A Burn-In Apparatus for the ATLAS Tile Calorimeter Phase-II Upgrade Transformer-Coupled Buck Converters

The upgrade of the A Toroidal LHC ApparatuS (ATLAS) hadronic Tile Calorimeter (TileCal) Low-Voltage Power Supply (LVPS) forms a part of the Phase-II Upgrade preparations undertaken by the ATLAS experiment for the data taking during the High-Luminosity Large Hadron Collider era. This paper serves to provide a detailed overview of the development of a Burn-in test station for an upgraded LVPS component known as a Brick. The production, quality assurance testing, and all associated apparatus are being jointly undertaken by the University of the Witwatersrand (Wits) and the University of Texas at Arlington (UTA). These Bricks are radiation-hard transformer-coupled buck converters that function to step-down bulk 200 VDC power to the 10 VDC required by the on-detector electronics. To ensure the high reliability of the Bricks, once installed within the TileCal, a Burn-in test station has been designed and built. The Burn-in station functions to implement a Burn-in procedure on eight Bricks simultaneously. This procedure subjects the Bricks to sub-optimal operating conditions, which function to accelerate their ageing, as well as to stimulate failure mechanisms. This results in elements of the Brick that would fail prematurely within the TileCal failing within the Burn-in station or experience performance degradation that can be detected by follow-up testing effectively screening out the non-performative sub-population. The Burn-in station is of fully custom design in both its hardware and software. The development of the test station will be explored in detail; the preliminary Burn-in procedure to be employed will be provided; the preliminary and final commissioning of the test station will be presented. The paper will culminate in the presentation and discussion of the Burn-in of a V8.4.2 Brick and the future outlook of the project.