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BTOF demonstrator/mechanics meeting
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US/Pacific
Description
https://ucsc.zoom.us/j/98299273347?pwd=HHm9tGM6hD7aZaIVWWaF16ueAT3gVu.1
Quick recap
The meeting focused on resolving design specifications for the TOF (Time of Flight) stave placement and service hybrid integration. The team discussed the exact dimensions of the stave envelope, confirming it as 267.5 centimeters total length with 7.5 centimeters (mm?) thickness, and clarified that the service hybrid would require 160mm x 60mm x 15mm of space. Key decisions included removing the last stavelet and replacing it with the service hybrid, creating approximately 5 centimeters of unused space on each side. The group also reviewed FPC (Flexible Printed Circuit) routing designs presented by Takashi, with Tonko suggesting to maintain the original fan-out proposal rather than implementing clock fanouts. Temperature monitoring requirements were discussed, with agreement to include one temperature sensor per sensor rather than per stavelet. The team emphasized the need for precise drawings and 3D models to ensure consistency across presentations before the upcoming review.
Next steps
- Andy: Create and share a 3D model of the stave according to the agreed envelope and dimensions, including correct distances and clearances, for review and further detailing by the team.
- Wei (and relevant electronics team): Investigate the possibility of reducing the size of the service hybrid/power board and connection scheme, especially regarding FPC routing and connector space, and report back on feasibility.
- All (led by Andy and electronics team): Coordinate to populate the 3D stave model with electronics, sensors, and service hybrid, using correct step files and dimensions, to ensure compatibility with the overall detector envelope.
- Satoshi: Update the presentation and drawings to reflect the new baseline design (removal of the last full stavelet and inclusion of the service hybrid in the correct location), and clarify the use of the updated ASIC design for the upcoming review.
- Andy (with postdoc support): Continue work on completing the CATIA model for the TOF and its support structures, and share progress with the team.
- Team (Tonko, Andy, Zhangbu, Satoshi, Wei): Review and agree on a single baseline mechanical and electrical layout for the stave/service hybrid, including handling of unused space and stavelet length, and document for the review.
- Team: Create and share a correct drawing (ideally 3D) with all relevant distances and clearances marked for final verification of the mechanical design.
Summary
Service Hybrid Component Space Requirements
The team discussed stave placement and space requirements for the service hybrid component. Wei explained that the service hybrid would require 160 millimeters by 60 millimeters by 15 millimeters in space due to the need for separate power lines, linear converters, and signal connections. While there was a suggestion to potentially reduce the space by a quarter, Wei indicated they preferred to design with a confirmed working size rather than risk limitations.
Carbon Fiber Manifold Dimensions Discrepancy
The team discussed discrepancies in the dimensions of the carbon fiber cooling manifold, with conflicting numbers being mentioned for the total length (ranging from 267.5 to 289 centimeters). Tonko raised concerns about the definition of the envelope and the space required for cooling pipe bending, which he estimated could require an additional 5 centimeters in the Z direction. Andy clarified that the total length is 267 centimeters and explained that back-bending of the cooling pipes is not possible due to thermal constraints, requiring the pipes to enter from both sides.
Carbon Fiber Stave Design Specifications
The team discussed the dimensions and design specifications for a carbon fiber stave used in a TOF (Time Of Flight) system. Andy clarified that the total available space for the stave is 267.5 centimeters, with each stave being approximately 133 centimeters in length when split into two symmetric pieces. The team confirmed that the cooling pipe is embedded within the carbon fiber structure and runs in a loop on the inside. Zhangbu noted that there was a discrepancy between the preliminary design report's specifications and the current design, with the actual envelope being 267.5 cm rather than the reported 288 cm.
Cooling System Design Discussion
The team discussed the design of a cooling system with separate staves, confirming that there is a 2mm gap between them. Andy explained that previous attempts to run the cooling pipe through the entire system were abandoned due to cooling power limitations and potential leaks. The group reviewed the size requirements for the service hybrid, which needs to be 160mm x 60mm x 15mm to accommodate the power board on the cooling manifold, separate bias lines, and future connector requirements. Tonko expressed concerns about the 1.5cm height being too large, particularly when considering wire bonds, and suggested it may be impractical to place ASICs below the power board in the near term.
Cooling System Design Placement
The team discussed design considerations for a cooling system, focusing on the placement of heat-generating components relative to the cooling pipes. They determined that the power board, which generates three times more heat than the ASIC tablets, should be positioned to avoid heating the incoming cooling water. The group agreed that the highest heat load components should be placed on the output side of the cooling system rather than the input side to ensure effective cooling of temperature-sensitive components like the sensors.
Detector Space Allocation Discussion
The team discussed space allocation for detector envelopes and services in a technical design. Andy clarified that the green and red areas shown in the presentation represent existing service spaces, not additional available space for detectors. Dan explained that the blue rectangle represents the minimum space required to route services into proper trays, which cannot be used for detector space. The discussion concluded with confirmation that the green square area was already included in the current envelope design.
Detector Routing Design Mock-up Review
The team discussed a mock-up design for routing cables and services between detectors, with Dan explaining that the printed boxes represent the ends of detector envelopes rather than the full volume occupied. Dan clarified that the design alternates between TOF/Symbol and SVT services, with 12 TOF/Symbol channels and 10 SVT channels per sector. The discussion concluded with Satoshi raising a question about using updated ASIC designs, noting that the stave length had changed and they no longer needed to use half sensors, resulting in a stable link length of approximately 130 centimeters.
ASIC Design Updates Discussion
The team discussed updates to the ASIC design, with Simone Mazza confirming it was nearly approved and would be finalized by June 1st. They reviewed assembly drawings and considered modifications to the hybrid and FPC placement, with Tonko suggesting removing a tablet and replacing it with a service hybrid. Zhangbu proposed exploring options to potentially extend components to cover a larger area, though the specific implementation details remained under discussion.
Sensor Placement and FPC Design
The team discussed modifications to sensor placement and FPC (Flat Panel Connector) design. Tonko confirmed that the last four sensors would be removed, shortening the FPC correspondingly. The group identified 5 centimeters of unused space on each side of the design, though there was some confusion about the exact layout and symmetry of the components. Satoshi proposed adding two additional sensors in the available space, but the team agreed they needed accurate drawings and potentially a 3D model to properly determine the feasibility of this proposal, particularly considering factors like stave thickness due to oil.
Stave Model Design Updates
The team discussed updates to a stave model, with Andy planning to create a model based on envelope specifications that can be copied 244 times for the central cat drawers. Simone Mazza mentioned modifying the stave to include only two sensors instead of the original longer design to address assembly concerns and eliminate a crack issue. The team agreed to maintain consistency in their design baseline, with Zhangbu requesting weekly meetings before reviews to ensure alignment, and Simone Mazza noted he would be unavailable for next week's conference but would still call the meeting.
FPC Design and Routing Discussion
Takashi presented his FPC design assumptions and line routing approach, which included connecting clock and data lines one-by-one for each ASIC and placing temperature sensors on each sensor. Simone Mazza expressed concerns about using clock fanouts, preferring the original FPC proposal, and noted that FCFD 1.2 lacks fast command functionality. The group discussed the placement of temperature sensors, with Simone Mazza supporting one per sensor for benchmarking purposes, while Zhangbu questioned the necessity given the per-stave high voltage lines. The team agreed to maintain one temperature sensor per sensor and revisit the decision if issues arise during implementation.
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