ATLAS FTK a - very complex - custom super computer

17th International Workshop on Advanced Computing and Analysis Techniques in Physics Research

物理学;计算机科学

Kimura, N.^1

Aristotle University of Thessaloniki, Thessloniki, United Kingdom^1

关键词: Associative memory;    ATLAS detectors;    Detector coverages;    High-level triggers;    Highly parallels;    Reliable detection;    Tracking detectors;    Trigger performance;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/762/1/012005/pdf
DOI  :  10.1088/1742-6596/762/1/012005

学科分类：计算机科学（综合）

来源: IOP

【 摘 要 】

In the LHC environment for high interaction pile-up, advanced techniques of analysing the data in real time are required in order to maximize the rate of physics processes of interest with respect to background processes. The Fast TracKer (FTK) is a track finding implementation at the hardware level that is designed to deliver full-scan tracks with pTabove 1 GeV to the ATLAS trigger system for events passing the Level-1 accept (at a maximum rate of 100 kHz). In order to achieve this performance, a highly parallel system was designed and currently it is being commissioned within in ATLAS. Starting in 2016 it will provide tracks for the trigger system in a region covering the central part of the ATLAS detector, and will be extended to the full detector coverage. The system relies on matching hits coming from the silicon tracking detectors against one billion patterns stored in custom ASIC chips (Associative memory chip -AM06). In a first stage, coarse resolution hits are matched against the patterns and the accepted hits undergo track fitting implemented in FPGAS. Tracks with pT> 1GeV are delivered to the High Level Trigger within about 100 ps. Resolution of the tracks coming from FTK is close to the offline tracking and it will allow for reliable detection of primary and secondary vertexes at trigger level and improved trigger performance for b-jets and tau leptons. This contribution will give an overview of the FTK system and present the status of commissioning of the system. Additionally, the expected FTK performance will be briefly described.