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@MASTERSTHESIS{Niedermayer:893103,
      author       = {Niedermayer, Philipp},
      othercontributors = {Lehrach, Andreas and Breitkreutz, Bernd},
      title        = {{D}evelopment of a {F}ast {B}etatron {T}une and
                      {C}hromaticity {M}easurement {S}ystem {U}sing
                      {B}unch-by-{B}unch {P}osition {M}onitoring},
      school       = {RWTH Aachen},
      type         = {Masterarbeit},
      reportid     = {FZJ-2021-02561},
      pages        = {92},
      year         = {2021},
      note         = {Masterarbeit, RWTH Aachen, 2021},
      abstract     = {The betatron tune and its dependence on the momentum
                      (chromaticity) are essentialquantities of circular particle
                      accelerators. The tune must be monitored in order toavoid
                      optical resonances which cause instabilities and limit the
                      lifetime of the storedparticle beam. Control of the tune and
                      chromaticity are also required to achieve longcoherence
                      times in spin polarization experiments as carried out by the
                      JEDI collaboration.In the scope of the present thesis, a
                      fast betatron tune and chromaticity measurementsystem is
                      developed for the Cooler Synchrotron COSY. The betatron
                      oscillations ofthe beam are excited through stripline
                      electrodes with a white noise RF signal in anappropriate
                      frequency band. Resonant transverse oscillations are then
                      observed usingcapacitive beam position monitors.
                      Characteristic for the newly developed system isthe
                      determination of the betatron tune from bunch-by-bunch beam
                      position measurements.This allows for time-discrete tune
                      measurements within a few milliseconds aswell as continuous
                      tune monitoring – for example during the acceleration
                      ramp.The high precision tune measurement also enables
                      determination of the beam chromaticity.Therefore, the beam
                      momentum is varied by means of RF frequency sweepsand the
                      subsequent tune change is measured. For routine use during
                      beam operationand experiments, the developed method is
                      integrated into the control system.Finally, measurements
                      showing the operational capabilities and limits of the
                      methodare presented. The influence of different parameters
                      on the signal strength is analysed.For commissioning,
                      control of the betatron tune and compensation of the
                      chromaticityare demonstrated.},
      cin          = {IKP-4},
      cid          = {I:(DE-Juel1)IKP-4-20111104},
      pnm          = {621 - Accelerator Research and Development (POF4-621)},
      pid          = {G:(DE-HGF)POF4-621},
      typ          = {PUB:(DE-HGF)19},
      url          = {https://juser.fz-juelich.de/record/893103},
}