title: Electron recombination studies of rotationally  cold CH+ ions at the Cryogenic Storage Ring
creator: Paul, Daniel Roman
subject: ddc-530
subject: 530 Physics
description: The present work is concerned with an experimental study of the Dissociative Recombination (DR) process for rotationally cold CH+ ions. Experiments were conducted at the electron cooler of the Cryogenic Storage Ring (CSR) facility, a merged-electron-ion-beams setup. By storing CH+ ions up to 100 s in the T<10 K CSR environment, an ensemble of the lowest three rotational states was produced and time-dependent populations were additionally characterized via photodissociation.    With the methods developed in this work, the DR cross section is obtained in the collision energy range of 0-1.3 eV as a merged-beams rate coefficient and converted into a plasma rate coefficient, which can be used for modeling the chemistry in interstellar clouds. A confinement for the pure J=0 plasma rate is provided for this purpose, resulting from time-dependent measurements on the continually cooling rotational ensemble in CSR.  	  Imaging and arrival time detection of DR fragments are used for characterizing final atomic carbon and hydrogen states and angular fragment distributions. Here, collision energies of 0 meV, 8 meV, 70 meV and 320 meV are investigated. As a result, conclusions about the symmetry of intermediate dissociative states of the CH molecule, participating in the DR reaction, can be drawn.
date: 2021
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/30307/1/DissertationDanielPaul-EPub.pdf
identifier: DOI:10.11588/heidok.00030307
identifier: urn:nbn:de:bsz:16-heidok-303077
identifier:   Paul, Daniel Roman  (2021) Electron recombination studies of rotationally cold CH+ ions at the Cryogenic Storage Ring.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/30307/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng