MICROTCA.4 BASED OPTICAL FRONTEND READOUT ELECTRONICS AND ITS APPLICATIONS K. Przygoda † , L. Butkowski, M. K. Czwalinna, H. Dinter, C. Gerth, E. Janas, F. Ludwig, S. Pfeiffer, H. Schlarb, C. Schmidt, M. Viti, Deutsches Elektronen-Synchrotron, Hamburg, Germany R. Rybaniec, Warsaw University of Technology, Warsaw, Poland Abstract In the paper the MicroTCA.4 based optical frontend readout (OFR) electronics and its applications for beam arrival time monitor (BAM) and fast beam based feed- back (BBF) is presented. The idea is to have a possibility to monitor the modulation density of the optical laser pulses by the electron bunches and apply this information for the BBF. The OFR composed of double width fast mezzanine card (FMC) and advanced mezzanine card (AMC) based FMC carrier. The FMC module consists of three optical channel inputs (data and clock), two optical channel outputs (beam arrival time), 250 MSPS ADCs, clock generator module (CGM) with integrated 2.8 GHz voltage control oscillator (VCO). The optical signals are detected with 800 MHz InGaAs photodiodes, conditioned using 2 GHz current-feedback amplifiers, filtered by 3.3 GHz differential amplifiers and next direct sampled with 16-bit 900 MHz of analog bandwidth ADCs. The CGM is used to provide clock outputs for the ADCs and for the FMC carrier with additive output jitter of less than 300 fs rms. The BAM application has been implemented using Virtex 5 FPGA and measured with its performance at Free Electron LASer in Hamburg (FLASH) facility. INTRODUCTION The Micro Telecommunication Computing Architecture (MicroTCA) is a standard in Telecommunication from several years. Nowadays more often high energy physics research centres are trying to migrate from commonly used Versa Module Europa (VME) to more compact, modular, redundant solutions offered by MicroTCA, es- pecially generation four of the standard. The Deutsches Elektronen-Synchrotron (DESY) in Hamburg in Germany is a leading institute which developing, designing, testing and even commercializing general purpose and applica- tion specific modules using this modern technology. Moreover, the next generation light sources such FLASH and European X-Ray Free Electron Laser (E-XFEL) ac- celerators have been decided to be fully controlled and monitored with its crucial parameters by MicroTCA.4 [1]. The scope of the paper is to summarise the several year research and development (R&D) program on developing direct sampling OFR electronics [2]. The OFR electronics have been optimized to get the best achievable perfor- mance when considering the optical to RF conversion of the laser pulses, ADC stability and fast data processing by FPGA’s. Fast digital feedback information can be sent out using small form-factor pluggable (SFP) optical modules allowing data transfers up to 10 Gbps. The OFR electron- ics can be efficiently applied for several applications. Within the paper we are presenting its usage for BAM and BBF experiments. BEAM ARRIVAL MONITOR AND BEAM BASED FEEDBACK APPLICATIONS The BAM signal creation, detection and analysis in the electron bunch arrival time monitor is split into several subsystems, each fulfilling a particular function as shown in Fig. 1. Figure 1: The block diagram of BAM detector. The RF module which consists of four broadband pickups mounted in the beam tube is applied in order to capture the electric field induced by the passing electron bunches. The signals of opposite pickups are combined for a re- duced position dependence of the measurement, resulting in two independent RF channels for the arrival time detec- tion: course and fine. Than the electro-optical modulator (EOM) unit is introduced mainly for translating the RF signals into an amplitude modulation of time-stabilized, ultra-short laser pulses provided by the Master Laser Oscillator (MLO) synchronization system in order to achieve a high temporal sensitivity. The optical frontend electronics need to be installed at the end of the system for signal processing and control of the individual subsys- tems [3]. Figure 2: The block diagram of BAM signal detection and calibration. The beam arrival time is calculated using peak and base- line values of the first modulated (mod) and first unmodu- ____________________________________________ † konrad.przygoda@desy.de Proceedings of IBIC2016, Barcelona, Spain MOPG13 BPMs and Beam Stability ISBN 978-3-95450-177-9 67 Copyright © 2016 CC-BY-3.0 and by the respective authors