1 nigel nation 30 april 2008 more crap nigel nation bu atlas group weekly meeting 29 april 2008
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Nigel Nation 30 April 2008
Morecrap
Nigel Nation
BU ATLAS Group Weekly Meeting 29 April 2008
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Nigel Nation 30 April 2008
Run 33182 (Dec 4 2007) castor/cern.ch/grid/atlas/t0/perm/DAQ/MuonWeekDec07/
169 files (Transfer problem number 50)
TGC sectors 9,10 and 11 were on.
Run Number and Numbers
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EMS1C Residuals
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First pass of raw data uses a Hough Transform to remove spurious hits.
2nd pass uses a scalable least squares algorithm allowing up to 12 tubes hit. This allows for an acceptance angle of 80 degrees perpendicular to
chamber surface (1.3π steradians)
No method to remove δ-rays or outliers
Data stored in structured root file for reprocessing Data file can be opened and viewed with self-
written OpenGL event display.
Method
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Alignment with tracks Currently MOORE does not make tracks between chambers, only
between stations (EM-EI, EM-EO)
Need tracks in adjacent chambers 2D chamber alignment
translations in local chamber coordinates z & y
rotations about x axis
can be done between small and large chambers without TGC information
3D chamber alignment 6 A-line parameter comparison
This needs understanding of TGC 2nd coordinate
Requires alignment of TGCs relative to MDTs
Motivation for Method
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Run 33182 (Dec 4 2007)
TGC
Hough Animation
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Nigel Nation 30 April 2008
Run 33182 (Dec 4 2007) TGC sectors 9,10 and 11 were on.
EMS.1C12 is triggered by TGC
No double pulses seen in TDC spectrum (Andrew Eppig)
Use RAW data files and filter leaving only 6-tube 6-row events
Use Hough Transform to locate tracks Only looking at 6 hits
EMS.1C12 Chamber
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Hough 3D Image
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EMS1C12 Tracks
621967 1484944114230657
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Hough Histograms
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Hough Results
Histogram is being incorrectly filled. As a result the peak is incorrectly found. Currently, top plot (previous slide) bin size is 5 where as bottom is 1.
Second pass of program locates peak from first histogram and expands about its peak. This is why it is failing.
This results in incorrectly found track along with its associated hits
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Nigel Nation 30 April 2008
Tracks
Hough does not pick out correct track
Bins are set incorrectly
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Nigel Nation 30 April 2008
Move to Least Squares Routine
Hough Transform is not working and need to generate track residuals.
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What next?
Modify Hough Transform to get tracks and residuals?
Modify least squares to deal with more that 6 tubes hit?
Intention to be able to look at residuals independently of MOORE. The intention is to compare the two results BOTH the raw hit data and the segments data.
Look at delta-ray production.
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Nigel Nation 30 April 2008
References
http://homepages.inf.ed.ac.uk/amos/hough.html