Novel Ion Optics Design Ensures High Sensitivity And Mass Resolution For 3D Atom Probe

April 15, 2005

The combination of the high mass-resolution reflectron lens and a patented, three pair delay line detector brings exceptional sensitivity to the 3-Dimensional Atom Probe (3DAP) from Oxford nanoScience Ltd. This unique combination brings the best atom probe mass resolution available commercially both at the conventionally quoted Full Width at Tenth Maximum (FWTM) and the much more challenging Full Width Thousandth Maximum (FW0.1%M). This makes the instrument particularly well suited to the detection of small quantities of dopant materials. In addition, unlike other commercially available detectors, up to 98.5% of the detected atoms are both spatially located and chemically identified.

The large-acceptance-angle reflectron lens is an ion mirror which uses an electrostatic field to reflect ions towards detector. This configuration gives outstanding mass resolution and brings new standards to signal measurement for 3-Dimensional Atom Probe instruments.

Mass resolution figures (M/DM) of 350 can be achieved at the conventionally quoted FWTM. Good resolution figures at the much more demanding FW0.1%M are a much better indicator of extremely narrow peaks without trailing edges. The use of the reflectron lens allows resolution figures of around 100 to be quoted at FW0.1%M. Specifying resolution figures much closer to the spectral baseline indicates the ability to identify small peaks adjacent to major peaks that are several orders of magnitude higher.

The extremely narrow peaks produced and high signal-to-noise ratio allow accurate chemical analysis of complex alloys, where elemental peaks may be closely spaced in the mass spectrum and where some elements may only be present at low percentage levels.

Chemical identification and spatial location of a high proportion of detected atoms is of critical importance in determining the precision of measurements of low dopant concentrations where the detection of high levels of atoms are essential to guarantee low standard deviations on the measurements. In addition, overall sensitivity is a function of both the mass resolution and number of atoms counted.

The patented delay line detector features three pairs of low resistance wires wound around a hexagonal support. The three sets of delay lines allow discrimination of multiple ions arriving at the same time at the detector.

Explore further: Reshaping mountains in the human mind to save species facing climate change

Related Stories

Dusty substructure in a galaxy far far away

April 1, 2015

Scientists at the Max Planck Institute for Astrophysics (MPA) have combined high-resolution images from the ALMA telescopes with a new scheme for undoing the distorting effects of a powerful gravitational lens in order to ...

Unexplained warm layer discovered in Venus' atmosphere

March 25, 2015

A group of Russian, European and American scientists have found a warm layer in Venus' atmosphere, the nature of which is still unknown. The researchers made the discovery when compiling a temperature map of the upper atmosphere ...

Getting a critical edge on plutonium identification

March 24, 2015

A collaboration between NIST scientists and colleagues at Los Alamos National Laboratory (LANL) has resulted in a new kind of sensor that can be used to investigate the telltale isotopic composition of plutonium samples – ...

Intergalactic GPS will guide you through the stars

March 10, 2015

Lost in the Universe? Need some precise navigation through the bulk of stars in the night sky? Don't worry, there will be an instrument for that - the Multi-Object Optical and Near-infrared Spectrograph (MOONS) at the European ...

Recommended for you

Magnetism at nanoscale

August 3, 2015

As the demand grows for ever smaller, smarter electronics, so does the demand for understanding materials' behavior at ever smaller scales. Physicists at the U.S. Department of Energy's Ames Laboratory are building a unique ...

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Study calculates the speed of ice formation

August 3, 2015

Researchers at Princeton University have for the first time directly calculated the rate at which water crystallizes into ice in a realistic computer model of water molecules. The simulations, which were carried out on supercomputers, ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.