Multi-Turn Time-of-Flight Mass Spectrometers

Abstract

e mass resolution of a time-of-ight TOF mass spectrometer is directly proportional to its total ight path length. We have developed multi-turn TOF mass spectrometers, where ions are stored in a xed orbit within an electrostatic sector and al-lowed to propagate the said orbit numerous times. With each successive orbit the ight path is correspondingly increasing. e rst multi-turn TOF mass spectrometer, the MULTUM Linear plus, was developed for cometary exploration. e spectrometer consists of four cylindrical electric sectors and 28 electric quadrupole lenses. e size of the analyzer is 40 cm square. Mass res-olution is demonstrated to increase according to the number of ion cycles. A mass resolution of greater than 350,000 was achieved aer 501.5 cycles. Another multi-turn TOF mass spectrometer, the MULTUM II, was also developed in an eort to reduce the number of quadrupole lenses, which consists of only four toroidal electric sectors. We are developing various types of mass spectrometers based on the MULTUM II technology, a TOF/TOF mass spectrometer MULTUM-TOF/TOF, a stigmatic imaging mass spectrometer MULTUM-IMG and miniature mass spectrometers of high mass resolving power MULTUM-S series.