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

Apr 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: Solving molybdenum disulfide's 'thin' problem

add to favorites email to friend print save as pdf

Related Stories

Unexplained warm layer discovered in Venus' atmosphere

Mar 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 ...

Getting a critical edge on plutonium identification

Mar 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 ...

Intergalactic GPS will guide you through the stars

Mar 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) ...

Don't sound the death knell for the PC just yet

Jan 07, 2015

A year ago, pundits were declaring the personal computer dead. Smartphones and tablets were cannibalizing sales, and the once-revolutionary PC seemed unnecessary—and boring.

Mystery of dwarf galaxy could be ejected black hole

Nov 19, 2014

An international team of researchers analyzing decades of observations from many facilities—including the W. M. Keck Observatory on Mauna Kea, the Pan-STARRS1 telescope on Haleakala and NASA's Swift satellite—has ...

Recommended for you

Solving molybdenum disulfide's 'thin' problem

Mar 27, 2015

The promising new material molybdenum disulfide (MoS2) has an inherent issue that's steeped in irony. The material's greatest asset—its monolayer thickness—is also its biggest challenge.

Designer's toolkit for dynamic DNA nanomachines

Mar 26, 2015

The latest DNA nanodevices created at the Technische Universitaet Muenchen (TUM)—including a robot with movable arms, a book that opens and closes, a switchable gear, and an actuator—may be intriguing ...

User comments : 0

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.