Nukleosinteza elemenata težih od željeza

master's thesis

• Title (english): Nucleosynthesis of elements heavier than iron
• Author: Roman Divjak
• Mentor: Nils Paar (mentor)
• Committee member: Nils Paar (predsjednik povjerenstva)
• Committee member: Matko Milin (član povjerenstva)
• Committee member: Maja Planinić (član povjerenstva)
• Committee member: Tomislav Marketin (član povjerenstva)
• Committee member: Mirko Planinić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2017-02-27, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Nukleosinteza elemenata počinje od najranijeg doba svemira, svega nekoliko sekundi nakon Velikog Praska kada nastaju prvi elementi i prve jezgre u svemiru. Nakon formiranja zvijezda započinju procesi u njihovoj unutrašnjosti čime započinje nova faza sinteze elemenata. Proučavajući evoluciju zvijezda i nuklearne reakcije koje se odvijaju u njihovom okruženju možemo objasniti zašto je raspodjela elemenata u svemiru takva kakva jest, zašto nekih elemenata ima više od drugih. Supernove su posebno zanimljive u tom aspektu jer upravo tijekom tih događaja nastaje značajan broj elemenata koji su teži od željeza, no otkriveno je još područja gdje raznim procesima nastaju takvi elementi. Teorija nastanka elemenata težih od željeza svodi se na četiri glavna procesa: s-proces, r-proces (uhvat neutrona), p-proces i rp-proces (uhvat protona). Naše razumijevanje tih procesa se još uvijek razvija i ima još mnogo otvorenih pitanja i nepoznanica na koje treba dati odgovor. Osnovni cilj ovog rada je istražiti i pojasniti način i mjesto nastanka elemenata težih od željeza, te naposljetku zašto je raspodjela elemenata u svemiru baš takva kakva jest.

Abstract (english)

Nucleosynthesis starts from the earliest time of the universe, a few seconds after the Big Bang when the first elements and nuclei were created. After the star formation new processes began in their interior, starting a new phase of the nucleosynthesis. By studying evolution of stars and nuclear reactions which take place in their surroundings, we can explain why element abundances are distributed in accordance to observations, why are some elements more abundant than the others. Supernovas are especially interesting site for the synthesis of elements heavier than iron, but other astrophysical scenarios have also been discovered where such elements are created in some processes. Theory which describes how the elements heavier than iron are produced is based on four key processes: s-process, r-process (neutron capture), p-process and rp-process (proton capture). Our understanding of those processes is still evolving and there are still many open questions. The primary goal of this thesis is to explore and explain the ways how and places where the elements heavier than iron are synthesized, and to explain the structure of observed element abundances.

• Keywords: nukleosinteza; fuzija; fisija; evolucija zvijezda; supernova; energija vezanja po nukleonu; magični brojevi; beta raspad; alfa raspad; uhvat neutrona; uhvat protona; s-proces; r-proces; p-proces; rp-proces
• Keywords (english): nucleosynthesis; fusion; fission; stellar evolution; supernova; binding energy; magic numbers; beta decay; alpha decay; neutron capture; proton capture; s-process; r-process; p-process; rp-process
• Language: croatian
• URN:NBN: urn:nbn:hr:217:921704
• Study programme: Title: Physics; specializations in: Education; Course: Education; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra edukacije fizike (magistar/magistra edukacije fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2017-06-13 15:18:31