Brubaker lens

{
  "id": "MLC-T-CHM-001518",
  "term": "Brubaker lens",
  "field": "Chemistry",
  "definition": "A short set of four rod electrodes mounted in line with and just ahead of the main rods of a quadrupole mass filter, driven with part of the radiofrequency voltage but without the DC voltage that the main rods carry. It passes ions above a threshold mass-to-charge ratio, and the delayed onset of the DC component limits defocusing by fringe fields, so more ions are transmitted for the same mass resolution.",
  "synonyms": [
    "Brubaker pre-filter"
  ],
  "subject": "Analytical Chemistry",
  "see_also": [
    "fringe field",
    "transmission efficiency",
    "transmission quadrupole mass spectrometer"
  ],
  "references": [
    "PAC, 2013, 85, 1515. 'Definitions of terms relating to mass spectrometry (IUPAC Recommendations 2013)' on page 1526 (https://doi.org/10.1351/PAC-REC-06-04-06)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/brubaker-lens/"
}