he Application of SNiPER to the JUNO Simulation

he JUNO (Jiangmen Underground Neutrino Observatory) is a multipurposeneutrino experiment which is designed to determine neutrino mass hierarchy and preciselymeasure oscillation parameters. As one of the important systems, the JUNO o ine software isbeing developed using the SNiPER software. In this proceeding, we focus on the requirementsof JUNO simulation and present the working solution based on the SNiPER.The JUNO simulation framework is in charge of managing event data, detector geometriesand materials, physics processes, simulation truth information etc. It glues physics generator,detector simulation and electronics simulation modules together to achieve a full simulationchain. In the implementation of the framework, many attractive characteristics of the SNiPERhave been used, such as dynamic loading, exible ow control, multiple event management andPython binding. Furthermore, additional e orts have been made to make both detector andelectronics simulation exible enough to accommodate and optimize di erent detector designs.For the Geant4-based detector simulation, each sub-detector component is implemented asa SNiPER tool which is a dynamically loadable and con gurable plugin. So it is possible toselect the detector con guration at runtime. The framework provides the event loop to drive thedetector simulation and interacts with the Geant4 which is implemented as a passive service. Alllevels of user actions are wrapped into di erent customizable tools, so that user functions canbe easily extended by just adding new tools. The electronics simulation has been implementedby following an event driven scheme. The SNiPER task component is used to simulate dataprocessing steps in the electronics modules. The electronics and trigger are synchronized bytriggered events containing possible physics signals.The JUNO simulation software has been released and is being used by the JUNOcollaboration to do detector design optimization, event reconstruction algorithm developmentand physics sensitivity studies.