ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
Medium energy (100–300 keV) time-of-flight spectrometry for surface analysis uses the correlated detection of an energetic ion and the secondary electrons emitted as it passes through a carbon foil. When microchannel plates are employed in this detection scheme, a typical mean efficiency of detection of less than 30% is achieved. When instead a surface barrier detector is used to detect the ion, providing simultaneous acquisition of velocity and energy information, certain advantages are realized over the two microchannel plate configuration in the characterization of low level constituents of surfaces. Specifically, energy-discriminated gating of the start pulse was observed to nearly eliminate count rate dependent background in a time-of-flight spectrum. Further reduction in background was obtained by the selective elimination of forward recoil species or backscatters from the substrate. Replacement of the stop microchannel plate by a surface barrier detector has resulted in improved detection efficiency for He, as well as provided a means for further study of the processes which affect time-of-flight spectrometer response, including multiple scattering and secondary electron emission in the start foil. In this publication, we describe the application of this particle telescope to the backscattering analysis of gold on silicon and the forward scattering measurement of hydrogen in a self-supporting carbon film.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1144894
