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Muon Calibration Difficulties. Calibration Shortcomings Angular Dependence Old Path Length Correction New Correction Results. Problems With Old Method. Old Calibration Required Double Ended Hits Beam Muons Show Even/Odd Asymmetry. Angular Distribution. Large Angular Asymmetry at CalDet.
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Muon Calibration Difficulties Calibration Shortcomings Angular Dependence Old Path Length Correction New Correction Results
Problems With Old Method • Old Calibration Required Double Ended Hits • Beam Muons Show Even/Odd Asymmetry Ryan Nichol, Chris Smith
Angular Distribution • Large Angular Asymmetry at CalDet. • Due To Orientation of Planes. 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
Old Path Length Correction • 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. Ryan Nichol, Chris Smith
Results • New Calibration Removes Some Of The Even Odd Asymmetry • Still not an ideal calibration. 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’ 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
New Tracker Working Well Ryan Nichol, Chris Smith
Transverse Position Across Strip • Pulse Height Depends on Transverse Position Across Strip. Ryan Nichol, Chris Smith
Error On Determination Of Angle • Bands Correspond To Muon Track Length. • Accuracy Limited By Strip Resolution. 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