Download Nuclear and Particle Physics

Nuclear and Particle
Physics
Contact Details
Course Organisers
Daniel Watts (Nuclear Physics)
[email protected]
JCMB Room 8209
Tel: 0131 650 5254
http://www.ph.ed.ac.uk/~dwatts1
Dr Daniel Watts
3rd Year Junior Honours
Course
Mondays & Thursdays 10am
Victoria Martin (Particle Physics)
[email protected]
JCMB Room 4405
Tel: 0131 651 7042
Course handouts will be available on
course web portal after each lecture
(useful as in colour!)
Tutorial arrangements
1 tutorial every two lectures. Class
split into two groups.
Start on Mon 14th January
Mondays 12:10 – 13:00
Room 5327, JCMB
All Astro students
Tuesday 14:00 – 14:50
Room 3317, JCMB
All other students
Group problem solving with Lecturer &
Postdoctoral research assistant
Notes
Notes
Industry
power plants
energy source
materials
tracing
Research
Military
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
My Research interests
Hadron Structure: The structure of the nucleon and of
hadrons in general
Heavy Ion Physics: Quark-gluon plasma, new phases of matter
Using electromagnetic probes (intense photon/electron
beams) to probe matter from scale of atomic nuclei down to
nucleons and quarks. In Germany www.kph.uni-mainz.de, USA
www.jlab.org and Sweden www.maxlab.lu.se. Research topics
include:
Nuclear Astrophysics: Understanding stars, super-novae etc.
• Structure of the proton and neutron
Exotic Nuclei: Nuclei far from stability
• Violent short range nucleon-nucleon interactions in nuclei
Use a wide variety of particle
detection systems
• Three-nucleon forces in nuclei
Hadron Spectroscopy: The search for “glueballs”, “hybrids”,
multiquark states
High intensity
superconducting
electron
Accelerator
(Jefferson Lab)
Large acceptance
magnetic
spectrometers
High precision
magnetic
spectrometers
Hyper pure Ge arrays
Large acceptance
magnetic
spectrometers
Large acceptance high
energy γ detectors
Notes
Course layout
Third year
nuclear force
binding energies
properties
models
radioactivity
NUCLEUS
structure
applications
nuclear reactions
models
astrophysics
medicine
industry
…
Fourth year
Notes
Nuclear Physics
Course Outline
• Introduction and basic concepts
Brief historical overview
The nucleus and its constituents
Nomenclature
The forces of nature
Basic concepts of quantum mechanics
• Nuclear properties
External: mass, charge, size, mass and charge distribution
Internal: angular momentum, spin, parity, magnetic moment
excited states
• Nuclear structure
Masses and binding energies
Semi-empirical mass formula
The beta stability valley
Properties of nuclear forces
• Nuclear models
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
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
Notes
Notes
Brief historical overview
In search of the building blocks of the universe…
Greek philosophers
earth
4 building blocks
5th BC - Democritus
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
Notes
Notes
~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
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)
Clear experimental evidence that atoms contain
electrons – where are they?
Heisenberg ⇒ simplest atom = H
“plum pudding model”
use α particles (positively charged) on golden foil
+ve α’s pushed a little to the side
by +ve charge of atom
mass
charge
He ~ 4 H
C ~ 12 H
O ~ 16 H
….
He = 2 H
C =6H
O =8H
….
observed
some α’s deflected
backwards to 180o
!!
⇒ hypothesis of neutral particle
in nucleus with m ~ mp
1932 Chadwick discovers the neutron
3 building blocks
electron + proton + neutron
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”
its nucleus = proton
1920 Aston’s mass spectrograph ⇒ measure masses of atoms
-ve electrons embedded in
+ve charge uniformly distributed
over atomic volume
expected
+Ze
Nucleus = protons + neutrons
NUCLEAR PHYSICS
(10-15 m)
1934 Joliot, Curie - Artificial radioactivity
1940 Flerov, Petrjak - Spontaneous fission
Notes
Notes
Origin of nuclear matter (Background)
Universe goes through
superfast inflation
10-43s
10-32s
1027 oC
Post inflation – soup of
electrons, quarks and
other particles
10-6s
1013 oC
Quarks clump into protons
and neutrons
102 s
108 oC
Superhot fog (protons
and electrons not yet bound
into atoms). Primordial
nucleosysnthesis (up to 4He)
3x105 yr
1x109 yr
15x109 yr
Energy, time and density scales
105 oC
-200 oC
-270 oC
Electrons combine with
protons and neutrons to
form atoms (H, He)
Star/Galaxy formation
synthesis of heavier nuclei
First stars die and eject
heavy nuclei into space –
further star formation (and
planets)
Typical energy scale in
nuclei (MeV) is much
higher than in atomic case
(eV). Lifetimes of excited
states are typically of
order 10-12 s compared
with 10-8 s for atomic
physics
Nuclei are dense objects:
1cm3 has mass ~ 2.3x1011
kg (equivalent to 630
empire state buildings!!)
The collisions of nucleons in the nucleus are rarely of
sufficient energy to excite the protons/neutrons
∴ they are a very effective degree of freedom to
describe nuclei
White Dwarf
100
Time
Neutron star
Solid state
water
105
1010
Black hole
3
1015 g/cm
density
Nuclear matter