UBC Theses and Dissertations
K2K near detector laserball calibration : manipulator motivation, design and results Berghaus, Frank Olaf
The K2K experiment uses a muon neutrino (v[sub μ]) beam generated at the KEK accelerator facility, aimed at Super-Kamiokande (Super-K) detector 250 km away, to measure v[sub μ] oscillations first seen from atmospheric v's at Super-K. The measurement is done using two detectors. The near detector measures the v[sub μ] flux 300 m from the origin of the neutrino beam. The far detector (Super-K) measures the neutrino flux 250 km downstream. One main source of error in the oscillation measurement is the understanding of the near detector. After some optical calibrations along the vertical axis of the One Kilo Ton (1KT) detector found problems with the position reconstruction a manipulation system was built. The goal of this manipulation system was to allow exploration of the entire 1KT volume with a calibration source. The design required the manipulation system to place the calibration source to ~1 cm accuracy in the 1KT, and to avoid all contact with the photomultiplier tubes monitoring the tank volume. This manipulation system was built and tested at TRIUMF (Tri-University Meson Facility) and deployed in the 1KT detector at KEK. The results of the optical position reconstruction indicate a reconstruction bias of unknown origin at high occupancy.
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