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

作者：Gilbert J A^*; Lundgren R A; Panning M H; Rogacki S; Zurbuchen T H

来源：Review of Scientific Instruments, 2010, 81(5): 053302.

DOI：10.1063/1.3429941

• astrophysical plasma
• plasma diagnostics
• plasma oscillations
• secondary electron emission
• time of flight mass spectrometers

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.

• 出版日期2010-5