Internal microbeam line

Responsible scientist: Mª Dolores Ynsa Alcalá

This line is an extension of the Standard beam line that allows the focussing of a wide range of ion beams, from protons (up to 10 MeV) to heavy ions such as B, O, or Si (with tens of MeV).

The line was originally designed at the Micro-Analytical Research Centre (Melbourne). The beam collimation is carried out with two precise sets of micrometric X-Y slits: motorized object slits (built by TB Fischer) and manual collimator slits (manufactured at Croatia). A set of five quadrupole lenses, which optically resembles the CSIRO-GEMOC system, is used to focus the beam. The configuration of these lenses is conditioned by the magnetic rigidity of the beam. A 2 MeV proton beam can be focused routinely with spatial resolutions of 2 μm × 2 μm and currents higher than 1 nA, while heavy ions can easily reach a spot size of about 5 μm × 5 μm with about 500 pA current. The focused beam is scanned over the sample with a magnetic deflector. Two positional stages can be used to hold the samples: a manual XYZ manipulator (McAllisterMA1006) covers 150mm vertically and 25mm in X and Z directions, and a piezoelectric XYZ positioning stage (MechOnicsMS30), which travels 60 mm in one direction and 30 mm in other two directions, with a positioning accuracy better than 100 nm. An optical microscope is used to control the beam-sample alignment. The analysis chamber is equipped with a surface barrier Si detector for RBS, a X-ray detector for PIXE and a photodiode (placed behind the sample) for STIM analysis.