A Time-of-flight type near backscattering spectrometer DNA in J-PARC

Shibata, Kaoru  

A time-of-flight (TOF) type near-backscattering spectrometer (n-BSS), DNA was built and started operation in 2012 at the Materials and Life Science Experimental Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). DNA is a unique instrument among spallation pulsed neutron facilities over the world in terms of n-BSS equipped with a high-speed pulse-shaping disc-chopper. On the other hand Si crystal analyzers with back-coated by neutron absorber extremely reduces unfavorable background scattering of the instrument so as to reach signal-to-noise ratio of ~100,000. Those factors gave big advantage to enlarge application fields to dynamical behaviors of atoms and spins in bio-molecules, soft-materials and strongly-correlated electron system in nanosecond timescale or in micro-eV energy region. I will present the performance of DNA spectrometer and their research results.