The MINOS Light Injection Calibration System
  A description is given of the light-injection calibration system that has been developed for the MINOS long-baseline neutrino oscillation experiment. The system is based upon pulsed blue LEDs monitored by PIN photodiodes. It is designed to measure non-linearities in the PMT gain curves, as well as monitoring any drifts in PMT gain, at the 1% level. 
P. Adamson, J. Alner, B. Anderson, T. Chase, P. J. Dervan, T. Durkin,   E. Falk, P. G. Harris, D. G. Michael, R. Morse, R. N...