1 / 9

The VDS performance

The VDS performance. Outline: Current reconstruction / analysis Alignment Efficiencies Monte Carlo Masking Usability of runs Time stability New / on raw data visible: The single event killing Occupancy problems Occupancy maps on single event level Summary.

martha-horn
Download Presentation

The VDS performance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The VDS performance • Outline: • Current reconstruction / analysis • Alignment • Efficiencies • Monte Carlo • Masking • Usability of runs • Time stability • New / on raw data visible: • The single event killing • Occupancy problems • Occupancy maps on single event level • Summary

  2. Alignment, Efficiencies • Alignment: • Done for all periods with hardware changes • Alignment was done synchronised and coordinated for all subdetectors • Produced sets: • 9 for pre-November-runs • 7 for the data taking period • 4 test files: VDS primaries & secondaries agree in data and MC ! • Analysis shows: We have to align the VDS more often. • Efficiencies : • In C&A for 30 cases, ready to use • Based on repro3 /repro0 • Done per plane • Variations due to hardware changes seen • Unmounted channals seen 2 sets of masks: 21249 (open) 20243 (black)

  3. Masking, Usability of runs, Time stability • We do not have a masking finer than 1 plane yet operational • Due to hardware problems we have an incomplete list of 4..? Runs where the VDS was not well usable • Investigations of time stability just started • MC / data comparison shows some problems • Time stabilty is beeing • investigated ! R. Wolf, dipl. thesis Age: 20h ! + 4 planes unstable ! Dez. min bias runs

  4. The single event killing and beyond.. • From March meeting: • There was a dynamical, unmonitored occupancy-cut applied in all data • Unknown effect on data. We may have more ‚surprises‘ on tape, and just be blind to them ! • => some parts of your (single) event may be invisible (up to 39 helixes ‚flushed‘) • => Call it: „Jet supressor“, „generation of missing energy or pt“ • No way to recover in ‚mini‘ • Relaxing this reveals a ‚new‘ problem: (but seen by SLT) • Occupancies get crazy (SLT confirms) • There are too many wrong-sign • clusters • We can cut but need • to understand • Might even be usefull • => Test by Friday !

  5. Fine Masks Provide bad channal masks, get rid of „gute Seiten, schlechte Seiten“ =>Single strip cuts are developed and ready for ARTE ! these are found easily ! New technique.. .. new surprises: part-time bad HELIXES are good but some chans are bad (always) these are never OK, but cause sometimes trouble == bad efficiency for the plane or a bad HELIX! Simply: unmounted !

  6. Masking Channals, Summary First shot might be x2 too strict, Wait till June 1st ! • Alignment will become much easier • The masks quite are stable (single chans !) • Consequences on resolution and efficiency ? • Tests will take place this week !

  7. Time stability Micha • Time-stability for MB-analysis: • Might be Okay • The new findings suggest an even better system • ‚Helixes in time‘ might be a small problem

  8. From the year 2000 • Primary position drifting in run: 4µm/h ! • 200 µm observed in this season. • The drift can not be corrected with alignment • The IP / beam / target relation is untested • Checks will come (June)

  9. Summary • For the current analysis, we have • Efficiencies • Alignment (C&A tables for all important time periods existing, not too fine) • MC masks (using C&A, ready to use) • Per run investigations just started • Some problems found & attacked • Unknown systematics due to the ´single event-killer´ => dangerous? • Single strip hit maps show that problematic chans stay stable over time • Some ‚interesting‘, new problmes found • Number of hits in (1..10)% of the events looks crazy • Countermeasure for this found => will be tested with physics soon • Alignment procedure (showstopper was DQ ´by hand´) will improve further • Suggested a procedure for a new repro • We can improve the current situation quite a bit !

More Related