Faraday Collector

The BC75 provides direct readout of proton beam current in the energy range 30 to 250MeV. It is convenient to use and provides absolute accuracy independent of beam energy. Optimal accuracy for protons is in the 100MeV to 250MeV range. Typical beam currents are in the 10pA to 50nA range. Minimum measurable current depends on noise levels and quality of the readout electronics. Measurements of 10pA or less are possible using the IC101 electrometer.

Use of currents as high as 4µA are possible with short periods of exposure. The user must assess the power load and level of activation to set a time limit that is acceptable for their use.


  • Direct measurement of high energy proton beam current
  • Proton energies from 30 to 250 MeV
  • Minimal dependence on beam energy
  • Operates in air - no vacuum system or HV bias required
  • Compatible with IC101, I200, F460, and the F100
  • Based on a proven concept from Bernard Gottschalk developed and used at Harvard Cyclotron Laboratory


  • Particle therapy pencil beam quality assurance
  • Accelerator development
  • Particle therapy system commissioning
  • General high energy ion beam diagnostics