title: Charge-exchange studies of bare and hydrogen-like low-Z ions in the X-ray and extreme-ultraviolet ranges inside an electron beam ion trap
creator: Dobrodey, Stepan
subject: 530
subject: 530 Physics
description: In this work, a cryogenic electron beam ion trap (EBIT) for charge breeding of rare, short-lived isotopes at the ARIEL facility at TRIUMF was designed and assembled for future investigations of astrophysical processes. It was characterized at a maximum electron-beam current of 1 A. Furthermore, charge-exchange (CX) processes, which are relevant for the interface between hot plasmas and cold gases in astrophysical environments, were extensively studied. In these experiments, hydrogen-like and bare sulfur, argon, and oxygen ions capturing electrons from various neutral gas targets into highly-excited states with subsequent radiative relaxation via emission of X-rays were investigated. Thereby, a possible explanation for the recently observed emission line at 3.5 keV in galaxy  clusters, with a proposed origin in the decay of sterile neutrinos, was given, in the form of CX induced K-shell emission from hydrogen-like sulfur. Additionally, measurements of extreme-ultraviolet L-shell transitions following CX into highly ionized oxygen in the range between 8 nm and 20 nm, utilizing a grating spectrometer, is presented. The results are compared with different CX models, mainly based on the multichannel Landau-Zener approach. Significant discrepancies between various experiments and models, as well as the models among each other, were ascertained and are extensively discussed.
date: 2019
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/27344/1/Dobrodey_PhD_Final.pdf
identifier: DOI:10.11588/heidok.00027344
identifier: urn:nbn:de:bsz:16-heidok-273444
identifier:   Dobrodey, Stepan  (2019) Charge-exchange studies of bare and hydrogen-like low-Z ions in the X-ray and extreme-ultraviolet ranges inside an electron beam ion trap.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/27344/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng