The Influence of Time-of-Flight (TOF) Mass Spectra Peak Resolution on Elemental Detection Limits for Atom Probe Instrumentation

AbstractThe benefits of using kinetic-energy information to aid ion discrimination in atom probe tomography (APT) are explored. Ion peak interferences in time-of-flight (TOF) mass spectra are categorized by difficulty of discrimination using TOF and kinetic-energy information. Several of these categories, which are intractable interferences when only TOF information is available, may be discriminated when kinetic-energy information also is available. Furthermore, many opportunities for removing noise from composition determinations and three-dimensional images are enabled. Modest kinetic-energy resolving powers (KRPs) of 10 or so should be sufficient to have a major impact on APT. With KRP of about 100, the energy deficits in voltage pulsing may be resolved to enable peak discrimination in straight-flight-path instruments. Real examples and simulated mass spectra are used to illustrate the benefits of kinetic-energy discrimination. Many of the conclusions are applicable generally in TOF spectroscopy. Current detectors do not provide the kinetic energy of incoming ions, but there are realistic prospects for building such detectors and these are discussed. A program to develop these detectors should be pursued.

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Investigation of Atmospheric Pressure Photochemical Ionization Mass Spectra of Binary Organic Solutions without Their Separation in Dependence on the Concentration of Solutions and Analyte Vapors in Nitrogen Using the Exponential Dilution Method and a Time-of-Flight Mass Spectrometer with an Atmospheric Pressure Photochemical Ionization Ion Source

Journal of Analytical Chemistry ◽

10.1134/s1061934820140117 ◽

2020 ◽

Vol 75 (14) ◽

pp. 1743-1748

Author(s):

I. A. Revelsky ◽

A. A. Sysoev ◽

A. I. Revelsky ◽

A. G. Adamov ◽

S. S. Poteshin ◽

...

Keyword(s):

Mass Spectrometer ◽

Atmospheric Pressure ◽

Mass Spectra ◽

Time Of Flight ◽

Ion Source ◽

Dilution Method ◽

Ionization Mass ◽

Concentration Of Solutions ◽

Exponential Dilution ◽

Organic Solutions

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On the Field Evaporation Behavior of a Model Ni-Al-Cr Superalloy Studied by Picosecond Pulsed-Laser Atom-Probe Tomography

Microscopy and Microanalysis ◽

10.1017/s1431927608080963 ◽

2008 ◽

Vol 14 (6) ◽

pp. 571-580 ◽

Cited By ~ 23

Author(s):

Yang Zhou ◽

Christopher Booth-Morrison ◽

David N. Seidman

Keyword(s):

Atom Probe Tomography ◽

Mass Spectra ◽

Pulsed Laser ◽

Picosecond Laser ◽

Atom Probe ◽

Resolving Power ◽

Noise Levels ◽

Thermally Activated ◽

Mass Resolving Power

AbstractThe effects of varying the pulse energy of a picosecond laser used in the pulsed-laser atom-probe (PLAP) tomography of an as-quenched Ni-6.5 Al-9.5 Cr at.% alloy are assessed based on the quality of the mass spectra and the compositional accuracy of the technique. Compared to pulsed-voltage atom-probe tomography, PLAP tomography improves mass resolving power, decreases noise levels, and improves compositional accuracy. Experimental evidence suggests that Ni2+, Al2+, and Cr2+ ions are formed primarily by a thermally activated evaporation process, and not by post-ionization of the ions in the 1+ charge state. An analysis of the detected noise levels reveals that for properly chosen instrument parameters, there is no significant steady-state heating of the Ni-6.5 Al-9.5 Cr at.% tips during PLAP tomography.

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A Method for Calculating m/e's of Peaks from Time-of-Flight Mass Spectra

Applied Spectroscopy ◽

10.1366/000370272774352128 ◽

1972 ◽

Vol 26 (3) ◽

pp. 403-404

Author(s):

F. G. Doolittle ◽

D. G. Earnshaw

Keyword(s):

Mass Spectra ◽

Time Of Flight

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Capillary ionic liquid electrospray: beam compositional analysis by orthogonal time-of-flight mass spectrometry

Journal of Fluid Mechanics ◽

10.1017/jfm.2021.783 ◽

2021 ◽

Vol 928 ◽

Author(s):

S.W. Miller ◽

J.R. Ulibarri-Sanchez ◽

B.D. Prince ◽

R.J. Bemish

Keyword(s):

Mass Spectrometry ◽

Mass Spectra ◽

Time Of Flight ◽

Ion Source ◽

High Mass ◽

Atomic Mass Unit ◽

Flow Rates ◽

Charged Species ◽

Flight Mass Spectrometry ◽

Jet Breakup

Orthogonal time-of-flight mass spectrometry has been used to characterize the kinetic energy and charged species distributions from an in vacuo electrospray ion source for four different ionic liquids at volumetric flow rates between 0.3 and 3.3 nanolitres per second. In all cases, the mass spectra revealed charged species consisting of singly charged and multiply charged ions as well as two broad, unresolved droplet distributions occurring in the 104 to 106 atomic mass unit per charge range. The mean jet velocity and mean jet breakup potential were established from analysis of the energy profile of the high mass-to-charge droplets. At the jet breakup point, we find the energy loss and the jet diameter flow rate dependence of the electrospray beam to be similar to that determined by Gamero-Castaño (Phys. Fluids, vol. 20, 2008, 032103; Phys. Rev. Fluids, vol. 8, 2021, 013701) for 1-ethyl-3-methylimidazolium bis(trifluromethylsulfonyl)imide at similar volumetric flow rates. Similar trends are observed for all four liquids over the flow regime. A jet instability analysis revealed that jet electrification and viscous effects drive the jet breakup from the case of an uncharged, inviscid jet; jet breakup occurs at droplet and jet radius ratios that deviate from 1.89. Using the analytically determined ratio and the beam profile, different species are modelled to reconstruct the mass spectra; primary droplets constitute only a fraction of the total species present. The populations of the species are discussed.

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