Status of the Readout Electronics for Triple-GEM Detectors of the CMS GE1/1 System and Performance of the Slice Test in the 2017-18 LHC Run

In this contribution, we will present the status of the readout electronics system for the triple-GEM detectors of the GE1/1 system which is planned for installation into CMS in 2019-2019 (LS2), as well as the performance of the ten slice test detectors which were installed into the CMS endcap in January 2017. These slice test detectors are read out on the front end using 24 VFAT2 chips and a corresponding v2 optohybrid board, and from the back end using a microTCA crate containing 24 VFAT2 chips and AMC13 boards. Two of the ten detectors will also include temperature sensors, and are powered via a multichannel power supply, as the final GE1/1 detectors will be. Data was recorded throughout the 2017 run, using both cosmic ray muons and LHC collisions. The lessons learned from this slice test allowed for the further development of the final GE1/1 v3 electronics which will be used in the LS2 installation. These new detectors will be read out by the VFAT3 chip, which runs at a frequency of 320 MHz, four times higher than the frequency of the VFAT 2 chip, as well as the v3 optohybrid board which is equipped with a Xilinx Virtex 6 FPGA and three GBT chipsets. The on-detector electronics are powered via ten FEAST DC-DC converters. In February 2018, two such v3 detectors replaced two of the v2 slice test detectors. This contribution will report on the improvements made to the electronics in view of the installation of GE1/1, the overall performance of the slice test detectors, and on the very first results of the final GE1/1 v3 electronics obtained in CMS.