Geant4, Software toolkit to simulate the passage of particle through matter

Geant4 is a de fact standard for detector simulation for various application domains. We support Geant4 simulation not only for HEP experiments but other interdisciplinary applications, medicine, space, etc.

We develop software framework for particle therapy simulation as a medical application of Geant4. We released PTSim as a software framework for simulation of hadron therapy facilities, and gMocren that is 3D visualization tool for CT images. PTsim is used in different hadron therapy facilities, HIMAC, NCC, HIMBC, etc. The users spread not only in Japan but in other Asian countries. We release these software publicly in medical users and keep continuous efforts to improve software.

To improve simulation speed, we investigate various ways of parallelism in Geant4, using MPI (Message Passing Interface), Multi-thread, GPGPU (General Purpose computing on graphic processing units), etc.

The development and maintenance of Geant4 are organized under the Geant4 international collaboration. KEK Computing Research Center organizes Japanese activities of Geant4, and provides user supports like consultation, lectures, and workshops, etc.