Recent issues of AMATERAS; A Disk-chopper spectrometer at J-PARC

Nakajima, Kenji  ; Kawamura, Seiko   ; Kikuchi, Tatsuya  ; Kawakita, Yukinobu  ; Inamura, Yasuhiro  ; Kajimoto, Ryoichi  ; Nakamura, Mitsutaka   ; Aoyama, Kazuhiro; Kambara, Wataru*; Wakai, Daisuke*

AMATERAS is a cold-neutron disk-chopper spectrometer at Materials and Life Science Experimental Facility (MLF) in J-PARC. As one of the first-generation disk-chopper spectrometers with a pulse shaping chopper, the spectrometer started its operation in 2009. Until May 2016, experiments of more than 80 proposals have been carried out, which have produced 36 papers, 7 theses and nearly a hundred of presentations at scientific meetings. In past 8 years, we have been accumulating experiences of operation of a pulse-shaping-type chopper spectrometer and are facing several problems with a beam-transport, back-ground, chopper operations etc. In this presentation, we will present our experiences and issues with operation of AMATERAS, which might be of help of other similar spectrometers in operation or in the planning stage.