SNS Machine Protection System

1
SNS Machine Protection System

• EPICS Workshop
• April 27, 2005
• Coles Sibley

2
Intro

1. System overview
2. Hardware summary
3. Input Summary
4. Software tools
5. Configuration Control
6. Tools needed for MPS

What to avoid.
3
MPS Design Assumptions

• Four layers of protection!
• Hardware PLC
• Hardware / Software (Fast Protect Latched)
• Hardware / Software (Fast Protect Auto Reset)
• Software (Run Permit System)
• Machine Protection System is not a Safety Class
  or Safety Significant System.
• SNS will be built and commissioned in Phases, MPS
  must accommodate this schedule, (Flexible and
  Reliable).
• Reliability The Machine Protection System must
  inhibit the beam when required. It must fail in
  a SAFE state.
• Availability The machine availability should be
  as high as possible. The MPS must be easy to
  configure and have a friendly operator
  interface. False trips must be minimized.

4
Layers of Protection

• Run Permit System (1 second)
• Verifies IOC configuration and beam line
  equipment status.
• MPS masking, Beam Power limit verification
• Fast Protect Auto Reset (20 microseconds)
• Beam Loss Monitors
• Beam Current Monitors
• Fast Protect Latched System (20 microseconds)
• Power Supply status, RF, Kicker status
• System cooling status (Collimators, dumps, etc)
• etc.
• MPS PLC ( 33 msec)
• Magnetic Field limit(s) verification
• Beam Dump monitoring

5
Machine Availability

• MODE masks are defined by MPS and Operations, not
  easily changed.
• Allows beam when invasive diagnostics are used
  only for SAFE beams.
• Easy OPI for verifying Mode Masks.
• Mode masks are applied pulse to pulse from timing
  system
• Allow easy bypass (Software Masking) for selected
  inputs
• Different rules for commissioning and operations
• Commissioning, FPAR devices can be masked
• Commissioning, FPL subset of Quads can be
  masked, all dipoles and rest of quads need ASD
  Operations approval.

6
Machine / Beam Mode Definitions

• Machine mode selected by Key switch in control
  room, Beam Mode selected by Key or software.
  Switches read by MPS PLC system.

• Machine Modes
• MEBT Beam Stop
• CCL Beam Stop
• Linac Dump
• Injection Dump
• Ring
• Extraction Dump
• Target

• Beam Modes
• Diagnostics (10 usec)
• Diagnostics (50 usec)
• Diagnostics (100 usec)
• Full Pulse Width (1 msec)
• Full Power (Depends on Dump)

7
MPS Timing System checks

• RTDL Heartbeat (PCI Clock)
• Event link heartbeat
• Driver IOC heartbeat
• Hardware Configuration file checks against actual
  HW settings
• Machine / beam mode (lt 3.3e-10 probability of
  undetected fault)
• 8 bit CRC (1/256)
• 8b bits encoded in 24 bit frame for single bit
  errors
• 24 bit CRC on all frames (1/16777215)
• Mode Masks
• mask /maskgtgt8 (single bit upset errors)
• Software verification of masks (Configuration
  control)
• Checksum of masks (File integrity)
• Cable Status monitored

8
MPS Hardware

• Technobox PMC reconfigurable IO card
• 10K70 Altera
• (20k200 newer)
• Up to 5 per IOC with PMC_Span, 16 inputs each

9
MPS PMC Module (Also nice generic digital IO
module)
10
MPS Fast Protect System Layout
11
MPS Input Summary (August 5005)

• 27 new chassis installed
• Copper phased out, using fiber
• Post CD4, corrector PS status will be used
• Inputs will quadruple for CD4

12
MPS PLC Control Net Layout
13
PLC Remote Inputs

• Machine made, Beam Mode selection
• Emergency Crash
• Trigger Control sanity checks
• Timing System handshakes
• Target (or Dump) Status
• Pressure, Temperature
• Flow, Vacuum status
• Power supply current monitors
• Quads Hi window, Dipoles, Hi and Off windows.
• Steering correctors Window (RTBT only)

14
Injection Dump inputs

• Beam Current Monitor (Not in baseline, Hardware
  chosen)
• P-P Pulse Width verification
• Beam Power, Integrated Beam Current
• No direct current density or beam position
  monitors on dump windows or target

15
Run Permit (Software) Layers

• Configuration Control
• Mode masks
• SW masks
• EPICS dbs
• Archiver files
• Alarm Handler (?)
• Timing System dbs
• Post Mortem
• First fault
• Waveform viewer

• Software monitoring
• PSs Field
• RF, Phase and amplitude
• BLM HV
• Selected set point limits
• Timing System pattern generator
• Integrated Beam Loss (software MPS trip)

16
MPS Applications

• First hit and total trips entered every day at
  midnight
• MPS First Hit stats since Sep 19, 2004
  000000RFQ_LLRFHPM1FPAR_Src_chan_status,
  counts 2806DTL_LLRFHPM5FPAR_CCL_BS_chan_statu
  s, counts 2176DTL_LLRFHPM6FPAR_CCL_BS_chan_st
  atus, counts 755CCL_MPSFPAR_Sublink04DFPAR_CC
  L_BS_chan_status, counts 624
• Noise was initially a big problem. Noise
  reduction, filters, fiber installations have
  mostly eliminated the problem.

• MPS First fault Now runs as server client
  application
• Detects first fault, tracks total faults

17
MPS Applications

• Input Status Summary
• Shows input status and consequences of changing
  beam modes or machine modes.
• Mode Mask Verification
• Replaces spreadsheet, paper and pencil
• Replaces tedious task of verifying 35 modes per
  input 350 inputs 12250 individual checks
• Automated Verification (in progress)
• Check inputs
• Trip and verify MPS
• Reset, turn back on
• Generate report to e-log

18
MPS Bypass Request
Enter new bypass request Edit request Approve
request Install request Remove request View
existing Open requests View history
19
Software tools needed

• 3D Waveform viewers
• BLM waveform vs. time or accelerator location
• Scope Application (Correlated waveforms)
• RF vs BLM waveforms
• Injection / Extraction kickers vs BLM
• BCM vs. BLM
• Post Mortem Tools
• First fault
• BLM loss model vs component
• BLM waveform signatures (Archive waveform viewer)
• Fast vs Off Energy vs Halo
• MAID (Maximum allowable intra pulse difference)
  Full Power operation
• Verifies beam to target parameters acceptable
  before allowing next pulse (or as fast as
  possible)
• Beam Scheduler / pattern generator