Development and test results of a digital data transmission system for Liquid Krypton Calorimeter level 0 trigger system for the NA62 experiment at CERN

The NA62 experiment at the European Organization for Nuclear Research (CERN) Super Proton Synchrotron (SPS) aims to measure the Branching Ratio of the very rare kaon decay K
⁺
→ π
⁺
νν, collecting O (100) events with a 10% background to make a stringent test of the Standard Model. One of the main backgrounds to the proposed measurement is represented by the K
⁺
→ π
⁺
π
⁰
, decay. To suppress this background an efficient photo veto system is foreseen with the Liquid Krypton (LKr) Electromagnetic Calorimeter Level 0 (L0) trigger. The development of a high-performance as well as reliable digital data system addresses this issue providing a mean to have the right bandwidth and efficiency to transmit experimental data to and from the counting room. This paper describes the LKr L0 trigger system, with particular emphasis for what concerns a LVDS digital data link used inside the system. Some aspects relative to the test set-up implementation as well as protocol test used to evaluate and qualify the digital data system are also part of the paper.