| 摘要 |
PCT No. PCT/EP95/01767 Sec. 371 Date Feb. 9, 1996 Sec. 102(e) Date Feb. 9, 1996 PCT Filed May 10, 1995 PCT Pub. No. WO95/31000 PCT Pub. Date Nov. 16, 1995The invention pertains to a process for operating a time-of-flight secondary ion mass spectrometer for analysis of mass spectra, wherein a number of finely structured mass ranges appear in isolation at major intervals, involving the following steps: a) a surface of a material sample is bombarded with primary ion pulses that follow each other at regular time intervals tz (cycle time), b) the secondary ions of various masses m released from the material sample surface by the primary ions are accelerated to the same energy, c) the mass-dependent time of flight t is measured over a path 1 and the mass is determined therefrom. To increase the resolution and the signal-to-noise ratio the process is characterized in that: d) each primary ion pulse consists of a number of subpulses, e) each subpulse is so narrow that it allows for resolution of the finely structured mass ranges, g) the number n of subpulses is selected so that nxtB is smaller than the intervals between the finely structured mass ranges, h) the n subpulse spectra of each finely structured mass range are added up.
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