Minutes BWS Upgrade: Electro-Mechanical Design Meeting #14 -- 19th September2016 --

Participants: R. Veness, F. Roncarolo, J. Emery, P. Andersson, D. Gudkov, W. Andreazza, J.L. Sirvent, C. Vulliez

Agenda( https://indico.cern.ch/event/569130/)

1. Post Mortem of the SPS BWSRE Incident and Intervention:

1.1 Causes of the Incident (J.Emrey, F.Roncarolo)
  • An error (glitch) occurred during testing BWS Prototype without beam in the processing of the shaft position.
    • Problem never seen on lab. tests and cause under investigation.
    • Error tricked control system to believe that shaft position was off by multiple turns forward.
    • Position control spin the scanner backwards multiple turns to compensate (the wrong measured) position
    • Multiple turns broke kapton wires (for wire continuity measurement).
    • One wire was projected on the middle of the beam pipe causing loses that leaded to beam dumps.
    • Around 14 turns recorded backwards with a speed of 150rad/s (max speed reachable by scanner system)
  • Same firmware than Dec 2015 testing, the only difference is the triggering system used
    • New system installed to make synchronous triggers
    • Intended to synchronize scan movement with machine cycle and acquisition system.
  • Mitigation plans:
    • 1. Firmware release to avoid more than 2 turns
    • 2. Code re-factorization for noise immunity.
    • 3. Possible usage of optical sensors for control improvement
    • 4. Galvanic ground separation with external systems.
    • 5. Extensive testing of SPS proto located on 867 proposed.
1.2 Intervention and current situation (R. Veness, W. Andreazza)
  • Friday night (9/09/2016) Scanner was removed from its tank.
  • The tank was closed with a blank flange.
  • Some vacuum leakages identified during operation (Flange & gasket out of tolerance)
  • The re-installation of the instrument without kapton wires was agreed.
  • It was observed a hard point, and some noise, during manual movement.
    • After some manual movements, the noise / hard point, disappeared (residuals on ball bearings?)
  • Scanner was installed and tested on Wednestay (14/09/2016).
    • Movement show correct behaviour.
    • One of the two optical sensors seems to have been damaged.

2. Status of work on the PSB Prototype:

2.1 Mechanics (G.Gudkov)
  • PSB prototype assembly tests performed on CW37.
  • Mounting readiness at 75%, the mounting continues during CW38.
    • No major assembly problems observed so far.
  • Disk status:
    • 3 Complete disk produced (Diamond turning)
    • Tests shown not a good performance (material grains)
      • Material current disk AW-2219 (T851), previous successful Samples AW-6082 T6
    • Actions:
      • Manual polishing improved signal quality, but not significantly.
      • New disks will be produced with AW-6082 T6 (VDL)
      • Production 4 disks, 8 Weeks delay, 5000e order this week
      • Laser engraving postponed
    • New possibilities:
      • Glass ring grazing on aluminium disk is being considered
      • Information is being gathered, temperature constraints.
  • Scintillator assembly:
    • No spare components, no 2d/3d drawings available
    • Model remade 80% design optimization considering commercial components
    • Filter wheels commercial components need to be defined for design finalization.
    • Filter wheels are used in all machines with same design:
      • Required to produce spares
      • Agreed to produce 1 per machine + for new acquisition prototype.
      • A total production of 10 filter wheels was agreed.
2.2 Electronics and controls (J.Emery)
  • Systems:
    • DSpace lab system:
      • Ready for SPS and PSB scanner tests
    • Custom FPGA systems for SPS:
      • 1 system BA5 Ready test
      • 1 system 865 Ready installation
      • 1 system for FW development
    • Analog signals from Optical sensors available (scope)
  • Ongoing Developments:
    • New inverter board (P. Andersson)
    • FPGA FW is being modified for PSB (minor changes) (J. Emery)
    • Intelligent drive <--> VFC board communication (C.Vulliez)
    • 4 new control systems for next year VFC V2 based (to see availability).
  • Assembly requirements:
    • Fork must be aligned to motor N pole as SPS, resolver must rotate.
    • For electrical feedthrough, time required with the scanner to develop procedure.
  • Cabling:
    • Request for PSB and PS planned to be pull this YETS.
    • New surface racks will be installed on PSB.
2.3 Acquisition chain (J.L. Sirvent)
  • Scintillators assembly Set-Up:
    • Squared Scintillators available.
    • Cylindrical scintillators ordered and coming.
    • Mechanical housing being designed.
    • MaPMT ordered
    • All components available on 1st November for assembly
  • Filter Wheel Status:
    • Currently used Transmission coefficients --> 20%, 5%, 2%, 0.5%, 0.2%, Cardboard, Metal
    • Usage of commercial components (Thorlabs) for filter holders and fixation on disk (Threaded)
    • Proposed the usage of 25mm diam filters (smaller than 30mm currently used)
    • Requested to stick to 30mm, further search in providers required.
    • Proposed to procure 3 complete sets (2 for PSB + 1 for laboratory).
  • Acquisition system requirements for PSB (as SPS BA5):
    • PC + 2 PicoScopes
    • 1 VME HV power supply with remote control
    • 2 Filter Wheel controllers
    • 3 Units (Europa Crate) for Back-End prototype
    • Access to turn clock for data tagging.
  • Laboratory PMT tests campaign being prepared:
    • Instrumentation ready for tests
    • To check filters
    • Waiting MaPMT, but can tests with Sune's PMTs
    • Still to define testing protocol.
  • SPS News:
    • Big noise observed on PMT cable (synchronous with the beam), not so big on pCVD Diamond line
    • Amplifier box considered the possible cause
    • Access on SPS during Stop to remove amplifier box and attach directly the CK50 cable (Signal looks better now).
    • New Matlab-Based Expert application for Acquisition system (now tests are easier).

3. First look at milestones for the series: (R.Veness)

  • PSB Prototype installation in EYETS (End 2016)
  • PS Prototype installation (end 2017)
    • Location 54, A scanner will be removed to leave place.
  • Large series for production envisaged (2019-2020):
    • Proposed numbers --> 8 PSB, 5 PS, 5 SPS + spares
    • Need to agree on numbers (maybe 6 for SPS "H/V")
  • Take into consideration the work load for next years
    • Consider the request manpower, lab space...etc.
    • Single tender procurement needs to be justified or market survey done for very expensive parts.
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