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Muon Calibration Difficulties. Calibration Shortcomings Angular Effects Old Path Length Correction New Correction Other Matters Results. Ryan Nichol and Chris Smith. Problems With Old Method. Old Calibration Required Double Ended Hits. To Remove Crosstalk. - PowerPoint PPT Presentation
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Muon Calibration DifficultiesCalibration ShortcomingsAngular EffectsOld Path Length CorrectionNew CorrectionOther MattersResults
Ryan Nichol and Chris Smith
Ryan Nichol, Chris Smith
Problems With Old Method
• Old Calibration Required Double Ended Hits.• To Remove Crosstalk.
• Beam Muons Show Even/Odd Asymmetry.
Ryan Nichol, Chris Smith
New Tracker Working Well
Ryan Nichol, Chris Smith
Corner Clippers
New ‘Tracker’ Enabled Lifting Of Double Ended Hit Requirement.
This Led To Inclusion Of More Corner Clipping Muons.
Decided To Remove Corner Clipping Hits From Sample.
Ryan Nichol, Chris Smith
Angular Distribution
Large Angular Asymmetry at CalDet. Due To Orientation of Planes.
Ryan Nichol, Chris Smith
Error On Determination Of Angle
Bands Correspond To Muon Track Length.
Accuracy Limited By Strip Resolution.
Ryan Nichol, Chris Smith
Angular Dependence of Pulse Height
Corner Clippers Removed.
Two Views Have Similar Dependence.
Strange Bimodal Shape.
Ryan Nichol, Chris Smith
Path Length Factors
Angular Dependence. Finite Strip Width.
Affects Two Orientations Differently.
Minimum Path Length In Strip. Path Length In Neighbouring Strips. Transverse Position Across Strip Width. Other Effects??
Ryan Nichol, Chris Smith
Geometrical Constraints
Path Length Constrained By: Finite Strip Width Minimum PL in Strip. Maximum PL in
neighbouring strips.
These extrema are determined by light output.
Ryan Nichol, Chris Smith
Transverse Position Across Strip
Pulse Height Depends on Transverse Position Across Strip.
Ryan Nichol, Chris Smith
Old Path Length Correction
dzdy
dzdy
dzdsZdz
dsY
dzdy
dzdsYZ
ds2
. 22
Tries To Account For: Angle Finite Strip Width Minimum Path Length
Doesn’t Succeed. Introduces Even/Odd
Bias.
Ryan Nichol, Chris Smith
Simulation Results
Simulated Muons In CalDet With Measured Angular Distribution.
Calculated Path Length Differs From True Path Length.
Ryan Nichol, Chris Smith
New Path Length Correction
The ‘Solution’:92%
Only Accounts For Angles.
Corrects to 2% level.
1)1(92.0 dzdsds
Ryan Nichol, Chris Smith
Results
New Calibration Removes Some Of The Even Odd Asymmetry
•Still not an ideal calibration.
Ryan Nichol, Chris Smith
Forwards-Backwards Asymmetry
Seemingly More Energy Deposited By Cosmics Traveling Backwards Through The Detector. Steel-Scintillator-Air or
Steel-Air-Scintillator? Groove Position?
Needs Further MC Investigation.
Ryan Nichol, Chris Smith
More Front-Back Fun
Ryan Nichol, Chris Smith
Summary
Large Angular Asymmetry Between Views. Due To Orientation Of Planes.
Complicated Pulse Height Dependence.Old (Current) Path Length Correction
Wrong.Best Results From A ‘Fudge Factor’
