抄録
At the J-PARC Main Ring synchrotron (MR), as the beam power is so high beyond a hundred kilowatts, a large increase of the vacuum pressure is observed during the beam acceleration periods. The change of the vacuum pressure has been recorded at the fixed point of the MR synchrotron ring for three years. The pressure growth normalized by the beam current was in inverse proportion to the total charge or the integrated beam current. The analysis shows the vacuum system is compatible with a future power-upgrade of the MR.
