Development of the bunch shape monitor using the carbon-nano tube wire

Kitamura, Ryo   ; Hayashi, Naoki  ; Hirano, Koichiro  ; Kondo, Yasuhiro   ; Moriya, Katsuhiro  ; Oguri, Hidetomo  ; Futatsukawa, Kenta*; Miyao, Tomoaki*; Otani, Masashi*; Kosaka, Satoshi*; Nemoto, Yasuo*

A bunch shape monitor (BSM) is one of the important instruments to measure the longitudinal phase space distribution. For example in the J-PARC linac, three BSMs using the tungsten wire are installed at the ACS section to measure the bunch shapes between the accelerating cavities. However, this conventional BSM is hard to measure the bunch shape of H beam with 3 MeV at the beam transport between the RFQ and DTL sections, because the wire is broken around the center region of the beam. The new BSM using the carbon-nano-tube (CNT) wire is being developed to be able to measure the bunch shape of the H beam with 3 MeV. The careful attention should be paid to apply the high voltage of 10 kV to the CNT wire. The several measures are taken to suppress the discharge from the wire and operate the CNT-BSM. This presentation reports the current status of the development and future prospective for the CNT-BSM.