Coherent Effects and Impedance (CEI)


​​​​​The Coherent Effects and Impedance (CEI) section provides expertise in the field of impedance computation and optimization, and multi-particle (collective) effects to study the coherent effects. The section is responsible for:

  • Studies of the coherent effects limiting the performance of the present and future CERN accelerators (e.g. beam coupling impedance, space charge, beam-beam and electron cloud ) and of their mitigation
  • Theoretical, simulation and experimental research in the dynamics of high-intensity and/or high-brightness hadron beams
  • Impedance and beam-induced RF heating computations, measurements and follow-up
  • Development and maintenance of software tools to study coherent multi-particle beam dynamics (e.g. PyHEADTAIL, PyECLOUD, etc.)
  • Optics database, aperture models, and aperture checks for the PS and SPS complex.​

The section contribut​es to machine coordination and beam physics support for commissioning and operation (e.g., parameter definition, strategy, measurement procedures) of CERN hadron synchrotrons. The section hosts the co-ordination of the machine studies of LHC injectors’ complex and of the LHC Injectors’ Upgrade (Deputy Project Leader).​ 

Summary of impedance models of the CERN machines: