Invited article: Characterization of background sources in space-based time-of-flight mass spectrometers

Area of Science:

• Space plasma physics
• Instrumental analysis
• Mass spectrometry

Background:

• Background signals in time-of-flight (TOF) instruments can compromise space plasma measurements.
• These signals increase data analysis complexity and reduce signal-to-noise ratios, impacting scientific value.

Purpose of the Study:

• To review common background signal sources in TOF mass spectrometers used for space plasma.
• To illustrate the effects of these sources using real data examples.
• To discuss mitigation strategies and design considerations for future instruments.

Main Methods:

• Review of established literature on TOF mass spectrometry background.
• Analysis of data from space plasma instruments ACE-SWICS and MESSENGER-FIPS.
• Identification and categorization of various background signal origins.

Main Results:

• Identified key background sources: penetrating particles, UV photons, energy/angular scattering, electron stimulated desorption, ion-induced electron emission, accidental coincidences, and electronic noise.
• Demonstrated data signatures for each source using instrument examples.
• Provided insights into the impact of each source on data quality.

Conclusions:

• Understanding and mitigating background signals are crucial for accurate space plasma measurements.
• Effective strategies and design considerations can enhance the performance of TOF instruments.
• This review serves as a guide for researchers and instrument designers in the field.