非表示:
キーワード:
-
要旨:
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.
