Experiences with the ATLAS pixel detector optolink and researches for future links

The optical links for the ATLAS Pixel detector has been passed several steps of development. After the design and production of the components itself, various tests have been performed on individual components on smaller or larger parts of the full system. Finally, the links were commissioned in situ after installation. A lot of experience has been gained and this should be used to step into the research on future optical links for the Pixel detector itself, but also for other detectors. In this paper the procedure of the commissioning work of the ATLAS Pixel optical link and observed issues on the system layout and function are discussed and brought into an outlook for future optical link designs.

I. Introduction

The Atlas Pixel detector has been installed in its final place into the ATLAS cavern in July 2007. After providing all the necessary connections, the final testing and commissioning has been performed before the first beam was circulated through the LHC in September 2008. The connection between the 1744 detector modules and the readout electronics in the counting room is done via optical links, that have to be commissioned and tuned in order to be able to send commands to and receive data from the modules. Tests for optical and electrical functionality of components during production and assembly sorted out failing parts. The commissioning work on the installed detector showed more than 97% of the system being functional.