ADVANCED NUCLEAR ASTROPHYSICS - 2020/1

Module Overview

This module aims to provide an advanced level understanding of the physics of stars and nuclear astrophysics. In particular, the course will provide an understanding of advanced nucleosynthetic pathways, an analytical underpinning of resonant reaction rates, together with the experimental techniques involved in their determination.

Module provider

Physics

Module Leader

LOTAY Gavin (Physics)

Number of Credits: 15

ECTS Credits: 7.5

Framework: FHEQ Level 6

Module cap (Maximum number of students): N/A

Module Availability

Semester 2

Prerequisites / Co-requisites

This module assumes knowledge equivalent to PHY2067 Nuclear and Particle Physics, and PHY2071 introduction to Astronomy.

Module content

• Overview of nuclear landscape and the importance of stars in the formation of the chemical elements

The Physics of Stars

• Basic observations and stellar parameters – Hertzsprung-Russell diagram, Mass-Luminosity relationship and colour
• Gravitational contraction and hydrostatic equilibrium
• Main Sequence stellar structure
• Late stellar evolution and compact astronomical objects

Nucleosynthesis paths

• Motivation for neutron-capture nucleosynthesis process. Differences between stable and explosive nucleosynthesis.
• Slow neutron capture process: nucleosynthetic path, physical properties, astrophysical site
• Rapid neutron capture process: nucleosynthetic path, physical properties, astrophysical site
• Other nucleosynthetic process (gamma-process, rp-process) of relevance.
Experimental determination of Resonant Stellar Reaction Rates

• Basic overview of nuclear reactions: energetics; Q-values, reaction cross sections and concept of particle-emission thresholds (Sn, Salpha and Sp)
• Experimental determination of Q-values – Mass measurements with Ion Penning Traps and Heavy-ion Storage Rings.
• Resonant reactions with neutrons and charged particles – concept of broad and narrow resonances.
• Analytical formalism for narrow and broad resonance contributions to stellar reaction rates – key nuclear physics properties of resonance energy, spin and particle partial widths.
• Experimental techniques for the determination of resonant stellar reaction rates –
1. Direct methods using recoil mass spectrometers and need for radioactive ion beams. Direct methods using neutrons and time-of-flight facilities: (n,gamma) as well as (n,p) for vp-process.
2. Indirect methods: (i) Charge exchange reactions, such as (3He,t), and angular distributions (ii) γ-ray spectroscopy; role of angular distributions, lifetimes and mirror symmetry, (iii) β-delayed particle decay spectroscopy; selection rules and logft values, (iv) Measurements of alpha-particle decay branches using transfer reactions and (iv) Spectroscopic factors from (d,p) and (3He,d) transfer reactions and principles of scattering theory.
3. Broad resonance studies and R-Matrix theory: example of 18F(p,alpha) and its role in the destruction of the potential cosmic gamma-ray emitter 18F in novae.

Contemporary Nuclear Physics Facilities

• Overview of nuclear physics research worldwide and types of facilities available.
• Nuclear experiment datasets and their manipulation.

Assessment pattern

Alternative Assessment

None

Assessment Strategy

The proposed assessment strategy for this module will involve:

• 30% for a take-home class test of exam-style questions. Feedback will be provided. Coursework set in week 5, to be submitted after Easter break (typically week 8)
• 70% for a final, 1.5 hour closed book examination where students will answer 2 questions from a set of 3.

Module aims

• Provide an understanding of the underlying physics behind the formation of stars and stellar evolution, including computational modelling.
• Provide an understanding of nucleosynthesis paths: s-process, r-process and p-process; the physical properties and their astrophysical sites;
• Provide an understanding of nuclear reaction networks and their relevance in stellar modelling, including contemporary computational tools
• Provide an analytical treatment of resonant stellar reaction rates for both narrow and broad resonance contributions, together with a detailed understanding of the modern experimental techniques used in obtaining the key nuclear physics information required.
• Provide an understanding on current experiment nuclear facilities and the types of datasets that are in place.

Learning outcomes

Methods of Teaching / Learning

The learning and teaching methods include:

Formal lecture based module:
• 33 hours of lectures/tutorials split approximately in 20h of lectures, 11h of tutorials and 2h of computational sessions.

Indicated Lecture Hours (which may also include seminars, tutorials, workshops and other contact time) are approximate and may include in-class tests where one or more of these are an assessment on the module. In-class tests are scheduled/organised separately to taught content and will be published on to student personal timetables, where they apply to taken modules, as soon as they are finalised by central administration. This will usually be after the initial publication of the teaching timetable for the relevant semester.

Reading list

https://readinglists.surrey.ac.uk
Upon accessing the reading list, please search for the module using the module code: PHY3059

Other information

None

Programmes this module appears in

Please note that the information detailed within this record is accurate at the time of publishing and may be subject to change. This record contains information for the most up to date version of the programme / module for the 2020/1 academic year.