OFT12 Orthogonal Extraction Time-of-Flight Mass Spectrometer

OFT12 Orthogonal Extraction Time-of-Flight Mass Spectrometer


Orthogonal extraction reflectron time-of-flight spectrometer OFT12, overall length ca. 900 mm, angle between in- and outgoing ion beam ca. 8°, field free drift length ca. 900 mm, two-stage ion reflector for second order energy focusing. The ions are created outside the ion extraction module by continuous ionization and are subsequently transferred with a transfer module into the ion extraction zone of the time-of-flight spectrometer. The ion transfer column incorporates Einzel lenses + apertures for collimation and a gating electrode for filtering of the incoming ions. The ion extraction module employs two-stage ion extraction according to the Wiley-McLaren criterion and uses Behlke switches in push-pull configuration, maximal repetition frequency 40 kHz. Mass resolution M/ΔM = 5000 at mass 130 amu. The spectrometer comes with parallel-wire ion gate to remove unwanted ionic species from the extracted ion beam, located in the Wiley-McLaren time focus of the two-stage ion source.

Reflectron connection flange 8” OD CF (CF150) flange, reflectron drift tube with 200 mm diameter, reflectron pump flange 6” OD CF (CF100) flange, 2.75” OD CF (CF35) flange for the pressure gauge of the reflectron. The instrument is fully uhv compatible and can be baked to 150 °C. The reflectron can be mounted vertically and horizontally.


  • mass analysis of negative ions
  • heavy ion option: three-stage mcp detector combined with 20 kV postacceleration
  • data acquisition based on multiscaler from FastComtec with 250 ps time resolution controlled by software package TOF5.5

OFT12 Orthogonal Extraction Time-of-Flight Mass Spectrometer

OFT12 ion extraction module. The ions are extracted to the right into the time-of-flight spectrometer. The ion transfer module with electron impact ionizer (option) is located on top. Behind the ion extraction region opposite to the ion transfer module there is a mcp detector enabling easy adjustment of direct ion beam (option).