Online Beam Spot in High Level Trigger

Introduction

Several ATLAS High Level Trigger (HLT) algorithms require precise knowledge of the LHC beam interaction point information. In the case of the b-quark tagging algorithm to identify secondary decay vertices or tracks, the knowledge of the beam line is critical. In addition, the measurement of the beam spot profile online with fast updates is of great help to the LHC accelerator commissioning which in turn helps the luminosity delivery to ATLAS. However, the implementation of this in the ATLAS HLT has various technical challenges associated with executing this monitoring in thousands of online processes. A detailed description and status of this project can be found at the  AtlasTriggerBeamSpot wiki page. SLAC bears the main responsibility of the project and David Miller (Stanford student) is coding one of the two algorthms.      

Project Tasks

 There are various technical issues and validation where more students can contribute, such as: 

• Configuration and testing of the multi-node gathering of the `express collection' of histograms for performance and integrity.
• Validation of algorithm robustness (e.g. against misalignment).
• Validation of beam spot redistribution.   

Su Dong & Rainer Bartoldus

Last modified:  Sun May 4 23:52:06 PDT 2008