Unbunched mode

In hardware make sure that there is no voltage on the bunching parameter (perform the imaging measurements in unbunched mode for optimal image quality). Before the start of the experiment select under acquisition setup/advanced settings save as raw file, in order to be able to post-process the raw data after the measurement is completed. 

The ion gun is operated at 22 kV utilizing Au ions and in an unbunched mode (high spatial resolution mode) with sub-micron spatial resolution (rrr Note 7). The mass resolution should be at the same time good enough to distinguish species of similar nominal mass like Ca+ (w/z=39.963) and C3H4+ (w/z=40.031) in order to accurately map their distributions. 

Imaging mode also referred to as Unbunched mode. This is used when a finely focused beam is needed. As this requires the Gaussian mode of focusing, the spot size scales with the primary ion beam current. 

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