• F. Naito, K. Nanmo, H. Tanaka
  KEK, Ibaraki
• H. Asano, T. Ito
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken

X-ray radiation from the SDTL of J-PARC linac has been observed with the beam loss monitor by the cavity. The results show that the X-ray intensity depends not only on the RF power level of the tank but also on the RF structure of the tank. In the paper we will show the results of the investigation for the origin of the X-ray radiation from the tank.