Scintillating fiber trackers with optoelectronic readout for the CHORUS neutrino experiment

The nature of neutrino mass and the phenomenon of neutrino oscillations

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The CHORUS scintillating fiber tracker and its monitoring systems

“…The CHORUS tracker system [9] expands its application by more than an order of magnitude. It is based on a total of about 1.2 million plastic scintillating bers of 500 m diameter and 2.3 m length (comprising 1.6 m of useful detector element and 0.7 m of exible light guide).…”

The trigger system of the CHORUS experiment

“…The pulse height of the PMT signals is measured by 8 channel, 12 bit ADCs 3 , which can store 16 events with a digitisation time of 16 s. Eight PMTs are grouped into one ADC channel with linear mixers 4 . The charge is integrated within a 150 ns gate.…”

“…1182. 4 Commercial NIM analog mixers and mixers specially designed at NIKHEF. 5 \Calibrating and gain monitoring of the CHORUS PM's", NIKHEF/CHORUS internal note (1994); http://choruswww.cern.ch/online/online.html 6 Lecroy Research Systems, VME TDC Model No.…”

“…In each 14.4 s cycle of the SPS there are two spills of 6 ms, separated by 2.7 s. The main diculties facing the trigger system are related to the need to form a strobe (i.e. a timing signal to synchronise logic decisions), since there is no incoming charged particle, and the limit of two events perneutrino spill, imposed by the opto-electronic system used to read-out the scintillating bre tracker [4].…”