Minutes BWS Upgrade: Electro-Mechanical Design Meeting #12 -- 13th July 2016 --
Participants: Raymond Veness, Bernd Dehning, Federico Roncarolo, Jonathan Emery, Patrik Andersson, Jose Luis Sirvent
Agenda ( https://indico.cern.ch/event/543918/
)
1. Communications (R.Veness)
- PSB ECR already launched and progressing on the aproval
- Forks 2-3 units are out of tolerances. The work has to be redone, which would delay the pieces availability to end of August.
- For mounting test (on august) 1 of these fork will be modiffied to fix the tolerances with some bricolage.
- The error comes from a perpendicularity deviation Shaft-Fork.
- The assembly test will be performed in August and the device plans to be available for functional testing on September.
2. Alxion Standard and Special Motor testing (J. Emery)
- Tested Alxion Standard and Special version with modiffied airgap (300V)
- Back-EMF normal version: Show nice results and 1% deviation respect to specs
- Back-EMF special version: Show also nice reults with 4% deviation respect to "estimated" specs.
- Not clear if special version was tested by Alxion before procuring specifications or they approximated by calculations
- Speed and profiles tests with Special Alxion show satisfactory results with Dspace, calculated torke ~ real required torke
- Problem found after motor testing:
- Appeared after the week-end (test finished Friday, problem appeared Monday)
- Motor generates a extrange noise even when not moving and holding position
- Effect is not symetrical, appears in In & Out Scans but seems stronger in Out scans.
- Currently trying to work out the reason:
- During movement the currents are showing a extrange behaviour
- Motor dismounted, visual inspection (Dmitry) show no frictions
- Isolation on phases seems not to be the problem, tests show that they're ok.
- Cross-Check wiht Parker motor--> No problem seen
- Test with older compiled code --> Problem still seen
- Generator Mode --> the output voltages are Ok
- Next steps:
- Try standar Alxion
- Try another Alxion stator 300v
- try standar rotor.
- For the moment the reason still unclear.
3. PSB Acquisition system: Intallation proposal (J.L. Sirvent)
- Installation requirements: 1 Functional system (PSB standard) + 1 Test flexible test platform (Independent systems)
- Base line is acquisition on surface , both options send their analog signals to surface
- In PSB short cables & long bunches --> Fine for BW point of view (bunch pile-up)
- Gain in noise reduction << Risk of failure of acquisition Front-End for radiation exposure
- In any case allow installation of a Front-End for testing pourposes
- The idea is to procure a operational (PSB) system 100% available for functional validation
- Allow space & cabling flexibility to test different scintillator + photo-detector configurations
- Standard Cylindrical 30x30mm
- New Rectangular 100x100x10mm
- MaPMT, HPD, Filterweels
- Space reservation for 1 Front-End
- 3 Set-up Configuratoins show using the same cabling requirements.
- High dynamic range acquisition system (no required filter / pmt gain tuning)
- Strategy 1. HPD + QIE10/12 (1e5)
- Stregety 2. MaPMT + ICECAL (1e5)
- Stragety 3. MaPMT + 2 x QIE10/12 (1e7?)
- New mechanics required to procure for both assembies:
- FilterWeels
- PMT/MaPMT/HPD shielding
- Scintillator/Waveghides holder
- Supports
- All these details are not included on ECR
- Studies on PSB needed to:
- Estimate required dynamic range on PSB
- Adjust acquisition systems working point
- Cross-Check PSB simulations
- Check possible improvements by changing Scintillator Geometry
- Check Light yields on scintillator per impacting proton on wire (for different energies/intensities)
- Proposed ways to proceed:
- Trust on simulations ? Check with Roberto Rocca.
- Estimate light yield trough measurements stored on measurements DB
- Prepare measurement campaign new systems when installed.
4. Comments from Dundee Visit (R.Veness)
- Some issues were identiffied thanks to the visit
- Residual material observed on measurements:
- It reduced the reflectivity on some disk areas
- Comes from some abrasive liquid used for finishing the laser slits.
- Smooth transition Reflective/Non Reflective
- Such smotth transition did not allow enought "flat" reflective area between slits
- Sample and laser are in a fix position, Laser scans the disk by angular movements
- Laser loses focal point, which produces wider slits
- For Dundee Equipment, 20 um width slits was already on the limit (we asked for 10um slits)
- The fabrication of full size disk would produce worst slits due to equipment configuration
- Dundee required XY Stage + Controller system (and maybe new laser) to produce high quality slits.
- Estimated Cost > 10KCHF
- In collaboration with other sections and other uses foreseen, if required cost may be splitted by 3.
- Jose's remarks:
- With commercial company we reach the results required for the slits.
- Does it worth it? we'd need a guarantee that this new equipment would produce better slits than commercial.
- In any case, the sensor weak point is the surface quality (roughness, defects, reflectivity)
- Instead of spending time/money in building very spensive disk it may worth it to improve the sensor robustness with some minor mofifications for metallic disks usage (more scaning dots / different configuration).
Topic revision: r1 - 2016-07-14
- unknown