and Energy
   Mass at rest           Mass of a body in motion
   Etotal=m0c2            Etotal=mc2 where

                                       m0
                               m
                                        v2
                                      1 2
                                        c
                           Kinetic energy

                                    1
                               E  m0v 2
                                    2
               Particle wavelength
        For Photons use      1.5



                                1



             E  hv           0.5



                                0                                                         Series2


     h is Planck’s constant
                                     1   11   21   31   41   51   61   71   81   91 101

                              -0.5


        and v is frequency     -1

                            -1.5
              Excited states
   Ground state           An atom cannot
                            remain in an
                            excited state
                            forever. It
                            eventually
                            decays (returns
                            to its ground
                            state)when the
                            transition occurs
                            a photon is
                            emitted.
Stability



                      Quic kTime™ and a
            TIFF ( Uncompressed) decompr essor
               ar e need ed to s ee this picture.
Decay schemes




          QuickTime™ and a
 TIFF (Uncompressed) decompre ssor
    are neede d to see this picture.
                    Half-Life
   The decay rate is
    called activity - a
   Units are Ci or
    Bq(dis/sec)
   1Ci=3.7x1010 Bq                                  QuickTime™ an d a
                                            TIFF (Uncompressed) decompressor
                                               are need ed to see this p icture .


   Decay constant is l
          ln 2
        l
           t1/ 2
                           Image from;www.ehrs.upenn.edu/training/nuc_med/intro.html
         Time Rate of Change
   Set up the differential equation
   Simple case radioactive decay
   Change in the number of atoms per time =
    production-destruction

              dn(t)  ln(t)dt
                              lt
               n(t)  n 0e
        Production in a nuclear
               reactor
   Change in the number of atoms per time = production-
    destruction

              dn
                  ln  R
              dt
                           R
              n  n 0e   e 
                       lt
                             1  lt

                             l
   When we learn more about neutron R is better defined.




         Nuclear Reactions
                        Conservation of
A  B C  D
 q
 r
     s
     t
             u
             v
                 w
                 x          Nucleons
q s u w                  Charge
                            Momentum
rt v x                   Energy
                Decay Chain
   AB C
   Change in the number of B atoms per time =
    production from A -decay from B to C
         dnB
                lB n B  lA n A
          dt
         dnB                            lB t
                l B n B  l A n A 0e
          dt
                             lA n A 0  lA t  lB t
                      lB t
         n B  n B 0e 
                            lB  lA
                                        e  e 
                   Binding Energy
                                         The energy
                                          necessary to break an
                                          atom apart - Hold the
                                          nuclear together
         QuickTime™ and a
TIFF (Uncompressed) decompressor
                                         Mass defect is the
   are need ed to see this picture.
                                          difference in the
                                          measured mass from
                                          the mass you would
                                          get if you summed up
                                          the parts
               The calculations
    Mass defect                   Binding Energy
  Z M p  me  NM n  M A
                                                  Mev
M p  me   M(H1 )
                 1                   BE    931
                                                  amu
  Z H1  NM n  M A
        1


    Look up MA on a Chart of
     the nuclides.       
    Masses must be isotope
     specific
    Use Web or come in a
     use a book in my office
                              Q value
   Q=(initial -final) 931Mev/amu
           + exothermic rest mass is converted into kinetic energy
           - endothermic kinetic energy converted into rest mass
   Use of neutral atoms for binary reactions
       conserve charge
                                                      1
                 Proton    a proton + electron( H1 )
                 Alpha       a helium atom ( He 4)
                                                  2




                                   
                                  
                                Atom Density
                                                 The number of atoms
                                                  per unit volume
                                                 General equation
               QuickTime™ an d a
      TIFF (Uncompressed) decompressor
         are need ed to see this p icture .




                                                           N A
                                                  N
                                                             M
Electron density map from
www.geo.arizona.edu/ xtal/geos306/fall04-5.htm
 Variations of a Theme
   n i N A      n is for molecular
N                density (H2O it is 2 for
       M          Hydrogen 1 for
    i N A       Oxygen)
N                is atom %
       M         w is weight %
   w i N A           Chemical formula
N
                  
                      XmYn
       M             mM x
              wx              100
                   mM x  nM y

								
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