%0 Journal Article %T The Magnetic Distortion Calibration System of the LHCb RICH1 Detector %A A. Borgia %A W. Cameron %A A. Contu %A C. D'Ambrosio %A C. Frei %A N. Harnew %A M. John %A G. Lefeuvre %A R. Mountain %A S. Stone %A D. Websdale %A F. Xing %J Physics %D 2012 %I arXiv %R 10.1016/j.nima.2013.08.039 %X The LHCb RICH1 detector uses hybrid photon detectors (HPDs) as its optical sensors. A calibration system has been constructed to provide corrections for distortions that are primarily due to external magnetic fields. We describe here the system design, construction, operation and performance. %U http://arxiv.org/abs/1206.0253v1