ToF Simulation Meeting

Tuesday 5 Aug 2025, 10:00 → 11:30 US/Eastern

Zoom
https://cern.zoom.us/j/64362083814?pwd=UVJDSWljQTl6RFEzK25HTUpva2hLZz09

10:00 → 10:10 Intro

Speaker: Kentaro Kawade (Shinshu University)

List of urgent items discussed during the collaboration meeting.

1. What is the ultimate timing resolution needed?
Based on our simulation studies (where full digitization has not yet been implemented), we concluded that a total timing resolution of 44 ps satisfies the requirement by a narrow margin for the Barrel ToF.

This 44 ps includes contributions from:
- the sensor timing resolution,
- electrical jitters, and
- the finite T0 resolution.

A similar study for the fToF is currently underway and will be completed soon.

2. Does the  fToF contribute to the tracking, and if yes what requirements does this set?
The fToF is not designed as an ultra-thin detector;
It has a material budget of approximately 7%, which is already included in the GEANT4 simulation.
Although we have not conducted a dedicated study on its impact on the dRICH tracking performance, there are currently no concerns raised by the dRICH group.

Thus, we consider that the fToF does not contribute to the tracking performance of downstream detectors.

3. What is the allowed material budget not impacting the performance of the other detectors.
This is one of the most critical issues in the Barrel ToF design and will require negotiation with the TC.

Our simulation studies suggest that increasing the material budget from the initial concept (<1%) to 6–7% does not significantly degrade the tracking performance.

Specifically, the tracking resolution was found to worsen from 0.6 mrad to 0.7 mrad when the material budget is increased to 6–10%.
This change does not have a significant impact on the hpDIRC tracking performance.

Therefore, we believe that allowing a 6–7% material budget for the bToF is acceptable.
This budget is important for a realistic mechanical design, including support structures, coolant fluid, readout FPCs, and other components.

4. What is the acceptance needed for the physics, do small acceptance gaps between modules have a negative inpact
We have not yet conducted such a study.
To evaluate this, we will need to implement the acceptance gaps into the ePIC simulation.

10:10 → 10:20 Status from Kent/BNL/Stonybrook

Speakers: Chun Yuen Tsang (Kent State University), Prithwish Tribedy (BNL), Souvik Paul (staff@stonybrook.edu;student@stonybrook.edu)

10:20 → 10:30 Status from ITT Madras/IISER

Speaker: prabhat pujahari (Wayne State University)

10:30 → 10:40 Status from Hiroshima

Speaker: Satoshi Yano (Hiroshima University)

10:40 → 10:50 Status from Shinshu

Speaker: Kentaro Kawade (Shinshu University)

10:50 → 11:00 Round table and AOB

Speaker: Kentaro Kawade (Shinshu University)