Nuclear Reactions Review PHYS40622 Energy Scales in Subatomic - PDF document

Nuclear Reactions Review PHYS40622

Energy Scales in Subatomic Physics 10 13 10 12 TeV 10 11 Relativistic Heavy Ion Collisions 10 10 10 9 GeV Mass-Energy of a Nucleon Mass-Energy of a Nucleon. 10 8 Coulomb barrier Energy Released in Fission 10 7 Nuclear Flash Temperature Nuclear 1 st Excited States  rays 10 6 MeV Mass-Energy of Electron 10 5 10 4 Stellar Fusion temperatures 10 3 keV x rays 10 2 Atomic electron binding energies 10 1 10 0 eV Kinetic Energy gained by an electron in 1 Volt

Time Scales in Nuclear Physics Mean life of a proton in the Sun 10 15 10 12 10 9 year 10 6 hr 10 3 Neutron lifetime Age of Universe for formation of d 10 0 s 10 -3 b -decay of nuclear ground states m s 10 -6 Age of Universe as QGP Isomeric states 10 -9 ns ps 10 -12 Lifetimes of excited nuclear states 10 -15 fs 10 -18 Saddle to Scission time 10 -21 Transit of nucleon in nuclear orbit Transit of light past nucleus. QGP target ~fm/c 10 -24

Key Theoretical concepts Quantum Interference in Scattering Differential Cross-sections as Probabilities Partial Wave Expansion – Angular Momentum in HI Collisions (SCO) Macroscopic Concepts applied to Microscopic Systems -- Temperature and Pressure, Nuclear Equation of State. Friction. Collective vs. Single-particle – Fission Shell-corrected Liquid Drops Quantum Tunnelling - Fission and Thermonuclear Fusion (WKB)

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 2 a Z Z   c x 0 . 02 2 a A A s  2 1 / 2     2 B ( V E )   2 d     2      fp fe 1 F F

Giant Resonances 8 a ZN u  sym 2 2 mA 1 / 2        E GMR  0  2 m r  

Heavy Ion Cross Sections 1  2    l d      i ( 2 l 1 ) e sin P (cos ) l  l l 2 d k  l 0    l     ( 2 l 1 ) T R l 2 k  l 0    V    2 I   R 1 fus I   E CM

Astrophysical Applications Thermonuclear Fusion      2 2 c 2 E Z Z G A B   1 / 3   2 E k T    G B E 0  4  Neutron Capture 1   N n v   n

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)

Electron Scattering 2 Q  Elastic Scattering 1  2 M    2 Z cos   d       2 p d  2 4 0 4 p sin 1 sin     0   M