| 摘要 |
PURPOSE: To use ions efficiently and improve sensitivity even for low concentration ions by outputting a packet of ions by a pseudo random sequence and focusing ions in the packet so as to act on each packet. CONSTITUTION: A time-of-flight mass spectrometer 40 has an ion source 42 and an extraction grid 44. The ion source 42 continuously generates ions 46. The spectrometer 40 has a pulse-time encoder 48, which supplies control signals to the extraction grid 44 and outputs a packet of ions at intervals during which some overlaps are caused when the packet approaches a detector 50. A pseudo random sequence is taken as an encoded sequence to output the packet. Moreover, a plate 52 and a voltage source 54 are provided to compensate the space distribution and the velocity distribution of ions in the packet discharged from the ion source 42 by focusing ions. As a result, sensitivity of the spectrometer 40 can be increased by effective usage of ions. |
