The Associative Memory system for the FTK processor at ATLAS

Experiments at the LHC hadron collider search for extremely rare processes hidden in much larger background levels. As the experiment complexity, the accelerator backgrounds and instantaneus luminosity increase, increasingly complex and exclusive selections are necessary. We present results and performances of a new prototype of Associative Memory (AM) system, the core of the Fast Tracker processor (FTK). FTK is a real time tracking device for the ATLAS experiment trigger upgrade. The AM system provides massive computing power to minimize the online execution time of complex tracking algorithms. The time consuming pattern recognition problem, generally referred to as the "combinatorial challenge", is beat by the AM technology exploiting parallelism to the maximum level. The Associative Memory compares the event to pre-calculated "expectations" or "patterns" (pattern matching) at once and look for candidate tracks called "roads". The problem is solved by the time data are loaded into the AM devices. We report on the tests of the integrated AM system, boards and chips. The prototype has an impressive network of high speed, long serial links, successfully tested for their task solving the huge data distribution problem. We report also on the cooling tests and the expectations of power consumption of the system.