Laserwire Diagnostics: From Electrons to Negative Hydrogen Ions

Konstantin Kruchinin

Research output: ThesisDoctoral Thesis

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Transverse particle beam diagnostics is crucial for stable and reliable operation of the future accelerators. In some cases, conventional invasive methods for measuring the beam parameters cannot be applied. In these cases, new non invasive methods are required. The state-of-the art in non-invasive transverse diagnostic is based on laserwire technology where by scanning the focused laser beam across the beam of particles and measuring the flux of the secondary particles produced in laserwire interaction one can determine the particle beam parameters. This thesis describes the implementation of the laserwire technology in two different cases. The first one is the development of the laserwire beam profile monitor at the Accelerator Test Facility 2 (ATF2) in KEK, Japan for measuring the transverse profiles of very small electron beam which is required for future electron-positron colliders such as Compact Linear Collider and International Linear Collider. Resent results, showing achievement of sub-micrometre resolution are presented. In conjunction to laserwire, a supplementary beam profile monitor based on optical transition radiation was developed and implemented. The recent results of measuring the electron beam profile and emittance are presented. The second one is the demonstration of low power, fibre coupled laserwire emittance scanner for measuring the transverse phase-space parameters of the high intensity beam of negative hydrogen ions at LINAC4 in CERN, Switzerland. The new LINAC4 will accelerate H− ions to 160 MeV and ultimately replace the existing 50 MeV LINAC2 in the injector chain for the Large Hadron Collider upgrade. Recent results obtained at 3 MeV commissioning stage are presented. Finally the thesis discusses the future plans and prospects including improvements of the laserwire system for future electron linear colliders and development of the new combined optical transition/diffraction radiation station at ATF2 for measuring the electron beam emittance and profile with 100 nm resolution. Future plans toward the final design of the laserwire station for 160 MeV H− beam at LINAC4 and 12 MeV beam at the Front End Test Stand (FETS) in Rutherford Appleton Laboratory are discussed.
Original languageEnglish
Awarding Institution
  • Royal Holloway, University of London
  • Karataev, Pavel, Supervisor
Award date1 Aug 2015
Publication statusUnpublished - 2015

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