PHY982. Week Starting date Topic

Transcription

1 PHY982 Week Starting date Topic 1 Jan 7+8 Introduction to nuclear reactions 2 Jan Scattering theory 3 Jan 22 Scattering theory 4 Jan Reaction mechanisms 5 Feb 4+5 Connecting structure and reactions 6 Feb Solving reaction equations 7 Feb R-matrix method 8 Feb Fitting reaction data 9 Mar Accelerators and detectors 10 Mar Spectroscopy 11 Mar Break-up methods 12 Mar 31+ Apr 1 Approximate methods 13 Apr 7+8 Nuclear reactions in the cosmos 14 Apr Students - Projects 15 Apr Students - Projects

2 PHY982 Schedule: Mon+Tue 14:30-16:00 (NSCL Seminar rm) Grading System: Project (25%) + Summary (25%) + Homeworks (50%) Textbook: Nuclear Reactions for Astrophysics, Thompson and Nunes (preliminary versions of chapters to be handed out after lectures) Additional Textbooks: Introduction to Nuclear Reactions, Bertulani and Danielewicz Introductions to nuclear reactions, Satchler Direct nuclear reaction theories, Austern Direct nuclear reactions, Glendenning Nuclear Physics, Lilley Theoretical nuclear reactions, Feshbach Office hours: Tue 16:00-18:00

3 PHY982: Homeworks HW Topic Deadline 1 2 Scattering states and phase shifts Optical model Jan 22 Feb 5 3 Excitation mechanisms Feb 19 4 Data fitting Mar 11 5 Spectroscopy Mar 25

4 Motivation for nuclear reactions hilippe CHOMAZ

5 Motivation for nuclear reactions Les Les chemins chemins de de la la la Nucléosynthèse Nucléosynthèse Big Bang ilippe CHOMAZ Stars

6 hilippe CHOMAZ Les chemins de la Nucléosynthèse Motivation for nuclear reactions

7 Philippe CHOMAZ Les chemins de de la la Nucléosynthèse Motivation for nuclear reactions X-ray Burster

8 ilippe CHOMAZ Les chemins de de la la Nucléosynthèse Motivation for nuclear reactions

9 ilippe CHOMAZ Les chemins de de la la Nucléosynthèse Motivation for nuclear reactions Roseta nebula Super-nova

10 Motivation for nuclear reactions Low energy reactions Beam of radioactive heavy nucleus Direct Reaction γ-ray Indirect Reaction

11 Motivation for Reactions

12 Manifesto: quote from the blue book Unified approaches to nuclei and other mesoscopic systems Nuclei and nuclear matter rooted in fundamental understanding of inter-nucleon interactions Unified approach to reactions that provides a reliable interpretation of the variety of measurements that are/will be performed Extract isospin dependence of thermal, mechanical and transport properties of nuclear matter in nuclei, neutron stars, and supernovae Understand the origin of the elements in the cosmos, and the mechanisms and power sources of stellar explosions such as Supernovae, Novae, Gamma-ray bursts and X-ray bursts

13 Motivation for nuclear reactions Stable nuclei are typically compact. The size is determined by the mass. R m = 2 = drψ *( r) r ψ ( r) r 0 A 1/ 3 Typically r 0= 1.2 fm How to measure the size of the above nuclei

14 Motivation for nuclear reactions Excited States How to study excited states of nuclei?

15 Motivation for nuclear reactions All nuclei have spin (neutrons and proton have spin ½ and -½). If A=even then the total spin is integer. If A=odd then the total spin is half integer. But if N=even and Z=even the total spin is 0. Depending on the spin, the nucleus may not be spherical! Example: electric moments Q ψ l l = e r ψ How do we measure the quadrupole deformation?

16 Motivation for nuclear reactions neutron and proton dripline Weakly bound systems

17 Motivation for nuclear reactions Momentum distributions P r ( ) r r K e ( R ) ik R = Ψ r K r Narrow momentum distributions Large radii

18 Motivation for nuclear reactions Driplines = continuum states

19 Motivation for nuclear reactions : exotic nuclei Very large spatial extension: correct asymptotic behaviour needed finite range effects crucial

20 Motivation for nuclear reactions : exotic nuclei

21 Basic Concepts: nuclear reactions Types of reactions elastic 14 N(α, α) 14 N inelastic 14 N(α, α ) 14 N* deep-inelastic (compound+direct) transfer 14 N(α,p) 17 O breakup 14 N(α,dd) 14 N fusion(capture) 14 N(α,g) 18 F Q-value for a reaction Q = ( M + M M M ) c a A b B 2 Problem: using momentum conservation prove that Conservation Laws energy and momentum angular momentum charge parity (approx) isospin Kinematic selection; Reference frame: lab or c.m. E cm p = M t M + M p t E lab p