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Aperture Cleaning

Electron Microscope Aperture Overview

Electron Microscope Aperture, Type A
High quality apertures, specially designed for use in scanning and transmission electron microscopes (SEM, FESEM and TEM), Microprobe systems, Focused Ion Beam (FIB) and X-ray systems. Made with high precision drilled holes and with optimized shape to avoid scattering. The apertures are made to tight tolerances conforming original equipment manufacturers designs, pre-cleaned and individually packed. The apertures are either used as spray apertures in electron beam columns, limiting apertures or final apertures for objective lenses equipped with an aperture changer. Available in Pt/Ir (95:5%), Mo and Au (for some apertures). The Pt/Ir apertures can be cleaned using aperture flaming or heating devices. Molybdenum apertures stored at atmospheric conditions will oxidize rapidly, we can only guarantee Mo apertures for 4-6 weeks after delivery. The smallest hole for Pt/Ir apertures is 5µm, for Mo apertures it is 10µm. Apertures are available for all current brands of EM system manufacturers: FEI/Philips, JEOL, Hitachi, ZEISS/LEO, Cameca, Topcon, Tescan. We also carry aperture sizes used for brands which are no longer manufactured but still in use: ISI/ABT, CamScan, Cambridge Instruments/Leica, Siemens, BalScan, ETEC/Autoscan, SEMCO/ZEISS Novascan and Nanolab. Please see design and specifications below the selection table.

2mm O.D. x 0.1mm (thin) ZEISS, LEO
2mm O.D. x 0.6mm thickness Cambridge/Leica, JEOL, ZEISS (EVO®), LEO, Cameca, Tescan, Siemens
3mm O.D. x 0.1mm (thin) ZEISS, LEO
3.04mm O.D. x 0.25mm thickness AEI, AMRAY, Cambridge S600, JEOL, FEI/Philips (ex PSEM 500), ZEISS, Electroscan, Tescan
4mm O.D. x 0.2mm thickness ISI, ABT, Topcon, Camscan, Balscan
Gold Foil Apertures, 3mm O.D. x 0.25mm thickness ZEISS, LEO, FEI/Philips
Electron Microscope Top Hat Aperture
Top Hat Apertures
ZEISS, LEO
Tantalum Aperture
Tantalum Apertures
FEI/Philips, Amray
Electron Microscope Strip, Multi-hole Aperture
Strip Apertures
Hitachi, JEOL, ISI

The design of the apertures depends on the size of the aperture holes and the thickness of the material.


Tolerances of Round Apertures
Dimension Range Tolerance
Disc size all +0/-0.02mm
Disc thickness all +0/-0.02mm
Aperture holes 5-10µm ±1µm
11-70µm ±2µm
71-300µm ±5µm
301-1000µm ±10µm
Roundness (hole) 5-10µm = 0.1µm
11-200µm = 1.0µm
200µm and up = 2.0µm
Centricity (hole) Up to 7mm Ø 0.02mm

Capillary length of aperture:
1/2 d for 10 - 200µm holes
< 100µm for holes over 200µm
Electron Microscope Apertures, Type A, B, C, D