EXPLOSIVE STELLAR PHENOMENA - 2023/4

Module Overview

This module aims to provide an advanced level understanding of explosive nuclear astrophysics and the physics of stars. In particular, the course will provide an analytical underpinning of resonant reaction rates, together with the experimental techniques involved in their determination, as well as a theoretical treatment of nuclear reactions and celestial objects.

Module provider

Mathematics & Physics

Module Leader

LOTAY Gavin (Maths & Phys)

Number of Credits: 15

ECTS Credits: 7.5

Framework: FHEQ Level 7

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

Module Availability

Semester 2

Prerequisites / Co-requisites

This module will assume prior knowledge equivalent to PHY2067 Nuclear and Particle Physics (BSc Physics Year 2). If you have not taken this module, you should consult the module descriptor.

Module content

Indicative content includes:

• Introduction to EPAP, overview of nuclear landscape and the importance of stars in the formation of the chemical elements

• 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

• Classical Novae – Observations (UV/IR spectra and presolar grains), explosive hydrogen burning and novae nuclear reaction networks


• Core-Collapse supernovae and the formation of neutron stars and black holes – Principles of the explosion and the possibility of neutrino driven winds. Heavy element formation and the role of the νp-process.


• Cosmic γ-ray emission


• Concept of isomers and nucleosynthetic complications involved in high temperature environments – example of 26mAl


• X-ray bursts – Observations (XMM-Newton and Chandra satellite missions), “Breakout” from hot CNO cycles and nucleosynthetic path of the rp-process; role of waiting points

• Basic overview of nuclear reactions in exploding stars – 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.

• Nuclear reactions leading to solar neutrinos. Concept of neutrino oscillations and analytical formalism of 2-flavour oscillation probabilities.


• Concept of Dark Matter – current experimental studies for direct dark matter detection (LUX-Zepplin and XENON 1T).


• Basic principles of Dark Energy

Assessment pattern

Alternative Assessment

In the event that a student fails the computational group coursework, they will be reassessed with a take home, open book test, consisting of exam style questions.

Assessment Strategy

The proposed assessment strategy for this module will involve:

• 
  30% of group based coursework to produce a final report describing a computational project involving explosive nucleosynthesis yields and/or hydrodynamical stellar simulations, as well as an oral presentation. All students will be marked individually for their contribution to the project based on a peer review process. Open-source numerical codes will be provided. Coursework set in week 6, to be submitted/presented in week 9.
  


• 
  70% for a final, 2 hour closed book examination where students will answer a series of compulsory questions as well as 2 questions from a set of 3 longer questions.
  
   
  

Module aims

• Provide an understanding of the underlying physics behind the formation of stars and stellar evolution.
• Provide an understanding of explosive stellar phenomena, such as novae, supernovae and x-ray bursts, including the underlying nuclear physics processes involved that result in observational data
• 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 and theoretical techniques used in obtaining the key nuclear physics information required.
• Provide an understanding of astroparticle physics, such as neutrino oscillations, dark energy and direct dark matter detection

Learning outcomes

Methods of Teaching / Learning

The learning and teaching methods include:

• lectures and tutorials 

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: PHYM052

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 2023/4 academic year.