From 83d30686c07a5161eff77fcdfb9f37df5e828f7d Mon Sep 17 00:00:00 2001 From: Sandro Wenzel Date: Tue, 29 Sep 2026 11:13:20 +0200 Subject: [PATCH] Restrict the TRD PAI model to 14 particle species Reduce the Geant4 initialisation time by setting up the PAI model only for the charged species that matter in the TRD gas, instead of all 99. This reduces the PAI setup from 0.81 s to 0.11 s per o2-sim worker. | | all (99) | 14 species | |---------------------------------------------|-------------------|------------| | PAI model instances | 99 | 14 | | PAI setup time | 809 ms | 113 ms | | boxgen, 1 event: hits / steps | 14986 / 17871 | identical | | 5 pythia8pp events: hits / steps | 456275 / 530601 | identical | | 5 pythia8pp events: TRD hits / total charge | 69847 / 2.42322e6 | identical | Co-Authored-By: Claude Opus 5.5 --- Detectors/gconfig/g4config.in | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Detectors/gconfig/g4config.in b/Detectors/gconfig/g4config.in index 280489d754ed0..cd61afd493560 100644 --- a/Detectors/gconfig/g4config.in +++ b/Detectors/gconfig/g4config.in @@ -32,7 +32,7 @@ # Geant4 VMC >= v3.2 /mcPhysics/emModel/setEmModel PAI /mcPhysics/emModel/setRegions TRD_Gas-mix -/mcPhysics/emModel/setParticles all +/mcPhysics/emModel/setParticles e- e+ mu- mu+ pi- pi+ kaon- kaon+ proton anti_proton deuteron triton He3 alpha /mcPrimaryGenerator/skipUnknownParticles true # don't crash when seeing unknown ion etc. (issue warning) #