Emulating the Level-1 electromagnetic Trigger response using an Offline database. Procedure for populating this database from the Online information

Abstract

The Level-1 Trigger plays a major role in the CMS experiment allowing the reduction of the raw event rate at the Large Hadron Collider. Its decision is based on information from the electromagnetic and hadronic calorimeters as well as the muon detectors. The electronics of the electromagnetic calorimeter generate and deliver basic quantities called “Trigger Primitives” which correspond to local energy deposits created by electromagnetic showers. In order to ensure the correct generation of the trigger primitives by the electronics, special software called an emulator has been implemented. It is able to reproduce the ECAL trigger functionalities at the bit level using the same inputs and identical output format. It is configured in exactly the same way as the hardware. The configuration of the electromagnetic hardware trigger requires 5 million parameters stored into an Online Master Data Storage (OMDS) database. This paper will present the procedure used to transfer the parameters from the OMDS to the Offline database, which is used to perform the validation test with the Level-1 Trigger emulator.