Introduction

This package is designed as on offline monitor to demonstrate/verify proper functioning of SCT modules by tracking particles through the detector and comparing the hits found to those predicted. The hit efficiency is measured on a per module level, for both the barrel and endcap regions.

The code is designed to be versatile enough to be used for commisioning and long term running of the detector.

Be able to read and write results to database

Method

For a given module: Eff = #hits Observed / #Hits Expected

Numerator:

A simple map of all hits associated with the reconstructed tracks Plot is for 2nd barrel layer

Denominator:

For a given track intersecting a given layer/disk:

• Remove hits (if present) from ith disk and refit track(using xkalman)
• Extrapolate refitted track to ith disk and find intersection point(Using TrkExtrapolation)
• Predict a hit should have been found at this point

This prediction becomes the denominator

1-efficiency plots

In this example, I have introduced some inefficiencies: one chip on side 0 (128 strips) have been turned off in the phi=15 modules. Theoretically they should have an inefficiency of 8% Some 100% efficient modules have been measured as being ~2% inefficient

Strip Detail

For any module with an efficiency less than x (value set by user), strip detail is recorded. X=95% in these examples. Can look at Strip map to look for cause of inefficiency

-- HelenHayward - 27 Mar 2006