External Resources: Clouds and HPCs for the expansion of the ATLAS production system at the Tokyo regional analysis center

The Tokyo regional analysis center at the International Center for Elementary Particle Physics, the University of Tokyo, is one of the Tier 2 sites for the ATLAS experiment in the Worldwide LHC Computing Grid. The current system has 10,752 CPU cores and 16 PB disk storage. CERN plans the high-luminosity LHC starting from 2026, which increases the peak luminosity to 5 times compared to the present value in LHC. For the high-luminosity LHC, a requirement of computing resources for each site will be increased. To expand the ATLAS production system at the Tokyo regional analysis center, R\&D using external resources has been launched. One kind of external resources is a commercial cloud resource, such as Google Cloud Platform. Another resource is the High-Performance Computer (HPC) at the University of Tokyo. In this paper, the current status of the R\&D, the systems for these resources and comparisons of the cost are reported.