for the observation of the particle beam microstructure

Capacitive pick-up probe with removed front segmented aperture. Inner ring is provided for current pick-up; also seen is the sealing flange with vacuum-sealed Ntype connector and segmented apertures for tuning of impedance.

The capacitive pick-up probe is used for observation of the particle beam micro-structure of RF-accelerators. The probe should be followed by a broadband signal processing system. The pick-up signals may be used to observe the shape of bunches, as well as to measure the position of bunches in time, with reference to a RF-signal. Based on capacitive pick-ups, the following measurements may be performed:

  • Time of flight measurement for determination of particle energy;
  • Longitudinal emittance measurements;
  • Determination of minimum acceleration voltage for RF-structures (phase-scan);
  • Measurement and monitoring of stability of an accelerator with respect to the energy.

By passing the inner electrode, the particle bunch induces a current on the electrode, which is proportional to the time derivation of intensity distribution within the bunch.