engleski

Design and performance of single ion hit detection system at RBI ion microprobe

There is a wide range of materials which are suitable for the nanostructuring using medium energy (≤1MeV/u) heavy ion beams. Only a few existing ion microprobes, including the one at the Ruđer Bošković Institute can focus medium energy heavy ion beams with a spatial resolution below 1 micrometer. Since the use of single ion positioning possibility can offer additional perspectives of patterning materials using ion tracks, we have tested several ion hit detection procedures. Heavy ions have been produced in 6 MV Tandem Van de Graaff accelerator of the Ruđer Bošković Institute. Low demagnification focusing was performed using a doublet from the first two quadropoles of the Oxford triplet configuration. Higher demagnification focusing system using a quintuplet configuration is now in testing stage. Both systems can focus low currents (fA) of heavy ion beams to submicron spotsizes with maximum ion ME/q2 of 25. In the view of these capabilities, we have constructed an ion hit detection system based on secondary electron and/or photon emission. Compared to systems based on detection of transmitted ions (STIM), systems that use light or electrons do not require thin samples that are transparent to the ion beam because secondaries are detected from the surface exposed to the beam. In this work, design and performance measurements of developed single ion hit detection system are presented.

swift heavy ion; ion track; ion microprobe

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