Nuclear and ParticlePhysics
3rd Year Junior HonoursCourse
Mondays & Thursdays 10am
Dr Daniel Watts
NuclearPhysics
Medicinecomputed tomography
magnetic resonance imagingradiation therapy
Militarynuclear weapons
Researchcondensed matterelement analysis(bio)chemistry
Industrypower plants
energy sourcematerialstracing
Astrophysicsenergy production in stars
nucleosynthesis of elements
LIFE
Archaeology& Geology
datinganalysis
Today’s nuclear physics research
Hadron Structure: The structure of the nucleon and of hadrons in general
Hadron Spectroscopy: The search for “glueballs”, “hybrids” and multiquark states (eg. Pentaquark)
Heavy Ion Physics: Quark-gluon plasma, new phases of matter
Nuclear Astrophysics: Understanding stars, super-novae etc.
properties
NUCLEUS structure
models
radioactivity
nuclear force
nuclear reactions
models
binding energies
applications
astrophysicsmedicineindustry
…
Course layout
Third year
Fourth year
• Introduction and basic concepts (lecture 1 & 2) Brief historical overviewThe nucleus and its constituents NomenclatureThe forces of natureBasic concepts of quantum mechanics
• Nuclear properties (lecture 3 & 4) External: mass, charge, size, mass and charge distributionInternal: angular momentum, spin, parity, magnetic momentexcited states
• Nuclear structure (lecture 5 ) Masses and binding energiesSemi-empirical mass formulaThe beta stability valley Properties of nuclear forces
• Nuclear models (lecture 6, 7 and 8) Liquid drop model Shell model and evidence for shell structureSingle particle featuresMagic numbers, spin-orbit couplingPredicted angular momenta of nuclear ground statesCollective model. Vibrational and rotational states
• Nuclear instability (lecture 9) Occurrence and stability of nuclei α- β- γ- decay modes
Nuclear PhysicsCourse Syllabus
Suggested textbooks
K.S. Krane
Introductory nuclear physicsJohn Wiley and Sons, 1988
J. LilleyNuclear physics Principles and applicationsJohn Wiley and Sons, 2001
Clear and concise. Not too advanced, makes a very good starting point. Interesting chapters on applications
R. Eisberg and R. ResnickQuantum physics of atoms, molecules, solids,nuclei and particles John Wiley and Sons, 1985
Exceptionally clear + very didactic. Optimum for review of quantum ideas in atomic & nuclear physics
Very didactic and clear. The textbook for the more advanced, dedicated student.
W.N. Cottingham and D.A Greenwood
An introduction to nuclear physicsOxford Science Publications, 1997
Nicely concise and still rich in content.
P.E. Hodgson, E. Gadioli and E. Gadioli Erba
Introductory nuclear physics
Oxford Science Publications, 1997
Very comprehensive + somewhat more advanced. Deeper mathematical treatment
In search of the building blocks of the universe…
Greek philosophers earth
water
4 building blocks air
fire
Brief historical overview
1896 Mendeleev
92 building blocks(chemical elements)
1H, 2He, …92U
1896 Becquerel discovers radioactivity
⇒ emission of radiation from atoms⇒ 3 types observed: α, β and γ
α and β deflected in opposite direction ⇒ opposite charge
γ not deflected ⇒ unchargedα deflected less than β ⇒ α must have larger mass
18th-19th century Lavoisier, Dalton, …put atomic hypothesis on firm basisdistinction between compounds and pure elements
5th BC - Democritus
atomic hypothesis
1911 Rutherford tests Thomson’s model of the atom
~1900 Rutherford investigates new radiations
α and β emissions change nature of elementα‘s charge = +2e α’s mass ~ 4H β radiation = electronsγ = electromagnetic radiation (photons)
-ve electrons embedded in +ve charge uniformly distributed over atomic volume
“plum pudding model”
use α particles (positively charged) on golden foil
expected observed+ve α’s pushed a little to the side
by +ve charge of atomsome α’s deflected backwards to 180o !!
In Rutherford’s own words:
“…it was as incredible as if you had fired a 15-inch shell at a piece of tissue paper and it cameback and hit you”
Clear experimental evidence that atoms contain electrons – where are they?
1932 Chadwick discovers the neutron
3 building blockselectron + proton + neutron
Nucleus = protons + neutrons
NUCLEAR PHYSICS(10-15 m)
Atom = nucleus + electron
+Ze
-e
(10-10 m)
planetary model of atom
Heisenberg ⇒ simplest atom = H its nucleus = proton
1920 Aston’s mass spectrograph ⇒ measure masses of atoms
mass chargeHe ~ 4 H He = 2 HC ~ 12 H C = 6 HO ~ 16 H O = 8 H
…. ….
⇒ hypothesis of neutral particle in nucleus with m ~ mp
Conclusion:all +ve charge (and ~all mass) concentrated in tiny region at the centre
Concept of atomic NUCLEUS is born !
Are protons and neutron the ultimate building blocks?Are they fundamental particles?
Energy and density scales
100 1010 1015105
Solid stateWhite Dwarf
Neutron star Black hole
Nuclear matterwater
g/cm3
density
Typical energy scale in nuclei (MeV) is much higher than in atomic case (eV)
Nuclei are dense objects:1cm3 has mass ~ 2.3x1011
kg (equivalent to 630 empire state buildings!!)