Diagnostic System for Low Level RF Control System for VUV-FEL

Diagnostic System for Low Level RF Control System for VUV-FEL Tomasz Jeżyński • Outlook • VUV-FEL • LLRF • Source of perturbations • Diagnostic System for LLRF Technical University of Łódź, Poland Deutsches Elektronen-Synchrotron, Germany

VUV-FEL - the pilot facility for the XFEL • 260 m long (tunel 100 m) • 6 Cryo-modules • TESLA technology • 48 superconductive cavities • Development platform for XFEL Tomasz Jezynski

no access during operation • no service tunnel • risk of radiation damage Tunnel Place for electronic Tomasz Jezynski

Outlook • VUV-FEL • LLRF • Source of perturbations • Diagnostic System for LLRF Tomasz Jezynski

Cavities ~ VM . . . RF Switch ADC ADC HP Amplifier Down converters . . . DAC DAC DSP 7 8 ... Control System Control System in VUV-FEL MO Tomasz Jezynski

LLRF - requirements • Electrical field : 30 MV/m • Required field stability : 10-5 in amplitude, 0.01° in phase • Continuous operation is required one maintenance day per month Tomasz Jezynski

LLRF– Goals • Provide: • stable RF field in cavity during beam • continuous operation Tomasz Jezynski

Source of perturbation Hardware • Hardware • MO – phase • VM – Pin, nn • Klyston – Pout = f(Pin) • RF Power distribution • Probes – individual char • Mixers – nn, offset • ADCs – nn, offset • DACs – nn, offset • Timing – time & temp. • Power Supplies • Noise level • ... Software • Software • Numerical errors • Calibration • Parameters • Control System • ... Tomasz Jezynski

Diagnostic System - Goals The diagnostic system cannot increase reliability! but can decrease maintenance cost (minimize time and man power necessary to repair) provide the high availability Tomasz Jezynski

Diagnostic System - Goals Diagnostic have to be: • Cheap • Flexible (easy modification, extend...) • Failures of diagnostic cannot stop operation Tomasz Jezynski

Cavities ~ VM . . . 5 1 3 2 4 RF Switch ADC ADC HP Amplifier Down converters . . . ... DAC DAC DSP 8 7 ... Control System Monitoring MO Tomasz Jezynski

Phase between two points in time Tomasz Jezynski

Tomasz Jezynski

Unacceptable data from the system Tomasz Jezynski

Cavities ~ VM . . . 3 6 4 2 1 7 8 5 RF Switch ADC ADC MO HP Amplifier Down converters . . . ... • Tests: • Hardware • Algorithm DAC DAC DSP DAC DAC Control System Diagnostic Tomasz Jezynski

~ 6 7 8 9 2 3 1 5 4 ADC ADC ... DAC DAC DAC DAC Sig. Gen. Diagnostic & Calibration Cavities VM . . . RF Switch MO HP Amplifier Down converters . . . DSP Control System Tomasz Jezynski

2 x optolink 3.125 Gbps 10 x ADC, 14 bits, 105 MMz 4 x DAC, 14 bits, 200 MMz Digital IO Ethernet Tomasz Jezynski

Main panel - first result (timing) Timing requires dedicated hardware ! Tomasz Jezynski

Diagnostic System for VUV-FEL • Monitoring • Diagnostic • Calibration Tomasz Jezynski

Monitoring • Error detection • Timing signals (synchronization, phase) • Pfor & Pref • Probes • Field stability (RMS, p-p, ...) • Detuning • Loaded Q • Limits of set value • ... Tomasz Jezynski

Diagnostic • Detect malfunction • Locate damage hardware • Crate, board, input • Perform components tests • ADCs, DACs • Interfaces • Memory, DSP blocks ... • Timing distribution • ... Tomasz Jezynski

Calibration • timing • probes • vector sum • ADCs and DACs offset • downconverter • attenuators • ..... Tomasz Jezynski

What we want to do? • Provide possibility to read data form different points of the system • Design an universal diagnostic interface and implement it to all electronic boards • Integrate diagnostic elements in control system • Sources of test signals • RF Switches • ... • Provide self-diagnostics for all boards Tomasz Jezynski

THE END Tomasz Jezynski

Diagnostic System for Low Level RF Control System for VUV-FEL