Qweak Qsqrd Tracking

Tracking system Description

The Qweak tracking system is composed of three tracking regions. Region 1 is a GEM based ionization chamber which measures the radial distance of a hit from the beam pipe center and is located 50 cm away from a 20 cm long target. Region 2 is a drift chamber with 6 layers located 1.5 m from target center. A Torous magnet is place centered 2 meters from the target which selects elasticly scattered electrons that pass through a primary collimator just before the magnet. Region 2 is another drift chamber located just in front of the quartz cherenkov detectors. A scintillator appears after the quartz cherenkov detector which is used to trigger the tracking system.

[math]Q^2[/math] for Elastic Scattering

Using only R1 and R2

A plot of the Q^2 error achievable by 2 tracking systems according to the distance Z between the systemad and their combined tracking resolution in mm.