Cylinder segment surface

[armin-ilg]

BEGINRELEASENOTES

• DDRec::VolSurface: Adding the capability to be only a segment of a cylinder <2π needed for ultra-light curved vertex concept.
  ENDRELEASENOTES

Hi everyone

I'm trying to make the ultra-light vertex detector concept working in full simulation, using k4geo from this PR. As a first step I added the functionality to VolCylinder to feature less than 2π circumference, changing the getLines function. Is there something else needed? Have in the past cylindrical sensitive surfaces actually been used in reconstruction?

Thank you,
Armin

Sensitive surfaces example:

[andresailer]

I converted this to a draft, until the whole chain is confirmed to be fully working.

[gaede]

Hi Armin,
I believe that adopting the getLines() as you have done should be all that is needed for Cylinders <2pi as the 'boundary' of the surface is handled by the volume. We use cylindrical surfaces for tracking in the ILD TPC, see e.g.:
https://github.com/iLCSoft/DDKalTest/blob/master/src/DDCylinderMeasLayer.cc
https://github.com/key4hep/k4geo/blob/main/detector/tracker/TPC10_geo.cpp
Cheers, Frank.

[github-actions]

Test Results

   18 files     18 suites   6h 26m 29s ⏱️
  374 tests   374 ✅ 0 💤 0 ❌
3 296 runs  3 296 ✅ 0 💤 0 ❌

Results for commit 3c06bf5.

♻️ This comment has been updated with latest results.

[MarkusFrankATcernch]

@armin-ilg Is this PR still relevant ? Or can it be closed without merge otherwise?

[armin-ilg]

@armin-ilg Is this PR still relevant ? Or can it be closed without merge otherwise?

Hi @MarkusFrankATcernch . No it can be closed without merge. Even with cylinder surfaces, conformal tracking would still need to be adapted to work with that. Instead, I've come up with the solution of representing curved sensors by trapezoidal volumes with flat surfaces, which works with conformal tracking (see key4hep/k4geo#557).

Sorry for not coming back to this earlier.