Threshold Tuning of the ATLAS Pixel Detector

The threshold of each pixel in the Pixel Detector must be properly set in order to optimize position resolution and particle detection efficiency. This note details the threshold tuning performed for the full pixel detector over a 4-month period in the fall of 2008. At the end of this period, 94% of the detector was tuned to a mean threshold value of 3939 e, which is offset from the true threshold value by ~60 e,with an RMS of 37 e. The remaining 6% of the detector was not measurable due to software or hardware problems.