Status of J-PARC after the Great East Japan Earthquake

Abstract

J-PARC was heavily affected by the March 11 Great East Japan Earthquake. When the earthquake struck, we had a beam study operation of the linac and the machine immediately stopped. We can see subsidence at many places; about 1.5 m over the wide area at the entrance of the linac building, about 50 cm over the area of 1 m×10 m at the main ring building, etc. Underground water is coming into the linac and the main ring tunnels. The water level at the linac reached a depth of 10 cm, but pumping with a diesel generator successfully saved from further flooding. At the RCS, the circulating road went wavy and the yard area for electricity and water devices was heavily distorted. The current status of the J-PARC accelerators after the earthquake is reported.