CLD_o2_v07: Fix lumi cal back shield, change envelopes to assemblies

[andresailer]

BEGINRELEASENOTES

• CLD_o2_v07: change LumiCal envelopes from boolean of boolean to assembly, fixes Geant4 complaints about LumiCalBackShield (CLD) #306, speeds up overlap check (of LumiCal only) with /geometry/test/resolution 300000 down to 13s instead of 3m10s

ENDRELEASENOTES

[Zehvogel]

LGTM 👍

I wonder what the point of the intersections was? Were they necessary to be put into the union?

[andresailer]

I wonder what the point of the intersections was? Were they necessary to be put into the union?

I was asking myself the same thing, of why using bool of bool instead of assembly.
Unions are supposed to be "well overlapping", so doing an union of just the tubes was giving an exception.

[atolosadelgado]

I have run a quick simulation with geantinos, it seems to stay in the same place within 10 um tolerance, so it is ok for me :)

[Zehvogel]

I have run a quick simulation with geantinos, it seems to stay in the same place within 10 um tolerance, so it is ok for me :)

It should not move at all :)
given the order of changes that we did in the past to the LumiCal, a tolerance of 10 microns seems a bit rough?

[atolosadelgado]

I have run a quick simulation with geantinos, it seems to stay in the same place within 10 um tolerance, so it is ok for me :)

It should not move at all :) given the order of changes that we did in the past to the LumiCal, a tolerance of 10 microns seems a bit rough?

sorry, my mistake, I have checked again at actually stays in place!