An active interlock system for the LNLS X-ray ring insertion devices

A description is given of the design and operation of an active interlock system which has been installed in the NSLS (US National Synchrotron Light Source) X-ray electron storage ring to protect the vacuum chamber from thermal damage by missteered high-power photon beams from insertion devices (IDs). The system employs active beam position detectors to monitor beam motion in the 1D straight sections and solid-state logic circuitry to dump the stored beam in the event of a fault condition by interrupting the RF. To ensure a high degree of reliability, redundancy and continuous automatic checking have been incorporated into the design. Overall system integrity is checked periodically with the beam at safe levels of beam current.<>