Speaker
Description
The TOP detector of the Belle II Experiment at KEK is a particle
identification detector, devoted mainly to the separation of charged pions
and kaons.
Principle of operation of the TOP is the total internal reflection of
Cherenkov photons emitted by charged particles while crossing a quartz
radiator. The Cherenkov photons are then detected by an array of micro-cannel plate
photomultipliers, The position and time of arrival of the photoelectrons,
are used to reconstruct simultaneously both the
Cherenkov angle and the time of flight from the interaction vertex to the
detector.
In order to achieve a time resolution of less than 100 ps , necessary to
separate kaons from pions, the performance of electronics and PMTs must be continuously monitored by a high resolution laser calibration system.
This talk reports about the design, characterization, construction and
installation of this light distribution system
consisting of a picosecond laser source, a printed light circuit (PLC),
long single mode fibers coupled to bundles of multimode fibers terminated with graded
index microlenses, to provide illumination of all the PMT pixels with very small
time jitter (less than 50 ps).
| Registered | Yes |
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Primary author
External references
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