Consider adopting non-cylindrical tracking region in IDEA and ALLEGRO to suppress Lumical secondaries

[atolosadelgado]

Dear experts,

The FCCee CLD detector currently uses a non-cylindrical tracking region to avoid saving secondaries generated in the Lumical into the output file:

k4geo/FCCee/CLD/compact/CLD_o2_v07/CLD_o2_v07.xml

Lines 265 to 274 in 351ae69

	<parallelworld_volume name="tracking_volume" anchor="/world" material="Air" connected="false"
	vis="VisibleBlue">
	<shape type="Polycone" material="Air">
	<!-- small-angle approximation for tan(theta) -->
	<zplane z="-OuterTracker_half_length" rmin="149*mrad * ConeBeamPipe_zmax" rmax="OuterTracker_outer_radius" />
	<zplane z="-CentralBeamPipe_zmax" rmin="0" rmax="OuterTracker_outer_radius" />
	<zplane z="+CentralBeamPipe_zmax" rmin="0" rmax="OuterTracker_outer_radius" />
	<zplane z="+OuterTracker_half_length" rmin="149*mrad * ConeBeamPipe_zmax" rmax="OuterTracker_outer_radius" />
	</shape>
	</parallelworld_volume>

Would it be worth considering a similar feature for IDEA and ALLEGRO detectors?

Thank you very much for your time and insights.

Best,
Alvaro