The Monochromator Controller (MoCo) is an electronic module designed to regulate the position of an optical component in a synchrotron radiation beamline. The controller corrects the position of the component, typically a mirror or a monochromator, by monitoring the outgoing beam and actively compensating low frequency drifts due to thermal load changes or mechanical instability.



  • Active regulation of an optical element on one of its degrees of freedom.

  • Keeps constant either the transmission or the position of the beam.

  • Primarily designed for double crystal monochromators but it could be potentially used with other optics (mirrors, single crystal monochromators).

  • Main features:- Time constant from 1 ms to 1 minute- Automatic tuning- Autorange- Beam lost detection- Current and voltage inputs- Serial line communication

  • Can be configured from slave mode to fully automatic mode.

  • Built-in current amplifiers (24 gain ranges over 7 decades).