A SEQUENCER FOR THE LHC ERA

The Sequencer is a high level software application that helps operators and physicists to commission and control the LHC. It is an important operational tool for the LHC and a core part of the control system that interacts with all LHC sub-systems. This paper describes the architecture and design of the sequencer and illustrates some innovative parts of the implementation, based on modern Java technology. ARCHITECTURE AND DESIGN The sequencer tool is conceptually divided into two parts: the sequencer, i.e. the software system capable of running sequences, and the sequences themselves. Architecture and Design of the Sequencer The sequencer follows the same architecture and technology as most of the accelerator controls software: a 3-tier architecture implemented in Java using the Spring Framework [1]. This architecture is shown in Figure 1.