An optimized three-dimensional linear-electric-field time-of-flight analyzer

Journal Article · Sat May 15 00:00:00 EDT 2010 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3429941· OSTI ID:22053698

Gilbert, J A; Lundgren, R A; Panning, M H; Rogacki, S; Zurbuchen, T H ^[1]

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1. University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109-2143 (United States)

In situ measurements of the dynamics and composition of space plasmas have greatly improved our understanding of the space environment. In particular, mass spectrometers that use a combination of electrostatic analyzers and time-of-flight systems can identify revealing dynamic and compositional characteristics of ions, and thus constrain their sources and the physical processes relevant for their transport. We demonstrate an optimized design of a linear-electric-field time-of-flight technology that can be used to obtain a high signal to noise: ions that follow an energy-isochronous oscillation within the instrument impact an emissive plate and cause secondary electrons to be sent toward the detector, triggering a high-resolution measurement. By focusing these secondary electrons to a central area on a position-sensitive anode, their signals are separated from ions and neutrals that do not experience energy-isochronous motion. Using their impact positions, the high mass resolution measurements are easily distinguished from other signals on the detector, leading to very favorable signal-to-noise ratios. This optimization provides an improvement to existing technologies without increasing the instrument size or complexity, and uses a novel time-of-flight circuit that combines timing and position information from many signals and ions.

• OSTI ID: 22053698
• Journal Information: Review of Scientific Instruments, Vol. 81, Issue 5; Other Information: (c) 2010 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
ANODES
CHARGED-PARTICLE TRANSPORT
DESIGN
ELECTRIC FIELDS
ELECTRON EMISSION
ELECTRONS
ELECTROSTATIC ANALYZERS
FOCUSING
IONS
MASS RESOLUTION
OPTIMIZATION
OSCILLATIONS
PLASMA
SIGNAL-TO-NOISE RATIO
THREE-DIMENSIONAL CALCULATIONS
TIME-OF-FLIGHT METHOD