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Measuring w a in the New experiment D. Hertzog / June 2004. Plan that rates could be 7 x higher Plan that new WFDs will have deep memory Plan that computer storage is infinite (well, large) Plan that processing is infinite (well, fast).
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Measuring wa in the New experimentD. Hertzog / June 2004 • Plan that rates could be 7 x higher • Plan that new WFDs will have deep memory • Plan that computer storage is infinite (well, large) • Plan that processing is infinite (well, fast) Q method: Energy vs time (integrated WFD samples) T method: Traditional events above threshold, binned Q and T imply different optimizations …. Can we do both with one device and readout scheme? Assert: Yes, we must try, but we may have to have a “favorite” and a “secondary” as details emerge
PbSciFi calorimeter features and faults Features: Resolution good for this application Linear over required range Fast response with scint + PMTs for pileup rejection Dense / compact (fits in tight space, minimizes side-entering electrons) Faults: Mirrored ends imply position-dependent pulse shapes 14 cm high; gap is 18 cm (could use 16 at least) No effective transverse segmentation for spatial pileup segmentation Laser calibration system failed to give better than few tenths of a percent stability
The calorimeters we have are nearly ideal already for the Q method Fibers run radially to 4 PMTs Each tube gets its own WFD Plot E vs time in 20 ns bins You can even save all these records You lose 7% of data’s statistical power compared to normal T method* (run 14% longer) Refs: W. Morse g-2 Note #93 *J. Pretz g-2 Note #326
What calorimeter can handle the T method at 5-7 times the current rate? Maintain 4 ns pulse separation by timing Maintain density (to fit and avoid side e) Segment transversely by about 20 fold How to read it out? What is it made of ? ? Have considered so far PbW crystals – $$, slow SiW sandwich – $$$, R&D, slow? Pb/Scint/Shaslak – long X0 Pb/SciFi rotated – remake blocks, how to read out?