Design and performance of the HVE electrostatic nuclear microprobe

作者：Podaru Nicolae C^*; van de Hoef F L; Gottdang A; Mous D J W

来源：Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms , 2013, 306: 25-28.

DOI：10.1016/j.nimb.2012.11.044

• Electrostatic nuclear microprobe
• Finite element methods
• Ion beam brightness
• DC linear particle accelerator

High Voltage Engineering (HVE) designed, built and tested its first electrostatic nuclear microprobe lens with micrometer lateral resolution, based on the "Russian" quadruplet configuration. Ray tracing and three dimensional finite element methods were applied to quantify the role of spherical and parasitic aberrations, to optimize the lens geometry (e.g. electrode to bore diameter ratio) and to determine allowable mechanical tolerances. The lateral resolution of the nuclear microprobe was measured using a 1.5 MeV He+ ion beam. An image of 6.8 (+/- 0.2) mu m x 6.1 (+/- 0.2) mu m (FWHM) was obtained for an object size of 100 (+/- 1) mu m x 100 (+/- 1) mu m with 0.23 mrad half-angle divergence (33% lens filling). This closely corresponds to the expected beam size based on the calculated theoretical demagnification of 16.08 (15.5 measured). Additionally, this indicates the little contribution of the spherical and parasitical aberrations and a good agreement between design and actual performance.

• 出版日期2013-7-1