Ion-optical studies for improved ion transmission in multistage isotope-ratio mass spectrometers

Technical Report · Tue Oct 01 04:00:00 EDT 1991

DOI:https://doi.org/10.2172/5043749· OSTI ID:5043749

Stoffels, J J ^[1]; Laue, H J ^[2]

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1. Pacific Northwest Lab., Richland, WA (United States)
2. Purdue Univ., Lafayette, IN (United States)

Theoretical and experimental ion-optical studies of multistage isotope-ratio mass spectrometers were conducted to determine what improvement in ion transmission efficiency might be attainable through design changes. The computer program GIOS (General Ion Optical Systems) was used to perform theoretical calculations of focusing properties and ion transmission efficiency. Actual transmission through multiple-sector instruments was determined from measurements of the ion beam vertical profile at the focus of each stage. For existing mass spectrometers with tandem magnets of normal geometry, our studies determined a feasible design change that significantly increases ion transmission through the analyzer. The use of a cylindrical einzel lens or an electrostatic quadrupole lens near the focal point between the magnets provides vertical focusing of the ion beam to achieve the improved transmission. We also established a new mass spectrometer design that give 100% transmission through tandem magnetic analyzers and through a third-stage electrostatic analyzer without the use of an intermediate focusing lens. Non-normal magnetic field boundaries provide ion beam focusing in the vertical plant to achieve this complete transmission. 19 refs., 27 figs., 3 tabs.

• Research Organization: Pacific Northwest Lab., Richland, WA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 5043749
• Report Number(s): PNL-7829; ON: DE92002836
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
426000 -- Engineering-- Components
Electron Devices & Circuits-- (1990-)
440800* -- Miscellaneous Instrumentation-- (1990-)
47 OTHER INSTRUMENTATION
BEAMS
DESIGN
ELECTROSTATIC LENSES
FEASIBILITY STUDIES
FOCUSING
ION BEAMS
ISOTOPE RATIO
LENSES
MASS SPECTROMETERS
MEASURING INSTRUMENTS
MODIFICATIONS
SPECTROMETERS