Trigger Synchronisation Unit LHC Beam Dump System LHC Beam Dump System Technical Audit
Topics Topics • Requirements • Architecture Architecture – Timing unit – Dump request client interface D li i f – Dump request management – Supervision & Diagnostic • Design • Design January 2008 CERN - A. ANTOINE 2/14
Layout (Reminder) Layout (Reminder) Trigger Trigger Power Re-trigger Synchronisation Synchronisation Fan-out Fan out Trigger Trigger Box Box Unit Unit Generator 1 Branch TSU TFO PTU RTB A Branch PTU RTB B F rev rev Generator 15 Client Branch TSU TFO PTU RTB A Interface f Branch RTB PTU B RTD Re-trigger lines Fail-safe Fault-tolerant January 2008 CERN - A. ANTOINE 3/14
Requirements Requirements • 3 µs beam abort gap synchronisation • RF-signal recovery capability RF signal recovery capability • Multiple Dump request client detectors • Remote diagnostic • Fault tolerant behavior Fault tolerant behavior • Low failure rate (p = 5.52.10 -10 / year) • Injection Kicker AGK window generation January 2008 CERN - A. ANTOINE 4/14
Architecture Architecture DPDT : Dump Trigger Pulse Trains TRGS : Trigger Request gate signal SBDT : Synchronous Beam Dump Trigger ABDT : Asynchronous Beam Dump Trigger January 2008 5/14
Timing unit Delays RF TSU Generator Revolution & Magnet (PTU) Frequency TFO 1 25 δ 1 δ 1 δ 2 δ 3 δ 4 δ 5 δ 6 • δ 1 : Transmission speed between RF transmitter & LBDS • δ 2 : TSU delay & TFO with compensation delay • δ 3 : f(Magnet position) = cable length delay adjustment ( g p ) g y j 3 • δ 4 : f(Generator) = Turn on delay compensation • δ 5 : cable length delay • δ 6 δ 6 : ceramic chamber effect delay : ceramic chamber effect delay ⇒ TSU with Configurable Delay TSU with Configurable Delay January 2008 CERN - A. ANTOINE 6/14
Timing unit RF-signal transmission f Re volution f Re volution • Optical Fiber Transmission • Optical / electrical conversion by AB/RF Rx & Tx board • ECL 5 ns / 1V / 50 Ω signal converted to CMOS by BT/EC • NO REDUNDANCY ⇒ ADPLL as clock recovery ADPLL as clock recovery January 2008 CERN - A. ANTOINE 7/14
Timing unit ADPLL WORD × f CLK f = NCO N 2 WORD × f CLK f = NCO N 2 f CLK = 100 MHz Φ K ⋅ ( Z − 1 ) PLL = = 2 θ Z + ( K − 2 ) ⋅ Z − ( K + 1 ) PLL PLL − 1 − 1 Z Z January 2008 CERN - A. ANTOINE 8/14
Dump Request Client Dump Request Client • Based on CPLD technology in redundancy B d CPLD t h l i d d • Each CPLD is program by a different author • 3 different client interfaces : 3 different client interfaces : – Hardware (outside CPLDs) : • Current loop – Beam loss Monitor Beam loss Monitor • Logical state detector – Programmable logic Controller – Inject & Dump – Firmware (inside CPLDs) : • Square wave frequency detectors – Beam Interlock System – Beam Energy Tracking System ki S => All dump requests issue LBDS Synchronous trigger & a one => All dump requests issue LBDS Synchronous trigger & a one turn delay (added by RTD) asynchronous trigger turn delay (added by RTD) asynchronous trigger January 2008 CERN - A. ANTOINE 9/14
Dump Request Client Frequency detectors • 2 frequency detector types – Fast detector • Detects signal activity within a short integration period (250 ns) • One missing pulse tolerant • Acts as a low pass filter • Acts as a low-pass filter => No Frequency drift detection => No Frequency drift detection – Slow detector Slow detector • Calculate the real input frequency • Long integration period (200 µs) Long integration period (200 µs) => Frequency drift detection => Frequency drift detection January 2008 CERN - A. ANTOINE 10/14
Dump Request Management Dump Request Management • Discreet components • Discreet components • Synchronous & asynchronous trigger output • Local operation allowed (Test acceptance) l ll d ( ) • Supervision & Diagnostic unit management January 2008 CERN - A. ANTOINE 11/14
Supervision & Diagnostic Supervision & Diagnostic • Arming process (before injection allowed) A i (b f i j ti ll d) – Check all sub entities state – Initiate ADPLL pull-in process => Wait ADPLL lock • Synchronisation check between TSU-A & TSU-B (See table) • Dump Request Management unit control • VME comm nication for remote diagnostic • VME communication for remote diagnostic TSU-A TSU-A TSU-B TSU-B Status Status Action Action OK OK All OK nothing TSU-A Dump immediately OK OK FALSE FALSE TSU B oscillator failure TSU-B oscillator failure TSU B disable its own dump request TSU-B disable its own dump request TSU-B Dump immediately FALSE OK TSU-A oscillator failure TSU-A disable its own dump request FALSE FALSE FALSE FALSE Ti Timing failure i f il TSU A & TSU B d TSU-A & TSU-B dump after 5 cycles ft 5 l January 2008 CERN - A. ANTOINE 12/14
Design Design • VME VME crate implementation t i l t ti CIBO FPGA • 2 redundant electronic boards with: – 1 CIBO interface (AB/CO - BIS) – 2 independent CPLD for the dump request client interface – 1 FPGA for synchronisation, VME supervision & communication CPLD – 1 Dump Request management unit (Discrete components ) it (Di t t ) – A VME interface • VME backplane for crosscheck communication • VME interface boards DRM January 2008 CERN - A. ANTOINE 13/14
Next Next … • What’s behind the TFO & RTD boxes ? January 2008 CERN - A. ANTOINE 14/14
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