Muon Calibration DifficultiesCalibration ShortcomingsAngular DependenceOld Path Length CorrectionNew CorrectionResults

Ryan Nichol, Chris Smith

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

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

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.