Recent Progress on DNA ToF Backscattering Spectrometer in MLF, J-PARC

Abstract

DNA is a time-of-flight backscattering neutron spectrometer installed at the Materials and Life Science Experimental Facility in J-PARC. After opening user program, we have been developing and upgrading DNA. The energy resolution is improved and achieved the designed value of 1.4 μeV by renewing the disks of the pulse shaping chopper that can rotate at max 300 Hz instead of 225 Hz of the previous disks. The installation of Si311 analyser mirrors has been almost accomplished, which extends momentum transfer region up to 3.7 Å -1 . We demonstrate the effect of this extension by measuring and analysing methyl rotation dynamics in solid toluene at 10 K and 40 K. We also report variety of sample environment available at DNA and their remote handling.