On Sep 29, 2024, at 11:54 PM, Sourav Tarafdar stara@jlab.org wrote:
Dear Satoshi and Zhangbu,
Project is currently collecting information about QA for each subsystem of ePIC. So from ToF consortium may can you please provide a quick list of components associated with ToF that are subject to quality control ? As an example I suppose each of the sensor for ToF will first undergo some sort of QA before using it for final ToF. Same will be probably for ASICS and of course there will be more components of ToF which will first undergo Quality Control before being used for final ToF assembly. If you can provide us ONLY the list of those items in next two weeks that will helpful. Later (possibly before CD2 early next year) one has to write a detail documentation on QA for each ToF components.
Thanks,
Sourav
List:
QA long-term and stress-test reliability studies of LGADs as a stepping-stone towards studies on AC-LGADs
For both sensors and readout chips, it is imperative to evaluate the yield of the test productions to adjust the final production orders. The QA plans to evaluate the yield of the sensor productions are as follows: each produced sensor will be tested in the laboratory in a probe station with simple current over voltage (IV) and capacitance over voltage (CV) tests
To evaluate the yield of the chip (EICROC, FCFD) productions, a sample of chips from each batch will be tested and probed for homogeneity in all the channels using a calibration input. All channels have to be within required homogeneity.
Once the state of sensors, readout chips, and flex is advanced, a fully loaded demonstrator stave is envisioned. The mounting procedure will already be tested during the assembly of the thermomechanical demonstrator. The full demonstrator will then be tested with radioactive sources in laboratory or at test beams
Mock-up mechanic and cooling systems will be assembled for testing of installation procedures off-site.
construction and installation QA:
Only components that pass various quality inspections—such as visual checks, metrology, and electrical tests— proceed to the assembly stage. Upon completing the installation of sensors and ASIC on both sides of a stave, the final round of testing is conducted. Fully tested staves are then shipped to BNL for integration into the global support structure of the ePIC detector. For example, BTOF system contains 144 slots for precise alignment of the staves within the global coordinate system. For FTOF, assembly of the modules occurs in class-7 (or higher) clean rooms, while the PB and RB can be assembled under standard conditions. The modules undergo thorough quality checks after sensor-ASIC assembly before moving on to Service Hybrid assembly. After passing all connectivity and performance tests, the modules and SHs are shipped to BNL, where they are attached to the disk-shaped support structure.
Full-system test will have to be performed for electric connectivity and cooling leak before operation.
