Unit NUCLEAR ASTROPHYSICS

Course
Physics
Study-unit Code
A001724
Location
PERUGIA
Curriculum
Astrofisica e astroparticelle
Teacher
Sara Palmerini
Teachers
  • Sara Palmerini
Hours
  • 42 ore - Sara Palmerini
CFU
6
Course Regulation
Coorte 2022
Offered
2022/23
Learning activities
Affine/integrativa
Area
Attività formative affini o integrative
Academic discipline
FIS/05
Type of study-unit
Opzionale (Optional)
Type of learning activities
Attività formativa monodisciplinare
Language of instruction
Italian
Contents
Stellar physics and physics of the nuclear processes that, in stars, generate energy and modify the composition of the plasma. Physics of the phenomena that induce the restitution of matter modified by nucleosynthesis to the Galaxy, through Supernova explosions or slower stellar winds.
Reference texts
STELLAR EVOLUTION AND NUCLEOSYNTHESIS, S.G. RrYAN AND A.J. NORTON
(Cambridge Univ. Press).
EVOLUZIONE STELLARE, V. CASTELLANI (Sistina edizioni, Roma)
Educational objectives
Provide a detailed knowledge of modern Nuclear Astrophysics
Prerequisites
A good knowledge of classical physics and of the basics of modern physics, as offered by the Bachelor degree in Physics. Very good control of the mathematical tools of calculus.
Teaching methods
Frontal lessons
Learning verification modality
Oral exam
Extended program
1 Introduction on basic concepts Classifications and the HR diagram. Calibration of temperatures. Stellar atmospheres. Radiative transfer. Stellar magnetic activity. Solar wind. Spectroscopy and measurements of abundances. Stellar Populations. Stellar clusters. 2. Stellar physics Probability of states oa a system of particles. Equations of Saha and Boltzmann. Statistics from Maxwell, Bose-Einstein e Fermi-Dirac. Matter at high density: electron degeneracy. Elements of termodynamics with applications to stellar matter. The virial theorem. Equations for the stellar equilibrium. Polytropic solutions. Radiative and convective equilibria, radiation pressure. Equilibrium of degenerate structures. Chandrasekhar's mass. Nuclear interactions in stars. Binding Energy and the distribution of elements. Chemical abundances in the solar system e in other galactic environments. Nuclear reactions and their probability. The Gamow window and the tunnel effect.3. Nuclear Astrophyscis- Cross sections and reaction rates. Various types of reractions in stars: more on the Gamow peak. Rections for the combustion of H in the Sun. Esperiments for measuring cross sections in laboratories: the LUNA experiment. Problems of weak interactions. Neutrinos from the Sun and esperiments for them. Neutrino oscillations. H-burning in advanced stages. He-burning. Fossil radioactivities and the production and survival of 26Al. Radioactive dating. The He flash. Reactions from heavy ions. and the evolutions of massive stars. Neutron-capture processes and their sites.4. Explosive Nucleosynthesis and Big Bang Nucleosynthesis. Cosmological models. Nucleosynthesis in the big bang. The Li problem and the abundance of light nuclei. The Cameron-Fowler mechanism and non-convective mixing. Copsmic rays. The leaky box models. Contributions from the Sun. Spallation in cosmic rays and in solids. Anomalies of Ne e Xe in ancient meteorites. Explosive nucleosynthesis in SNe and novae. Origins of the various SN types. Stellar criteria for dating the Universe.
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