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.
Topic revision: r1 - 2016-09-22
- unknown