Nuclear Reactions Review PHYS40622 Energy Scales in Subatomic - - PDF document

Nuclear Reactions Review

PHYS40622

100 101 102 103 104 105 106 107 108 109 1010 1011 1012 1013 Atomic electron binding energies Nuclear 1st Excited States Energy Released in Fission Relativistic Heavy Ion Collisions Kinetic Energy gained by an electron in 1 Volt

Energy Scales in Subatomic Physics

eV MeV keV GeV TeV Mass-Energy of Electron x rays  rays Mass-Energy of a Nucleon. Coulomb barrier Stellar Fusion temperatures Mass-Energy of a Nucleon Nuclear Flash Temperature

10-24 10-21 10-18 10-15 10-12 10-9 10-6 10-3 100 103 106 109 1012 1015 Saddle to Scission time Lifetimes of excited nuclear states Isomeric states Age of Universe for formation of d Transit of light past nucleus. QGP target ~fm/c

Time Scales in Nuclear Physics

ms fs s year Transit of nucleon in nuclear orbit Mean life of a proton in the Sun

ns

ps b-decay of nuclear ground states Age of Universe as QGP hr Neutron lifetime

Key Theoretical concepts

Partial Wave Expansion – Angular Momentum in HI Collisions (SCO) Quantum Tunnelling - Fission and Thermonuclear Fusion (WKB) Collective vs. Single-particle – Fission Shell-corrected Liquid Drops Macroscopic Concepts applied to Microscopic Systems

• - Temperature and Pressure, Nuclear Equation of State. Friction.

Differential Cross-sections as Probabilities Quantum Interference in Scattering

Key Phenomena

• Fission.
• Fission Isomers.
• Giant Resonances – Dipole and Monopole
• Fusion ( Thermonuclear and near Barrier ).
• Astrophysical r and s processes.
• Deep Inelastic HI Collisions.
• Quark Gluon Plasma (?)

Fission

  

       

2 1 2 / 1 2

) ( 2 2

 





 E V B d F F

fe fp

A Z A a Z a x

s c 2 2

02 . 2  

Giant Resonances

2 / 1 2 GMR

0 

        r m E  

2 sym 2

8 mA ZN a u 

Heavy Ion Cross Sections



  

 

l l l R

T l k

2

) 1 2 (          

CM I I fus

E V R 1

2

 

2 2

) (cos sin ) 1 2 ( 1 

  

  

l l l l i

P e l k d d

l

  



Astrophysical Applications

 

2 22 c

Z Z E

B A G

  

 

3 / 1 2

4        T k E E

B G

v Nn

n

    1

Neutron Capture

Thermonuclear Fusion

Simulation of Au on Au at 200 GeV.

Nuclear Collisions at Relativistic Energies

Nuclear Collision at RHIC

Examinations and Past Papers

• This academic year the exam will follow the standard for

3rd year papers (i.e. Qu. 1 compulsory then choose 2 from Qu. 2-4, resulting in 3 questions in 1 1/2 hours)

• There will be a formula sheet at the start of the paper.

Symbols will have their usual meanings but there will be no definitions given.

• Some overlap with course material means that students

may benefit from attempting selected problems from past papers in the following courses:

• PC462/PYS40622 "Nuclear Reactions" (until 2010)
• PHYS40421 "Advances in Nuclear Physics" (2010-2013)

1 2

2

  M Q

Electron Scattering

Elastic Scattering

           



     sin 2 1 sin 4 cos

4 2 2

M p p Z d d