Applications of DCEMS or ICEMS for UHV studies of surfaces and interfaces are often severely limited by long recording times. To clarify the practical means to shorten this time, we introduce the "statistical utility rate" α characterizing the statistical quality of a given measurement. By improving detection efficiency and reducing background contribution simultaneously, we have developed an extremely low-noise scintillation detector (Hamamatsu R1635-02 or R2557 photomultiplier with P-47 thin-layer phosphor). Performance comparison with a channeltron by57Fe-DCEMS measurements on an 90% enriched57Fe foil with 7.2 keV electrons reveals a measuring time gain over an order of magnitude in favour of the scintillation e-detector. Improvements achievable for samples with normal isotope abundance are higher than for enriched ones.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Nuclear and High Energy Physics
- Condensed Matter Physics
- Physical and Theoretical Chemistry