Design and Set-up of An External Ion Source Coupled to a Quadrupole-Ion-Trap Reflectron-Time-of-Flight Hybrid Instrument

Abstract

Further results of a new set-up for storing ions generated in an external ion source and trapped in a quadrupole ion trap in combination with a reflectron time-of-flight mass spectrometer (ReTOF) are presented. As a result of this set-up, jet-cooled molecules are introduced as neutrals into the external ion source and ionized by multiphoton absorption processes. A selected mass range of the generated ions can be accelerated into the ion trap to be stored without any buffer gas. The ions are not dispersed for a time duration of several milliseconds in the ion trap, but remain coherent in space and kinetic energy and move in narrow ion clouds describing Lissajous trajectories. The advantage of the external ion source and its influences on the parameters of both the external ion source and the ion trap will be discussed with respect to the signals obtained and compared with SIMION calculations.