Search results for "Triplet lens"
showing 2 items of 2 documents
Characterisation of beam focus quality in biomedical nuclear microscopy: A Fourier optics approach
2009
Abstract The central peak widths of the 2D-autocorrelation function have been investigated as a Figure of Merit (FoM) of focus quality in nuclear microscopy using a quadrupole triplet lens system. The beam focus could be reliably characterised for direct scanning transmission ion microscopy (direct-STIM) images obtained with fluences as small as 5.8 × 10 9 ions cm - 2 which colocalisation tests showed did not introduce significant beam-induced changes in the cells.
A gas ionisation Direct-STIM detector for MeV ion microscopy
2015
Abstract Direct-Scanning Transmission Ion Microscopy (Direct-STIM) is a powerful technique that yields structural information in sub-cellular whole cell imaging. Usually, a Si p-i-n diode is used in Direct-STIM measurements as a detector. In order to overcome the detrimental effects of radiation damage which appears as a broadening in the energy resolution, we have developed a gas ionisation detector for use with a focused ion beam. The design is based on the ETH Frisch grid-less off-axis Geiger–Muller geometry. It is developed for use in a MeV ion microscope with a standard Oxford Microbeams triplet lens and scanning system. The design has a large available solid angle for other detectors …