Low Voltage Power for the ATLAS New Small Wheel Muon Detector

The New Small Wheel (NSW) is an upgrade for enhanced triggering and reconstruction of muons in the forward region of the ATLAS detector at CERN's Large Hadron Collider. The large LV power demands necessitate a point-of-load architecture with on-detector power conversion. We present final results from an extensive campaign to test commercial power devices in radiation and magnetic fields, and describe an alternate solution based on a radiation-hard power conversion ASIC (the FEAST) produced by CERN microelectronics. We detail the challenges and solutions in integrating this device into the New Small Wheel, and outline the full resulting power system.