Chemical Ionization Mass Spectrometry Using Carbon Nanotube Field Emission Electron Sources

Radauscher, Erich; Keil, Adam D.; Wells, Mitch; Amsden, Jason J.; Piascik, Jeffrey R.; Stoner, Brian R.; Glass, Jeffrey T.

doi:10.1007/s13361-015-1212-0

Cited by 14 publications

(8 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To date, cathode fabrication batch runs have produced satisfactory yields of field emitters that have performed well in whole-chip field emission testing, both in levels of current emitted (from 10 to several hundred μA over 100 emitters) and in cathode performance over hundreds of hours of emission (lifetesting; Fig. 8) similar to previous reports for CNT emitters in other applications (e.g., [25]).…”

Section: Emitter Testingsupporting

confidence: 72%

Future planetary instrument capabilities made possible by micro- and nanotechnology

Getty

Lim

Grubisic

et al. 2019

Micro- And Nanotechnology Sensors, Systems, and Applications XI

View full text Add to dashboard Cite

A number of new instrument capabilities are currently in maturation for future in situ use on planetary science missions. Moving beyond the impressive in situ instrumentation already operating in planetary environments beyond Earth will enable the next step in scientific discovery. The approach for developing beyond current instrumentation requires a careful assessment of science-driven capability advancement. To this end, two examples of instrument technology development efforts that are leading to new and important analytical capabilities for in situ planetary science will be discussed: (1) an instrument prototype enabling the interface between liquid separation techniques and laser desorption/ionization mass spectrometry and (2) an addressable excitation source enabling miniaturized electron probe microanalysis for elemental mapping of light and heavy elements.

show abstract

Section: Emitter Testingsupporting

confidence: 72%

Future planetary instrument capabilities made possible by micro- and nanotechnology

Getty

Lim

Grubisic

et al. 2019

Micro- And Nanotechnology Sensors, Systems, and Applications XI

View full text Add to dashboard Cite

show abstract

“…Carbon nanotube (CNT) cold cathode field emitters have been shown to be excellent candidates for integration with MEMS [8][9][10] owing to their outstanding electrical and mechanical properties, allowing for the design and fabrication of complex and innovative integrated VMDs. To date, however, the factors involved with integrating CNTs as field emitters, specifically in situ growth of CNTs on polysilicon substrates, have not been well studied.…”

Section: Introductionmentioning

confidence: 99%

Integrating carbon nanotube forests into polysilicon MEMS: Growth kinetics, mechanisms, and adhesion

Ubnoske

Radauscher

Meshot

et al. 2017

Carbon

Self Cite

View full text Add to dashboard Cite

The growth of carbon nanotubes (CNTs) on polycrystalline silicon substrates was studied to improve the design of CNT field emission sources for microelectromechanical systems (MEMS) applications and vacuum microelectronic devices (VMDs). Microwave plasmaenhanced chemical vapor deposition (PECVD) was used for CNT growth, resulting in CNTs that incorporate the catalyst particle at their base. The kinetics of CNT growth on polysilicon were compared to growth on Si (100) using the model of Deal and Grove, finding activation energies of 1.61 and 1.54 eV for the nucleation phase of growth and 1.90 and 3.69 eV for the diffusion-limited phase on Si (100) and polysilicon, respectively. Diffusivity values for growth on polysilicon were notably lower than the corresponding values on Si (100) and the growth process became diffusion-limited earlier. Evidence favors a surface diffusion growth mechanism involving diffusion of carbon precursor species along the length of the CNT forest to the catalyst at the base. Explanations for the differences in activation energies and diffusivities were elucidated by SEM analysis of the catalyst nanoparticle arrays and through wide-angle X-ray scattering (WAXS) of CNT forests. Finally, methods are presented to improve adhesion of CNT films during operation as field emitters, resulting in a 2.5x improvement.

show abstract

“…The main fragments found for [PETN + Cl] – (Figure c) are NO 3 – and [M – H] − (315 m / z ). Both are common fragmentation products of PETN in vacuo. , …”

Section: Resultsmentioning

confidence: 98%

“…The dwell time at each V DMA2 was 250 ms, during which the DAQ read the electrometer output voltage at a frequency of 50 kHz, averaging it to produce a single value for every V DMA2 . 37,38 RDX is particularly stable and has, to our knowledge, not been previously thermally or electrically fragmented at atmospheric pressure. Exceptionally, RDX fragments provisionally identified as NO 3 − and NO 2 − have been reported in drift tubes heated from 120 to 200 °C, 39 though only in the presence of abundant electrons (produced by a negative discharge in N 2 ).…”

mentioning

confidence: 88%

Ion Mobility Spectrometer-Fragmenter-Ion Mobility Spectrometer Analogue of a Triple Quadrupole for High-Resolution Ion Analysis at Atmospheric Pressure

Amo‐González¹,

Carnicero²,

Perez³

et al. 2018

Anal. Chem.

View full text Add to dashboard Cite

Two differential mobility analyzers (DMAs) acting as narrow band mobility filters are coupled in series, with a thermal fragmentation cell placed in between, such that parent ions selected in DMA are fragmented in the cell at atmospheric pressure, and their product ions are analyzed on DMA. Additional mass spectrometer analysis is performed for ion identification purposes. A key feature of the tandem DMA is the short residence time (∼0.2 ms) of ions in the analyzer, compared to tens of milliseconds in drift tube ion mobility spectrometers (IMS). Ion fragmentation within the analyzer and associated mobility tails are therefore negligible for a DMA but not necessarily so in conventional IMS. This advantage of the DMA is demonstrated here by sharply defined product ion mobility peaks. Ambient pressure ion fragmentation has been previously demonstrated by both purely thermal means as well as rapidly oscillating intense electric fields. Our purely thermal fragmentation cell here achieves temperatures up to 700 °C measured inside the heating coil of a cylindrical ceramic heater, through whose somewhat colder axis we direct a beam of mobility-selected ions. We investigate tandem separation of chloride adducts from the explosives EGDN, nitroglycerine (NG), PETN, and RDX and from deprotonated TNT. Atmospheric pressure fragmentation of the first three ions yields one or several previously reported fragments, providing highly distinctive tandem DMA channels for explosive identification at 1 atm. RDX ions had not been previously fragmented at ambient pressure, yet [RDX + Cl] converts up to 7% (at 300 °C) into a 166 m/ z product. The known high thermal resilience of TNT is confirmed here by its rather modest conversion, even when the ceramic is heated to 700 °C. At this temperature some previously reported fragments are found, but their mobilities are fairly close to each other and to the one of the far more abundant parent ion, making their identification by mobility alone problematic. We anticipate that moderately higher fragmenter temperatures will produce smaller fragments with mobilities readily separated from that of [TNT - H].

show abstract

Chemical Ionization Mass Spectrometry Using Carbon Nanotube Field Emission Electron Sources

Cited by 14 publications

References 42 publications

Future planetary instrument capabilities made possible by micro- and nanotechnology

Future planetary instrument capabilities made possible by micro- and nanotechnology

Integrating carbon nanotube forests into polysilicon MEMS: Growth kinetics, mechanisms, and adhesion

Ion Mobility Spectrometer-Fragmenter-Ion Mobility Spectrometer Analogue of a Triple Quadrupole for High-Resolution Ion Analysis at Atmospheric Pressure

Contact Info

Product

Resources

About