ATLAS SCT POWER SUPPLY SYSTEM

Abstract

The ATLAS SCT (semiconductor tracker) comprises 2112 barrel modules mounted on four concentric barrels of length 1.5m and up to 1m diameter, and 1976 endcap modules supported by a series of 9 wheels at each end of the barrel. Each module is powered by its own independent, floating low and high voltage power supplies, referenced to ground at the detector shield. Correspondingly, each module has its own distinct cable chain all the way back to the service cavern. This presentation outlines the structure and specification of the SCT Power Supply System, including the high level control software and operational model. I. SYSTEM REQUIREMENTS Although the detector modules used in the barrel and endcap regions are geometrically very different, they are electrically very similar. The desire to provide each module with a single reference potential resulted in the adoption of a single, multi-wire, shielded cable to each module [1] and hence in the location of floating, programmable Low Voltage (LV) and High Voltage (HV) power supply channels together in each Power Supply (PS) crate. Voltage [V] Current [mA] Parameter Min. Typ. Max. Typ. Max. Vcc 0.0 3.5 5.1 90