International audienceThe objective of this project is the development of the SIMS associated to a new probe of the solid: massive clusters consisting of 100–1000 bismuth or gold atoms. The systematic study of the ionic emission intensities as a function of the mass and energy of these projectiles showed that 100–200 qkeV is sufficient energy for the new probe. It is possible to obtain a time of flight (ToF) spectrum with a single impact. These spectra permit to characterize light molecules (MW∼ a few hundreds) with their fragments and intact molecular ion peaks. To analyze the surface, we propose to obtain cluster beams of 100–150 qkeV with a diameter of 10–100 µm, and to associate measurements of time of flight mass spectrometry with the detection of electron emission in order to locate the impact on the surface. We describe the simulation and the installation, on a 130 kV platform, of our column including a LMIS (Liquid Metal ion Source), lenses and Wien Filter, and of a focusing beam line made of an accelerating gap with its shield and a 130 kV insulator. We shall give the experimental beam specifications obtained with the massive cluster ion source Pegase for bismuth and gold

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The detection of coincidental emissions (electron–ion, ion–ion, photon–ion) can enhance the amount of information available in desorption time‐of‐flight mass spectrometry (TOF‐MS) by identifying physical, chemical and/or spatial correlations. This paper outlines the conditions for coincidence measurements and the methodology for identifying correlations. Applications of coincidence–correlation mass spectrometry include the study of the composition and structure of polyatomic ions, the process involved in ion production from solids and the chemical microhomogeneity of surfaces. © 1997 John Wiley & Sons, Ltd.

We assembled hardware and software for the synchronized detection of electrons and ions emitted under the impacts of the individual C 60 + and C 60 2+ ions. A projectile impact is localized via the ejected electron(s) with an emission electron microscope (EEM). The (x,y) coordinates of each impact combined with the corresponding record of detected secondary ions (Sis), allow the construction of mass-selected surface maps.The setup comprises a custom-built ToF-SIMS with a C 60 1,2+ source, an EEM with an electron imaging detector consisting of dual microchannel plates (MCPs), phosphor screen and a 1.3 megapixel CMOS camera. The electron pulse on the aluminized phosphor screen triggers the camera resulting in a frame with the electron image. It also triggers the ToF electronics resulting in a suite of SI time records corresponding to each individual impact event. The data processing and management are handled by custom software including combination of the positional and the mass spectrometric information from each impact.The present study demonstrates the feasibility of mapping a surface by localizing the SI emission from single C 60 2+ impacts. A spatial resolution of 1.3 µm has been obtained. Interestingly, maps of coemitted SIs from a given localization display chemically resolved information from an emission area of ∼10 2 nm 2 .

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