PDTs

1
PDTs
First, the PDT Status

• Readout
• All 6 crates in global run. x39 x34 frequently
  stop due to MFC related Front End errors.
• 85/94 PDTs are in the global runs.
• Infrastructure Electronics during access
• 3 FEBs replaced (MW TM HH)
• HV work on PDT 113/213 to jumper out a broken
  wire until Oct. shutdown. (MW TM)
• Reprogram of BC-layer cobos Completed (HH)

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Timing
Trigger Minbiasticksel 0
OLD Timing Plots
First crossing after synch gap (d.t.550 ns)

• We have made adjustments to move the hits a
  little earlier (reducing t0s).
• T0s are available for All PDTs
• For 67/94 I have measured T0s from timing
  distributions. For the others I made an estimate
  based on the t0s of similar PDTs.
• Three timing sets used so far
• We havent looked at Pads yet - unpacking
  problems.

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PDTs

• Example of T0s from run 130080

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PDT Problem

• Mujet triggers provide sample of relatively clean
  high-pT muons. Sooo where are the tracks?
• I used D0ev to identify the first event (14th in
  the file) that satisfied the mujet trigger. I
  used the save event button to extract it.
• I used dsdump --raw --byteswap to display the
  contents of the event (200000 lines).
• I hand-unpacked and hand event-displayed There
  were nice hits in B C layer PDTs that
  corresponded with the scintillator hits.
• Onne Peters ran the muon code and made an event
  display picture of that event too.

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Unpack Event Display
6
Event Display Picture

• Then
• Onne disabled hit selection and made the event
  display picture again.

7
First Central Muon Track in Run 2 Pbarp Collisons
8
Another Central Muon
9
Hmm
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Hmm2
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Summary/Plans

• Central Muon ID suddenly will achieve higher
  efficiency.
• Short Term proposed plan for muons
• select and tapout dimuon event-tuples
• initially these will be etagt1
• hopefully within a week or so Reco will have a
  fix for central muons, too.
• Use these to study performance and develop W and
  Z to muon object identification
• I believe the events will be primarily b-bbar
  with non-isolated muons until we use isolation.
  Probably we should start where we were in Run I
• delta R (mu-jet) gt 0.7 for 0.5 cone jets
• good idea to check Run I publications
• I recall W/Z and top had slightly different
  criteria

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Conclusions

• We believe PDTs are operating well.
• Starting to put shine on the electronics.
• Kill hot cells
• fix missing channels.
• Weve got t0s for all runs taken since April
  27th and a set of timing parameters which will
  set them to an average of 100 ns.
• We have identified a change in software which
  will make it possible to find tracks in the
  PDTs.
• A quick scan appears to show some electronics has
  been cables backwards.
• Next step hand scan 500 tracks.

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Central Muon during October Shutdown

• Scintillators
• The major task is an SFE cycle to correct a
  time-of-flight gate mistake.
• PDTs
• A-layer access to
• Reprogram timing chips on Cobos
• Replace a couple Cobos and FEBs to suppress hot
  or missing channels
• Rewire FEBlt--gtCobo connections in Oct 1.
• Broken wires
• 10 PDTs have had broken wires jumpered out.
• Procedure to fix the wire involves pumping and
  refilling with operating gas. So we ill need a
  Bob Kubinsky or other expert to assist with that.

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Central Muon during October Shutdown

• PDTs continued
• Survey
• The Run II position of some unsurveyed PDTs is
  known to no better than 1 from Run I data.
  Implication is (Dp)/p 300 instead of 20 in
  those directions.
• Its important to complete the muon survey!

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Central Muon during October Shutdown