1. Nuclear Physics
PHY 361

2. Outline history structure of the nucleus binding energy radioactivity
nuclear binding force
liquid drop model
shell model – magic numbers
binding energy
chart of nuclides
line of stability, drip line, island of stability
radioactivity
,, decay
fission, fusion
I will start with a brief reminder of where we were last, and explain the different options available for polarizing the beam. Then I will go on and show the progress we have made towards a feasible design of the novel splitter polarizer geometry. We have also done new detailed simulations of the different designs and recalculated the costing of each for comparison. Based on this new information, we have arrived at a choice for the baseline design.

3. History Becquerel – discovered radioactivity (1896)
Rutherford – nuclear model
classified ,, radiation,  particle = 4He nucleus
used  scattering to discover the nuclear model
postulated ‘neutrons’ A=Z+N (1920); bound p+ e- state?
Mosley – studied nucleus via X-ray spectra
correlated (Z = charge of nucleus) with periodic table
extra particles in nucleus: A = Z + ?
Chadwick – discovered neutron (1932)
Pauli – postulated neutral particle from -decay (1930)
Fermi – theory or weak decay (1933) ‘neutrino’
Fission – Hahn, Strassmann, (&Meitner!) (1938)
first reactor (chain reaction), Fermi (1942)
Bohr, Wheeler – liquid drop model
Mayer, Jensen – shell model (1949)
Hofstadter – electron scattering (1953-)
measured the charge density of various nuclei
discovered structure in the proton (not point-like particle)

4. Nuclear potential Hofstadter, electron scattering
strong force + Coulomb repulsion (p-p)
~ finite square potential
hard core – const. density
Hofstadter, electron scattering

5. Liquid drop model of the nucleus
constant density like a liquid R = R0 A1/3 where R0 ~ 1.2 fm  = A / (4/3 R3) = 1014 g/cm3 !
finite square potential
p,n act as free particles inside of drop
states filled to Fermi energy
‘surface tension’
normally prevents breakup
excitation can induce split into smaller drops with lower overall energy

6. Shell model of the nucleus
1949 – M. Mayer, J.H.D. Jensen
similar to atomic orbitals
quantized angular momentum
energy levels
multi-particle wave function
difference:
no ‘central’ potential (nucleus)
effective finite square potential
complicated nuclear force
strong dependence on spin
two particles: p, n
more types of decays
nucleus
atom

7. Chart of Nuclides – binding energy
AZXNq ex. 1H, 2H, 3He, 4He
A = Z + N = # protons + # neutrons
B = Z MHc2 + N mnc2 - MAc2
nuclides – Z,N
isotope – constant Z (‘same place’)
isotone – constant N (isoto‘n’e)
isobar – constant A (‘same weight’)
isomer – excited state or nuclide

8. Chart of Nuclides – lifetime
magic numbers

9. Chart of Nuclides – decay mode
magic numbers
stable nuclide
- decay
, electron capture
decay
p decay
n decay
spontaneous fission

10. Chart of Nuclides – island of stability
magic numbers

11. Nuclear decay modes: Z N ++ decay - decay (isobar) + decay (isobar)
 electron capture (isobar)
p decay (isotone)
n decay (isotope)
 decay (isomers)
electron conversion (EC)
spontaneous fission (SF)
double beta decay (2)
neutrino-less double beta decay (0)
beta-delayed n,p, decay
ISOBARS
ISOTONES
ISOMERS
ISOTOPES Z N

12. Alpha-decay

13. Beta-decay