New Product: Bergoz CR-BCM

Current Measurement with sub-nanoamperes resolution of CW beams and macropulses.

Based on a prototype developed by S. Srinivasan and P.A. Duperrex at PSI, the CR-BCM is a re-entrant cavity resonator used as a beam current monitor. The CR-BCM operates at the fundamental mode of resonance, i.e. transverse magnetic mode tuned to a given harmonic of the beam repetition rate.

The fundamental mode of resonance is proportional to the beam current or to the bunch charge of single beam pulses. The re-entrant cavity resonator provides a position- and beam-size-independent response. Calibration check is possible without dismounting the cavity from the beam line.

Main Features:

  • Beam repetition frequency from 30 MHz to 175 MHz
  • Response time  < 1 µs
  • 100 mm axial length
  • 300 mm external diameter


  • Cavity systems are known for providing a linear response over a large dynamic range and superior sensitivity compared to commonly used current monitors.
  • The CR-BCM is optimized for applications in charged particle radiation therapy facilities, FLASH experiments, radio-isotope production facilities.


The CR-BCM has fixed outer dimensions for any bunch repetition frequency between 30 MHz and 175 MHz:

  • Axial length: 100 mm
  • External diameter: 300 mm

Visit the CR-BCM page to learn more.