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| photograph 98/12/5 | photograph 99/1/21 |
The B-Factory project at KEK is now getting
into final tuning stage of the e+/e- asymmetric
collider (KEKB) and of the detector (BELLE)
towards the starting of the experiment in
April, 1999. Construction of the BELLE detector
was completed on 18-Dec-1998 after the 3
year's construction work. The detector components
have been tested and finally the detector
started full operation with the solenoid
magnetic field of 15,000 Gauss on 18-Jan-1999.
The cosmic-ray run started with its on-line
data acquisition system. Millions of cosmic-ray
events have been accumulated already and
they have been used for calibration of the
detector components.
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| photograph 98/12/5 | photograph 99/1/21 |
The photographs show the BELLE detector during the assembly stage (12/15) and after completion of assembly(1/21). In the assembly photos, one can see the complexity of the detector components and cables inside. When it is in full operation with solenoid magnet ON, one can not see the inside structure because the endcap yokes are attached.
The figures below are the event display of
cosmic-ray track observed by the BELLE detector.
The data have been analyzed and the detector
signals were reproduced by the computer.
The left side figure shows the whole detector,
where cosmic ray went through 6 type of detector
components (Muon detector, CsI calorimeter,
Time-of-Flight counters, Aerogel Cerenkov
counters, Central Drift Chamber (CDC) and
Silicon Vertex Detector (SVD) ) and produced
the signals. The track was bent due to the
detector magnetic field. The right side figure
shows the innermost SVD region, where CDC
signals and SVD signals line up. The SVD
will achieve the position measurement accuracy
of a few tens of micrometers.
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[Related URL]
www-admin@kek.jp Jan 26, 1999