Stephen Schuh Vacuum Controls Final Design 6 April 2006 Injector Vacuum Controls Hardware Final Design Review 6 April 2006

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Outline Introduction Vacuum system overview Vacuum controls overview Safety Interlocks and Interfaces Valve Interlocks Pump Interlocks Waveguide Vacuum Interlocks Failure modes Maintenance and spares Budget Schedule

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Review Committee Members Keith Kishiyama (Lawrence Livermore National Lab) - Chair Karen Fant or Dan Wright (to be determined) Kathleen Ratcliffe Ron Akre

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Charges to the Review Committee 1.Evaluate the presented design against LCLS physics and performance requirements. In particular: Does the proposed control system provide appropriate status and control signals to the vacuum system users (vacuum experts, physicists, operators)? Is the PLC adequate to perform all the required interlocking functions? Do the proposed valve interlocks adequately prevent the spread of vacuum leaks in the beam line? Does the proposed gun waveguide vacuum interlock adequately protect the gun from vacuum-related arcing? Do all the proposed waveguide vacuum interlocks adequately protect the klystrons from vacuum-related arcing? Are the proposed outputs to the MPS adequate to prevent the electron beam from striking a valve? Does the proposed plan to shut off ion pump power supplies after a smoke alarm adequately protect against fires in cable trays? 2.Identify any other technical issues not already addressed in the presented design 3.Determine if the presented schedule and plans for design, procurement, and installation are reasonable 4.Identify any safety or environmental issues that have not been addressed 5.Write a report of comments, findings, and recommendations

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Personnel Controls: Stephen Schuh (LCLS Controls) – vacuum software Tom Porter (SLAC Controls and Power Electronics) – vacuum hardware Mechanical: Leif Eriksson (LCLS) – beam line vacuum Jose Chan (LCLS) – RF waveguide vacuum Carl Rago (LCLS) – RF waveguide vacuum RF and Gun: Ron Akre (Klystron Dept) – klystron protection from vacuum arcs Dave Dowell (LCLS) – gun protection from vacuum arcs MPS: Stephen Norum (LCLS Controls) Arturo Alarcon (LCLS Controls) PPS: Patrick Bong (SLAC Controls and Power Electronics)

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Scope of Work Vacuum Mechanical / Vacuum Controls Close collaboration with mechanical vacuum group Treaty point is connector on beam line component Mechanical is responsible for pumps, gauges, valves Controls is responsible for cables, controllers, PLC, EPICS Interface document: Vacuum Controls Vacuum Mechanical (ICD ) Mechanical: LCLS Mechanical Vacuum Specifications (ESD ) Beam line component specifications Pressure requirements Controls: Vacuum Controls Requirements (ESD ) Status and control requirements Interlock requirements Interface requirements

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Injector Vacuum Schematic

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Linac X-Band Vacuum Schematic Laser Vacuum Schematic

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Vacuum Controls Block Diagram

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Vacuum Controls Architecture PLC Primary means of vacuum control system input and output Direct connection (24V digital or 0-10V analog) to gauge, pump, valve controllers Interlocks Connections to MPS, PPS, MKSU, VESDA, Ethernet Precedent: Same PLC used for SNS Vacuum System IOC Interface to LCLS global control system: archiving, remote control Connected to PLC by Ethernet Ether-IP driver to read and write PLC tags Auxiliary input/output with RS-232 No critical control functions

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Allen-Bradley ControlLogix PLC Programming Ladder logic format RSLogix software on Windows computer Logic stored in nonvolatile memory – won’t lose logic on power failure “Master” crate PLC Processor: model 1756-L61, 2MB nonvolatile memory Ethernet connection to global control system ControlNet connection to other crates Inputs from PPS, VESDA Outputs to MPS, RF System 24V digital and 0-10V analog connections to gauge controllers Uninterruptible Power Supply (UPS) “Slave” crates ControlNet connection to master crate 24V digital and 0-10V analog connections to pump and valve controllers

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Valve Control EPICS Remote control and status PLC Interlock Logic Valve status to MPS PPS access state from PPS Solenoid control A-B PLC Two Valve Control Panel No logic, sends signals to PLC Valve control mode switch EPICS: Commands from EPICS Local: Buttons on panel J-Box: Key switch on J-Box – Interlocks bypassed Closed: locked closed Local valve status and control (only in Local mode) Interlock status Tunnel valve hardware Solenoid valve Air supply, air reservoir, pressure regulator, air switch J-Box provides local status and control (only in J-Box mode)

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Gamma Digitel Multiple Pump Controller Controller Configuration Two high voltage channels 5.6kV output, “Medium” supply: 100mA max Positive polarity for noble diode type pumps PLC Status/Control Process set point status (4 per controller) Analog pressure and voltage signals Pump on/off control RS-232 Status/Control Diagnostic info about supplies Read and change set points Cables No SafeConn cables Cables and connectors rated for 10 kV Some controllers support multiple pumps on one channel One long haul cable per pump Cable junctions in control racks

Stephen Schuh Vacuum Controls Final Design 6 April 2006 MKS 937A Gauge Controller Controller configuration 2 cold cathode gauges and 2 convection enhanced Pirani gauges “Fast response” cold cathode gauges – 15 msec instead of 100 msec standard Internal interlock to shut off cold cathode gauge based on pressure read by Pirani PLC Status/Control One process set point per gauge Analog pressure signals RS-232 Status/Control View and change set point configuration

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Granville-Phillips 307 Gauge Controller Controller configuration 1 hot filament gauge and 1 Convectron gauge SLAC modifications for input/output card PLC Status/Control Process set points (4 per controller) Gauge on/off control Analog pressure signals

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Safety Vacuum safety issues addressed at LCLS Vacuum Safety Review (September 28, 2005). Safety review materials posted on the web: Electrical Equipment Inspection Program (EEIP) approval for vacuum controllers: Gamma Digitel ion pump controller: LLNL AHJ certification being entered into SLAC’s EEIP database MKS 937A: EEIP approval not yet obtained Granville-Phillips 307 gauge controller: EEIP approval not yet obtained Allen-Bradley ControlLogix PLC: All components are UL-listed Ion pump high voltage cable plant Power supplies will be configured for 5.6 kV. Output of 7 kV is possible with internal power supply hardware changes All connectors and cables rated for 10 kV Pump cables will be type C coaxial cables. Gamma SafeConn cables will not be used SafeConn interlock cannot be relied on, per SLAC electrical safety officer Even with SafeConn cables, lock-and-tag would still be required for disconnecting cables SafeConn cables more expensive (factor of 10), take more tray space (factor of 2) Gamma SafeConn cable not low smoke, non-halogenated; type C cable is

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Valve Interlocks Requirements: Automatically close valves to isolate regions with bad vacuum Automatically close valves in controlled or permitted access Notify MPS when valve is closed to prevent beam from hitting valve 100 msec response time (valves are slow valves with ~500 msec closing time) Solution: Set points stored in gauge controllers and pump controllers PLC receives set point status from controllers (24V digital inputs) PLC receives access state from PPS (24V digital inputs) PLC controls valve solenoid (24V digital output) PLC sends valve state to MPS (24V digital output) Interlock logic is a PLC ladder logic routine: monitor inputs, close valve if an input is faulted

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Pump Interlocks Requirements: Turn off injector vault ion pumps if injector vault or laser room VESDA smoke detector asserts alarm Injector vault cables run over laser room ceiling Solution: PLC receives status of injector and laser room VESDA systems (24V digital inputs) PLC controls pump controller high voltage (24V digital outputs) Interlock logic is a PLC ladder logic routine: monitor VESDA status, turn off pumps if VESDA system sends alarm

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Waveguide Vacuum Interlocks Purpose: Inhibit RF output from klystron if vacuum pressure in RF waveguide is high, in order to avoid arcing. Arcing could damage RF windows or the RF gun. Background: Existing waveguide vacuum interlock for linac klystrons: Measure pressure at output of klystron If pressure exceeds set point, send fault signal to Modulator Klystron Support Unit (MKSU) MKSU inhibits RF output from klystron Features of existing interlock: Fast: gauge controller wired directly to MKSU Simple: one gauge per klystron Some existing interlocks are more complicated: Positron source, PEP injector Multiple gauges and pumps are interlocked to each klystron

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Existing Waveguide Vacuum Interlocks

Stephen Schuh Vacuum Controls Final Design 6 April 2006 LCLS Waveguide Vacuum Interlock Requirements Modify waveguide vacuum interlocks for the following klystrons: 20-6: New waveguide directs RF output to LCLS Gun 20-7: New waveguide directs RF output to L0-A in LCLS injector 20-8: New waveguide directs RF output to L0-B in LCLS injector 20-5: New waveguide directs RF output to TCAV0 in LCLS injector 21-2: New waveguide directs RF output to X-Band section in Sector 21 Goals for modified interlocks: Monitor pressure everywhere in waveguide, not just at klystron output Response time: at most 8 msec slower than existing system (8 msec is 1 beam pulse at 120 Hz)

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Proposed Changes to Waveguide Vacuum Interlocks

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Wiring Diagram: Waveguide Vacuum Input to MKSU

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Response Time of New Interlock Gauge controller or pump Controller: Cold cathode gauge controller response time is 15 msec Pump controller response time is 650 msec PLC logic: <4 msec Response time estimate of 3.6 msec per Allen-Bradley worksheet (see Design Report, Appendix G) Response time <3 msec measured for ControlLogix PLC at SNS (see Design Report, Appendix F) External Relay: 2 msec (see Design Report, Appendix H) Total: 6 msec + gauge/pump response time. Meets requirement of 8 msec + gauge/pump response time.

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Alternative: Use Hardware Summary Box Instead of PLC

Stephen Schuh Vacuum Controls Final Design 6 April 2006 PLC vs Hardware Summary Box PLC Advantages No additional gauge / pump wiring needed. All gauges & pumps already wired to PLC PLC hardware well suited to interlocking Easy to modify interlock logic if desired Disadvantages PLC adds ~5 msec to response time Rely on vacuum PLC for RF interlock Hardware Summary Box Advantages: Faster interlock Proven to work at positron source klystrons RF interlock independent of vacuum PLC Disadvantages Additional hardware summary box needed Additional gauge and pump wiring required Difficult to change interlock logic

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Vacuum Controls Hardware Failure Modes System Power Failure Valves close, pumps turn off, interlock outputs go to safe states PLC Power Failure Master crate powered by UPS Slave crates can safely be powered off. Interlock outputs go to safe states. Disconnected PLC Cable: Set point cables appear as faults when disconnected Outputs to other subsystems appear as faults when disconnected 24V Power Supply Failure Valves close, set points appear faulted, interlock outputs go to safe states Component Power Failure: Interlock outputs go to safe states Network Failure: PLC performs all interlocks without need for network Loss of Site Compressed Air Pressure Air reservoirs hold enough air to close each valve once

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Installation, Maintenance, Spares SLAC Mechanical Fabrication Department (MFD) maintains mechanical hardware and pigtails SLAC Controls & Power Engineering (CPE) installs, tests, and maintains controls equipment All work is performed by qualified CPE personnel Installation, testing, and maintenance of vacuum equipment will follow established CPE procedures Work on high voltage equipment or cables will follow CPE high voltage procedures CPE determines need for spares; most components are commercial off-the-shelf devices with short lead times

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Budget Available Money for Injector and Linac up to Undulator WBS Injector: $128k WBS Linac and Linac-to-Undulator (LTU): $174k Money Needed for Injector and Linac through BC1 ItemCountUnit CostTotal Cost Gamma Digitel Multiple Pump Controller20$3686$73724 MKS 937A Gauge Controller Granville-Phillips 307 Gauge Controller12545 Valve Control Hardware: Air supply, J-Box, A-B PLC Two Valve Control Panel Injector PLC Hardware40000 EPICS IOC15000 Terminal Server Total$149805

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Schedule: Design, Prototype, Software

Stephen Schuh Vacuum Controls Final Design 6 April 2006 Schedule: Hardware Installation, Testing