A multi-reflection time-of-flight mass spectrograph for short-lived and super-heavy nuclei

•Demonstrated very fast mass measurements with a multi-reflection time of flight mass spectrograph.•Mass resolving power of Rm≈150,000 was achieved in 1.2-ms for A/q=39 ions.•Mass precision of δmm=7.7×108 was demonstrated for 40Ca+.•Effects of thermal and voltage instabilities are described.•Effects of thermal and voltage instabilities are described. A multi-reflection time-of-flight (MRTOF) mass spectrograph has been implemented at RIKEN to provide high-precision mass measurements of very short-lived nuclei. Of particular interest are mass measurements of r-process nuclei and trans-uranium nuclei. In such nuclei, the MRTOF can perform on par with or better than traditional Penning trap systems. We demonstrate that the MRTOF-MS is capable of accurately attaining relative mass precision of δm/m