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@PHDTHESIS{Rink:211856,
      author       = {Rink, Ann-Kathrin},
      title        = {{M}ass and {L}ife-{T}ime {M}easurement of the 1.7 {MS}
                      $^{215}${P}o {I}sotope {A} {C}rucial {T}est of the {N}ovel
                      {C}oncept of the {C}ryogenic {I}on {C}atcher for the
                      {S}uper-{FRS} at {GSI}-{FAIR}},
      school       = {Justus-Liebig Universität Gießen},
      type         = {Dissertation},
      reportid     = {GSI-2018-00736},
      pages        = {111},
      year         = {2017},
      note         = {Dissertation, Justus-Liebig Universität Gießen, 2017},
      abstract     = {In modern nuclear- and nuclear astrophysics exotic nuclei
                      are central research topics. Especially close to the
                      driplines these nuclei show novel and unexpected properties
                      compared to the well known stable isotopes. The obtained
                      information from these nuclei can explore the knowledge of
                      stellar nucleosynthesis.The international Facility for
                      Anti-proton and Ion Research (FAIR-GSI) has the probability
                      to provide important contributions using the Super Fragment
                      Separator (Super-FRS). Novel experimental concepts for
                      measurements with short-lived nuclei are presented in this
                      thesis together with pilot experiments performed at the
                      current Fragment Separator FRS at GSI.In the context of this
                      doctoral thesis a method to measure very short-lived nuclei
                      has been successfully developed. Therefore projectile
                      fragments have been produced, separated in-flight and
                      thermalised in a cryogenic gas-filled stopping cell. After a
                      fast extraction the stopped projectile fragments are
                      investigated with a high resol- ution mass spectrometer. The
                      ion’s kinetic energy is in the order of several eV for the
                      transport through an RFQ beam line (10−2 mbar) and maximal
                      1.3 keV in the analyser of the mass spectrometer. To reduce
                      the phase space of the ions, they are either He- or N2-gas
                      cooled.The efficient stopping of a separated exotic ion
                      beam, produced of a 1000 MeV/u 238U projectiles, is
                      challenging due to their large range distribution. Even
                      though a mono-energetic degrader system reduces the range
                      distributions, they are still bigger than the current areal
                      gas density of the cryogenic stopping cell (CSC). An
                      important goal for future experiments is a higher areal
                      density to achieve the complete and thus efficient stopping
                      of the interesting nuclei.Effects like space charge or
                      enlarged extraction and transport times have to be minimized
                      because they are limiting the system’s performance. If
                      space charge is built up inside the buffer gas, the
                      electrical transport field will be attenuated and a decrease
                      in efficiency will be the result.In this work, extraction
                      times of 2 ms have been achieved using a different geometry
                      of the CSC. Important parameter dependencies on gas pressure
                      and electrical fields have been tested with success for the
                      next generation CSC that will be built for the Super-FRS at
                      FAIR.The current CSC shows extraction with full efficiency
                      up to 3 × 1011 He3+ ions produced by the incoming
                      fragments, which corresponds an energy loss equivalent of
                      104 221Ac ions. Higher beam rates cause a drop in extraction
                      efficiencies. The future CSC will provide more than three
                      orders of magnitude higher rate capability as the current
                      system, which enables experiments with even higher
                      background rates. The obtained results now pave the way for
                      the technical realization of the next generation Ion Catcher
                      for the Super-FRS.Furthermore, a new concept has been
                      developed to perform accurate mass and life-time
                      measurements of the 215Po isotope. The measurements have
                      been per- formed under conditions which are foreseen for the
                      Low-Energy Branch of the Super- FRS [Dickel et al., 2015b].
                      It has been the first direct mass measurement of the 215Po
                      isotope, even though the mass value is well known due to
                      α-spectroscopy and system- atics. The obtained mass value
                      of the 215Po isotope is (214.9993276 ± 8.07 · 10−05) u,
                      which is in agreement with the literature value given by
                      (214.9994201±2.7×10−6) u.The result of the MR-TOF-MS
                      assisted decay spectroscopy of 215Po performed in course of
                      this work is (1.7735 ± 0.055) ms. MR-TOF assisting decay
                      spectroscopy simplifies the spectroscopy measurement by mass
                      identification and separation. It also denotes that there
                      will be no other decay channels but 215Po and its daughter
                      decays to populate the 215Po decay channel
                      undesirably.Concluding the experimental and simulated
                      results evince that the new concepts for experiments at the
                      Super-FRS are based on solid principles. A completely new
                      generation of accurate measurements of rare isotopes are
                      enabled.},
      cin          = {FRS / SuperFRS-EC@FAIR},
      cid          = {I:(DE-Ds200)FRS-20110310OR124 /
                      I:(DE-Ds200)Coll-FAIR-SuperFRS-EC},
      pnm          = {612 - Cosmic Matter in the Laboratory (POF3-612)},
      pid          = {G:(DE-HGF)POF3-612},
      experiment   = {EXP:(DE-Ds200)Altdaten-20200803},
      typ          = {PUB:(DE-HGF)11},
      urn          = {urn:nbn:de:hebis:26-opus-131139},
      url          = {https://repository.gsi.de/record/211856},
}