Offline commissioning and performance of a multi-reflection time-of-flight mass analyzer with a new configuration

To precisely measure atomic masses and select isotopes of interest, a multi-reflection time-of-flight mass spectrometer is being built at SHANS (Spectrometer for Heavy Atom and Nuclear Structure). Its mass analyzer with a new configuration different from the existed ones has been commissioned successfully with a chopped Cs-133(1+) beam by using a Bradbury-Nielsen gate. The potentials on all electrodes have been optimized by using two-dimensional potential scan method. With the optimized parameter set, an efficiency of 50% has been obtained. The mass resolving power with a time-of-flight of 12.9 ms has been measured to be 74,000, and it has reached 90,000 with a longer time-of-flight of similar to 20 ms.