Download Nuclear and Particle Physics

Nuclear and Particle
Physics
Dr Daniel Watts
3rd Year Junior Honours
Course
Mondays & Thursdays 10am
Industry
power plants
energy source
materials
tracing
Military
Research
condensed matter
element analysis
(bio)chemistry
nuclear weapons
Nuclear
Physics
Medicine
Archaeology
& Geology
computed tomography
magnetic resonance imaging
radiation therapy
dating
analysis
Astrophysics
energy production in stars
nucleosynthesis of elements
LIFE
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, supernovae etc.
Course layout
Third year
nuclear force
binding energies
properties
models
radioactivity
NUCLEUS
structure
applications
nuclear reactions
astrophysics
medicine
industry
…
models
Fourth year
Nuclear Physics
Course Syllabus
• Introduction and basic concepts
(lecture 1 & 2)
Brief historical overview
The nucleus and its constituents
Nomenclature
The forces of nature
Basic concepts of quantum mechanics
• Nuclear properties
(lecture 3 & 4)
External: mass, charge, size, mass and charge distribution
Internal: angular momentum, spin, parity, magnetic moment
excited states
• Nuclear structure
(lecture 5 )
Masses and binding energies
Semi-empirical mass formula
The beta stability valley
Properties of nuclear forces
• Nuclear models
(lecture 6, 7 and 8)
Liquid drop model
Shell model and evidence for shell structure
Single particle features
Magic numbers, spin-orbit coupling
Predicted angular momenta of nuclear ground states
Collective model. Vibrational and rotational states
• Nuclear instability
Occurrence and stability of nuclei
α- β- γ- decay modes
(lecture 9)
Suggested textbooks
J. Lilley
Nuclear physics
Principles and applications
John Wiley and Sons, 2001
Clear and concise. Not too advanced, makes a very good
starting point. Interesting chapters on applications
W.N. Cottingham and D.A Greenwood
An introduction to nuclear physics
Oxford Science Publications, 1997
Nicely concise and still rich in content.
K.S. Krane
Introductory nuclear physics
John Wiley and Sons, 1988
Very didactic and clear.
The textbook for the more advanced, dedicated student.
R. Eisberg and R. Resnick
Quantum 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
P.E. Hodgson, E. Gadioli and E. Gadioli Erba
Introductory nuclear physics
Oxford Science Publications, 1997
Very comprehensive + somewhat more advanced.
Deeper mathematical treatment
Brief historical overview
In search of the building blocks of the universe…
Greek philosophers
4 building blocks
5th BC - Democritus
earth
water
atomic hypothesis
18th-19th century Lavoisier, Dalton, …
put atomic hypothesis on firm basis
distinction between compounds and pure elements
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
α deflected less than β ⇒ α must have larger mass
γ not deflected ⇒ uncharged
air
fire
~1900 Rutherford investigates new radiations
α and β emissions change nature of element
α‘s charge = +2e α’s mass ~ 4H
β radiation = electrons
γ = electromagnetic radiation (photons)
1911 Rutherford tests Thomson’s model of the atom
Clear experimental evidence that atoms contain
electrons – where are they?
“plum pudding model”
-ve electrons embedded in
+ve charge uniformly distributed
over atomic volume
use α particles (positively charged) on golden foil
expected
+ve α’s pushed a little to the side
by +ve charge of atom
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 came
back and hit you”
observed
some α’s deflected
backwards to 180o !!
Conclusion:
all +ve charge (and ~all mass) concentrated in tiny region at the centre
Concept of atomic NUCLEUS is born !
Atom = nucleus + electron
-e
planetary model of atom
(10-10 m)
Heisenberg ⇒ simplest atom = H
+Ze
its nucleus = proton
1920 Aston’s mass spectrograph ⇒ measure masses of atoms
mass
charge
He ~ 4 H
C ~ 12 H
O ~ 16 H
….
He = 2 H
C =6H
O =8H
….
⇒ hypothesis of neutral particle
in nucleus with m ~ mp
1932 Chadwick discovers the neutron
3 building blocks
electron + proton + neutron
NUCLEAR PHYSICS
Nucleus = protons + neutrons
(10-15 m)
Are protons and neutron the ultimate building blocks?
Are they fundamental particles?
Energy and density scales
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!!)
White Dwarf
Solid state
100
water
105
Neutron star
1010
Black hole
3
1015 g/cm
density
Nuclear matter