Nuclear Astrophysics

The module covers the physics of stellar structure, hydrostatic equilibrium, thermodynamics of the stellar interior, thermonuclear reaction rates, and how nuclear energy production is coupled to the physical structure of hydrostatic stars. The nuclear energy production is the result of thermonuclear reactions and their rates; the students will learn what nuclear reaction rates are and the nuclear physics principles which govern the rates. Furthermore, the lecture covers the nuclear physics and astrophysics of explosive stellar phenomena (nova, x-ray bursts, supernova). The nucleosynthesis production mechanisms of the s-process, r-process and rp-process will be taught, and their astrophysical sites will be understood. Lectures will also cover topics in experimental methods in nuclear astrophysics, such as the measurement of thermonuclear reaction rates, lifetimes of excited nuclear states, high precision nuclear mass measurements, and indirect nuclear measurements of nuclear reaction rates. Additionally, special topics concerning the past interaction of supernova explosions and Earth will be presented. At this point, the student will have learned where the elements beyond iron are produced in our Universe, the known sites of where the elements are made, and the nuclear physics processes responsible for their production

After successful completion of this module, the student should be able to

• Know the astrophysical sites for the production of elements origin of the elements from carbon to iron, and the associated hydrostatic burning phases of these sites.
• Know what a thermonuclear reaction rate is, and the inverse photo-disintegration reaction rate.
• Know what a resonate reaction rate is, and how it compares to reaction rates that proceed through pure quantum tunneling.
• Identify the nuclear production processes in our universe that form the elements beyond iron.
• Know about some experimental methods used for measuring nuclear reaction rates.
• Understand the relative timescales involved in explosive stellar phenomena, and how nucleosynthesis is affected by the relative time scales of the reaction rates versus the timescale of the explosion.
• Understand the physical principles of the hydrostatic structure of stars and how the nuclear energy production within them affects their structure.

No preconditions in addition to the requirements for the Master’s program in Physics.

The topics of this module are covered through a lecture format in which the students are expected to be interactively engaged in answering rhetorical questions (at times) from the professor, in order to ensure their understanding of the presented material and derivations. The topics are covered with mathematical rigor; the theoretical results are derived entirely, or sufficiently such that the students can derive final results from what is presented in the lecture scripts in combination with explanations discussed in the lecture.

Exercise classes are available and are either covered by an advanced doctoral student or by the professor. The exercise assignments are voluntary; however, students are highly encouraged to do them in order to further their understanding of topics covered in the lectures. The exercise class format is that students are to come having already attempted the problems in the assignments; those will then be the problems covered and discussed in the exercise classes.

Lectures are presented using PowerPoint rather than white/chalkboard. The PowerPoint scripts are also printed out and delivered to the students so that they have the opportunity to “mark up” their scripts during the course of the lecture. Scripts and exercise assignments are also available online in PDF format. In exercise classes, white/chalkboards are used in the course of answering questions.

• C.E. Rolfs & W.S. Rodney: Cauldrons in the Cosmos: Nuclear Astrophysics, University Of Chicago Press, (2005)
• D.D. Clayton: Principles of Stellar Evolution and Nucleosynthesis, University Of Chicago Press, (1984)
• C. Iliadis: Nuclear Physics of Stars, Wiley-VCH, (2007)
• B.E.J. Pagel: Nucleosynthesis and Chemical Evolution of Galaxies, Cambridge University Press, (2009)
• D. Arnett: Supernovae and Nucleosynthesis, Princeton University Press, (1996)
• B.W. Carroll & D.A. Ostlie: An Introduction to Modern Astrophysics, Pearson, (2006)
• G. Faure & T.M. Mensing: Isotopes: Principles and Applications, Johen Wiley & Sons, (2004)

There will be an oral exam of 45 minutes duration. Therein the achievement of the competencies given in section learning outcome is tested exemplarily at least to the given cognition level using comprehension questions and sample calculations.

For example an assignment in the exam might be:

• What is the Gamow window?
• What is a waiting-point nucleus?
• What are the dominant abundances of CNO-cycle burning, and why?

Participation in the exercise classes is strongly recommended since the exercises prepare for the problems of the exam and rehearse the specific competencies.