In general, objective pole pieces with small top bore in TEMs have been suggested to have advantages of low spherical and chromatic aberrations and reduced condenser action. TEMs with side-entry specimen stages, shielded objective pole pieces have to be used.

Some manufacturers of transmission electron microscopes (TEMs) use removable pole-pieces and in these instruments, the pole-piece can be exchanged for a custom design. turboTEM have expertise in the design, manufacture and installation of bespoke TEM pole-pieces.

A pole piece is a structure composed of material of high magnetic permeability that serves to direct the magnetic field produced by a magnet. A pole piece attaches to and in a sense extends a pole of the magnet, hence the name. Pole pieces are used with both permanent magnets and electromagnets.

While a smaller pole-piece gap will result in reduced spherical and chromatic aberrations, and therefore improved resolution, a larger gap offers wider flexibility for sample-tilting, tomography, in-situ experiments, or energy-dispersive x-ray spectroscopy (EDX) collection efficiency.

Instead, we propose a User Adjustable Pole-piece (UAP) where the pole-piece gap can be adjusted by the TEM operator without the need for engineer support or losing the column vacuum. This project was initiated in April 2018 to explore the feasibility of constructing an adjustable lens.

Oct 23, 2012 · "Polepiece" is a magnetic pole made of a soft magnetic material (pure iron, permendur), which concentrates the magnetic flux produced by the electromagnet and guided by the yoke to produce a strong magnetic field in a narrow gap (space) in the polepiece.

The electron path is further constricted by a brass lining inside this space known as the pole piece. The pole piece has a small gap within it at which point the beam is most influenced by the electromagnetic current. This is appropriately referred to as the pole piece gap.

Sep 1, 2020 · Simplified drawing of the proposed User Adjustable Pole-piece (UAP) showing a) a small ultra-high-resolution gap, b) an intermediate gap, and c) an expanded experimental gap for analytical or...

In summary, this article is prepared as a guide for scientists and engineers interested in learning about, and/or using advanced S/TEM techniques to characterize interfaces in polycrystalline...

Examples of pole piece gaps in the objective lenses in EMs are HD 2700C SEM/STEM has a 3.8 mm gap and HD 2300A SEM/STEM has 5 mm gap. Figure 2943 shows the schematic illustration of top-entry specimen stage together with the top-entry lens in TEMs.