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The Sept 2005 CLAS Region 1 DC Repairs

The September 2005 CLAS Region 1 DC Repairs

The CLAS (CEBAF Large Acceptance Spectrometer), located in Experimental
Hall B at TJNAF (Thomas Jefferson National Accelerator Facility), consists
of 18 individual wire chamber detectors. Each of these detectors contains
more than 10,000 individual wires and associated electronics. Repairs are
required to remove broken wires and to remove or replace shorted preamps

Region 1 Repairs

This was the first time the R1 detector assembly was removed from the torus
for repairs since commissioning. There were 2 areas of 160 channels that were
not functioning due to a shorted pre-amp. Since all 160 pre-amps or SIPs are
connected in parrallel, indivivdual pre-amps were removed until the short went away.
Replacement SIPs were then soldered in place.











































































Final Results and Monitor Plots

BEFORE AND AFTER MONITOR PLOTS

Region 1 Sectors 1, 2, and 3 in the above mon plot show the repaired DCLV hole, 160 channels recovered.

Region 1 Sectors 4, 5, and 6 in the above mon plot show the repaired DCLV hole, 160 channels recovered.
There is a new HV hole in S4 Axial, layers 11 and 12. This seems to be an open circuit on the HV board.

CLAS DC Fabrication, Installation, and Repair Page Links

Experimental Hall B links

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THIS PAGE WILL ALWAYS BE UNDER CONSTRUCTION 10-13-05