Preliminary Design Review of the DUNE FD2-VD Charge Readout Plane (CRP) System
Review Information
Review Home
Charge Letter
7:30 AM → 8:00 AM
CRP detector system overview¶30m
Speaker: Dominique Duchesneau (LAPP, CNRS-IN2P3) CRPoverview-PDR-290322-v4.pdf
Srini: Could you comment on recommendations you have not met that came out of the CDR? For example the physics simulations of the strip width.
Answer: It is not covered yet and is now with the simulation group.
Bo: We had some exchange with Shanshan and other members from the BNL team and there is some work on the analysis but no formal result yet.
Mary: Clarification this is the question of strip width – not pitch. I assume there is some discussion at the LBNC meeting on the simulations that we could consult.
8:00 AM → 9:00 AM
CRP design status¶1h
Perforated anode , adapter boards and interconnection system¶30m
Speaker: Bo Yu (Brookhaven National Lab) CRP_Anode_Design.pptx
Sandro: Slide 8 – there are bridges between the strips?
Answer: The CRUs are independent no electrical connections between them. We don’t need to bridge the collection. We bridge the inductions at this location.
Sandro: Slide 10 in order to make the contact some of the holes of the perforations are removed? Does it generate a non-uniform edge response due to the loss of ionization charge
Answer: Yes, there will be some inefficiency in this location – some slight shadowing at the 2mm scale along this gap – so 2mm out of ½ a meter.
Srini: Can you comment on the 3 vs 6 segments? You are still doing 6 segments for the PRotoTYpe – are you pursuing the 3 segments?
Answer: We found several companies in India and China that can do 1x6 with silver plating which is said is to be good enough for edge connectors. The company that can do 1x3 cannot do silver or gold plating only bare copper. The cost is also somewhat tight. The decision is we are building this round with 6 segments but hoping in the long term we can cultivate the 3 segment issue.
Srini: Does the 6 segment meet your flatness and mechanical requirements?
Answer: Mechanically the flatness was okay for the prototype but there was some height variation. The main issue with 6 segment is the manpower to glue more segments – not the overall quality of the product. For getting the 3 piece it is a cost issue and without the plating we are not sure we want to do it – there is 2 years in between assembly and install and we worry about copper oxidation, so plating of the larger segments is critical to adopt the 3 segment.
Mechanical structure¶30m
Speaker: Benjamin AIMARD (LAPP) 2022-03-29_CRP_DESIGN
Terry: You have put the ground planes below the composite plate? What is the ground plate connected to? How is it connected to system ground?
Answer: This will allow to have a common ground reference to all the cold boxes. Instead of the copper braid attached to the back of the cold boxes. This copper layer will replace the braids. Will be covered later.
Kyle: Are there plans for mechanical fastners or strictly relying on the mechanical fastners on slide 11 and 21?
Answer: On slide 21 these were the rivets for CRP1. For the new CRPS we are only planning the screws shown on Slide 11. On slide 16 there is not a lot of stresses that separate the half plates. So these are the only fastners on slide 11 and glue.
Matt: On slide 7 you show spacers to separate the two PCBs? Is there more information on those spacers and how they are distributed and the tolerances?
Answer: Page 6 shows the positioning of the spacers. It is inserted in the anode – we don’t have special lateral tolerances of the spacer since that is provided by the anode. Vertically everything is machined.
Matt: What is the relationship between the edge board and the spacers?
Ian: Slide 7 on the spacers – what are the thoughts on thermal contraction on these spacers – does the peak contract more than the rest does this stay tight? Like the light green bushing.
Answer: We are using nylon for the bushing, on the vertical dimension the differential contraction is very low. On the diameter you lose a few 1/100's mm of the diam. On the vertical it is on the order 10's of mm. Everything is in plastic material so when we tigthen everything there is a degree of elasticity on those connections. We have tested and we had no problem for 3 cooling and warming cycles.
Sandro: These modules will be tested in the cold box and Module 0? Is there a plan to test the full size validation of the design for a full size super module in the cold?
Answer: We will discuss tomorrow the design talks on the superstructure. The composite and full scale composite are being tested in the cold for the CRP. For the superstructure we are planning to test it warm and then see if it agrees with computations, but not possible to test the full size superstructure in the cold.
Jack: Are there an 2-D drawings of the superstructures? I see only models in the documentation and the step files. I am looking for the 2-D drawings for everything to see how everything lines up.
Answer: We have some 2-D drawings for the spacers, we can discuss offline to see which drawings you need.
9:00 AM → 9:30 AM
CRP Assembly Process. Anode preparation, QC and production¶30m
Speaker: Serhan Tufanli (CERN) CRP_PDR_March2022_CRP_production.pdf
Srini: Do you have a QA/QC document that list all the tests that need to be done at every stage from receiving the components to final production?
Answer: I have an assembly document that includes the QA/QC steps at each stage fo the assembly
Kyle: Slide 19: Is it known where the factories are which will complete the assembly? So the lower right hand corner is what
Answer:
Srini: Is there a plan to put together the CRPS in all the 4 factories before the FDR?
Answer: We are working with CERN, Grenoble and other sites in Europe currently. In addition, CRP #3 and 4 will be assembled in the US and shipped to CERN for Module 0.
Dominque: The question is what will be done for the FDR which is when?
[Mary in chat: Expected for November 2022]
9:30 AM → 10:10 AM
CRP Factories¶40m
Top CRP assembly in Europe¶20m
Speaker: Jean-François Muraz (CNRS/IN2P3/LPSC) TOP_DUNE_CRP_ASSEMBLY_IN_EUROPE_PDR-3.pdf
Srini: Tooling: you kept mentioning that LPLC is designing the tooling? Is this the same for all factories or is US doing it separate? What is the timescale for the tooling?
Answer: European factories will be ready 1 year before the US ones. The other factories can reuse our design if they find this useful.
Srini: Slide 8: You have 2 hrs for testing – you have to look at spacing, mechanical and electrical – is two hrs sufficient – is one technician enough?
Answer: This is only an electrical test – we will not do mechanical testing – not at this stages – this will be done during the assembly, at this stage we are only testing continuity and HV tests.
Dominique: The spacing between the PCBs if they are done properly will not need to be retested/requalified
Jack: I saw a reference to a clean room during the assembly process – what is the quality of the clean room? Is there any expectations of clean space after production? Is there expectation for a clean room specification underground? Or is it just a gray room?
Answer: Only a gray room is expected.
Jim M: Slide 7: it is mentioned non-conformance management? Is there a non-conformance report that is produced and approved before you proceed?
Answer: Here we want to feedback – say nonconformance on the silver plating and send it back to the factory
10:30 AM → 11:00 AM
Break 30m
11:00 AM → 11:30 AM
Executive session¶30m
10:10 AM → 10:30 AM
General CRP production plan (schedule, transport)¶20m
Speaker: Dominique Duchesneau (LAPP, CNRS-IN2P3) CRP-productionPlan-PDR-290322.pdf
Srini: So you plan to have produciton in 2024 so a PRR by end of 2023?
Answer: Yes
Srini: Are you confident your plan is sufficient to take you to the FDR?
Answer: We need to focus our schedule on getting ready for Module 0 so we can be ready for the FDR
11:30 AM → 12:10 PM
First CRP and coldbox tests¶40m
CRP1 and lessons learned from TDE studies for next CRP¶15mp
Speaker: Dario Autiero (IPNL) CRP1_TDE_PDR.pdf
Terri: The steel structure for the CRP and the copper plate now added to the bottom of the composite frame – what are the ground connections for those two.
Answer: For the bottom electronics the noise was fixed by connecting the boxes with grounding braids and this copper plate fixes this problem. For the top electronics we have to figure out how to use this layer. The steel structure was grounded to the cold box ground. For the additional copper layer for the top electronics we are considering either connecting it to the steel structure or leaving it floating. For the cold box it is one ground braid connected to the side of the steel structure to the cold box.
Matt: Page 5: I don’t understand why for the event you pointed out why the track becomes so faint in the bottom right hand plot.
Answer: This is not a track coming from the LAr, this cosmic ray is actually in the gas coming from top of the CRP where you still collect some ionization that shows up as a ghost in the LAr.
CRP1 and lessons learned from BDE studies for next CRP¶15m
Speaker: Roger Huang (Lawrence Berkeley National Laboratory) CRP_BDELessons_PDR.pdf
Terri: Where are the grounding connections to the grounding plane? Where are the dielectrics?
Answer: I don’t have
CRP1 perfomance and results¶20m
Speaker: Laura Zambelli (LAPP - CNRS) pdr_review_CRP1_performances.pdf
8:00 AM → 9:25 AM
FD2 CRP integration in cryostat¶1h 25m
Top CRP superstructures design and integration¶30m
Speaker: Nicolas GEFFROY (LAPP - CNRS)
2022-03-30_PDR_SST_Integration_in_Cryostat.pdf
Mike Andrews: On the design of the platform, the railing is very short – there has to be some safety harness to allow work as shown
Answer: There is a lifeline and it is indicated in some of the drawings. We will follow all OSHA standards.
Duane: We also need to understand how we get them off the platform in case of emergency, incapacity..etc. The evacuation plan.
Answer: Slide 54: everything will be done by two walkers – if there is a problem we will lower the entire superstructure, we will remove the pins 3 pins and we can lower it very fast – 20 seconds from the top of the cryostat to the bottom. And then we can proceed to the bottom of the cryostat and egress.
Kyle: In the scenario described is it possible there are cables routed already between the anode and the feedthrough which would prevent the platform from being lowered?
Answer: We would go fast and sacrifice the cables and the connectors will break.
Duane: You need to make sure they will break cleanly and not prevent
Answer: We have two types of connectors under consideration – ones with clips and one without.
Mike Andrews: You have a very good start to the plan – I do appreciate the detail given today and we will work more on this.
Superstructure Finite Element Analysis¶25m
Speaker: Guillaume Deleglise (LAPP-CNRS)
2022-03-30_Vertical_Drift_FEM_for_PDR.pptx
Duane: Thank you for the details - we will stay in touch about the design.
Answer: This type of equipment we have used for other projects here in Europe and we are trained to use them and are very familiar. We need to adapt to US standards but the philosophy and the type of materials are very similar.
Bottom CRP support structure design and integration¶30m
Speaker: Ian Jentz
03-30-2022_PDR_BottomSupports.pptx
Jim Stewart: Slide 20 they don’t fit in the Ross shaft other than vertically. So does this get rotated in the hall or outside the hall? Installing will be a bit blind and also installing the last ones will need a different procedures – we will need to work out these procedures before the I&I PDR in June.
Answer: We expect to use the same box as the top anodes which will not have the feet that get in the way. It will probably be swung vertically outside the hall (needs to be verified)
Kyle: Question of the deflection of the bottom CRP composite frame – is there a 6 support configuration still on the table?
Answer: The 6 support configuration is out to allow for cabling – we took it out to four (slide 15) and increased the size of the support somewhat
Sandro: How stable is the bottom membrane of the cryostat – is there something there to take the weight of the CRP?
Answer: Part of why we are doing this installation support structure – the membrane floor bubbles up if there is no weight – only with weight on it will it go where it is supposed to be. We can press the floor down with the weight of this structure to where it is level and then we can install level wrt to the floor
Matt: Slide 16 – does the corrugation have some symmetry? How well defined is the pattern of corrugation defined and do you need fixed pieces or adjustable to match the membrance floor grid?
Answer: The membrane floor grid is not exactly symmetric around the center axis – different panels are used and they are not in a perfect grid panel. The CRP anode plane is very symmetric. Because of cabling are shifted somewhat down and over off-axis. If the membrane floor layout changes, this approach will still hold it will just land slightly differently.
Jack: The membrane floor is fixed and the drawings from GTT are there already.
Jack: Slide 6 – it looks like there is a lot of hardware for a very flexible design – please simplicity and minimize hardware – we have to tighten 6 screws for every one of these – we want to avoid loose hardware in the cryostat. This system is overly complicated for what it needs to do.
Jim: As the lifting points are not yet defined on the CRP – are you going to redo the FEA on the CRP once the lifting points are defined? Do you have enough labor to support that?
Answer: We presented yesterday the deformation with 6 feet instead of 4, it will be easy to redo with 4. Benjamin will update it.
9:25 AM → 10:25 AM
Interfaces CRP with HV, TDE, BDE, Calci, JTCom, facilities¶1h
Speaker: Serhan Tufanli (CERN)
CRP interfaces overview¶30m
Speaker: Serhan Tufanli (CERN)
CRP_PDR_interfaces_overview.pdf
BDE integration¶15m
Speaker: Manhong Zhao (BNL)
Kyle: The patch panel are responsibility of the BDE consortia – what is the schedule to finalize the design and the corresponding CRP composite support structure?
Answer: We are co-ordinating with the BDE consortia and they hope to finalize the patch panel design very soon.
10:25 AM → 10:40 AM
Break 15m
10:40 AM → 11:35 AM
CRP prototyping activities plan¶55m
50L anode setup tests¶20m
Speaker: Serhan Tufanli (CERN)
Sandro: What are the capacitor modifications?
Matt: Do you have the S:N for the 3rd run? Do you expect different S:N?
Answer: Still doing analysis for 3rd run don’t expect S:N differences
CRPs in 2022¶20m
Speaker: Dominique Duchesneau (LAPP, CNRS-IN2P3)
CRP-prototyping2022-PDR-290322v2.pdf
Sandro: CRP 5 will also be tested in the coldbox?
Answer: Not clearly defined yes – CRP3 and after should be tested in the cold in the US. There is no schedule for testing in the CERN coldbox.
Sandro: Does the testing in the cold include the conformity for readout in the cold in the US tests? Is it a bath?
Answer: The tests at BNL use a bath, the tests at the factories is yet to be determined – for both cold tests it will include readout.
Mary and Srini: Trying to understand how CRP3, 4 and 5 will be used to influence the final design given that CRP4 and 5 and even 3 testing in the cold box may not be ready for the FDR later 2022.
Answer: CRP 2 is sufficient to develop the final design.
Srini: Is there a plan to demonstrate the 3 panel design before the PRR? If the 6 segment design meets requirements is it not sufficient to be the baseline design for FD2?
Answer: The tight schedule for module 0 the priority will be on the 6 panel design. The work is ongoing for the 3 panel R&D. The main difference for 3 vs 6 panel the structure design and connections will not change – it will just be faster.
Kevin: Is there a QA procedure and assembly instructions ready for the prototypes you are planning.
Answer: For CRP 3 and 4 we already have an assembly procedure based on CRP #1 experience which includes QA tests. We will create a separate QA document and at the end of CRP#2 we expect QA and assembly procedures to be ready for CRP 3 and 4
Matt: There was a comment that the biasing was changed from CRP#1 for CRP 1b to accommodate the BDE. Which of those changes have been implemented in CR1b and which is still on the fly?
Answer: Additional capacitors and small filter boards are installed on CR1b to deal with the BDE noise - the additional filtration is now included in the design for CRP2 and later.
Module-0 Prototype program¶15m
Speaker: Filippo Resnati (CERN)