Speaker
Mr
Kai-Yi Kao
(National Taiwan University (TW))
Description
The Preshower detector, as part of the CMS endcap electromagnetic calorimeter, is designed to have good spatial resolution to identify the position of incoming photons/electrons in the endcaps. It is based on 4288 silicon sensors, each with active area 61x61 mm^2 segmented into 32 strips with 1.9mm pitch. Its spatial resolution relies upon excellent alignment with the neighbouring detectors, especially the Tracker. This is based on the extrapolation of tracks from the Tracker to the Preshower and gives an alignment precision of a few millimeters for translation and a few milliradians for rotation. The method for Preshower alignment will be discussed and the results of the alignment with respect to the Tracker will be presented.
Author
Mr
Kai-Yi Kao
(National Taiwan University (TW))