Dane Walker - Academia.edu (original) (raw)

Papers by Dane Walker

Vakuum in Forschung Und Praxis, Apr 1, 2022

SummaryConventional mass spectrometry techniques can be used to monitor vacuum quality and contam... more SummaryConventional mass spectrometry techniques can be used to monitor vacuum quality and contaminant species ahead of the fusion process. However, their use in characterizing species used in fusion reactions is limited by the mass interferences that occur with the isotopes of light gases, deuterium and helium for example appear at mass 4. This article describes the use of Threshold Ionization Mass Spectrometry (TIMS) and Ultra‐high resolution Mass Spectrometry, both are effective in the characterization of typical species found in nuclear fusion. The TIMS technique uses the control of ionization potential to selectively ionize species at the same nominal mass, deuterium, D2 a typical fuel used in nuclear fusion and the fusion by‐product 4He, both appear at m/z 4 for example. The development of ultra‐high resolution mass spectrometry, using the second stability zone, “Zone H”, further improves these capabilities, with the detection of interference species by mass. Ultrahigh resolution allows improvements in sensitivity of a factor of 100 over the TIMS method.

Journal of Vacuum Science & Technology B

Previous investigations of mass spectra obtained in very high vacuum systems have disagreed as to... more Previous investigations of mass spectra obtained in very high vacuum systems have disagreed as to the origin and identity of the mass peak frequently observed at m/z = 19 amu. Recent work with quadrupole mass spectrometry instruments that can also be used for threshold ionization mass spectrometry has shown how the apparent conflict between different sets of published data may be resolved.

The replacement of chromate conversion coatings for zinc coated components has been necessitated ... more The replacement of chromate conversion coatings for zinc coated components has been necessitated by the materials finishing industries due to the inherent toxicity issues with Cr(VI) and the legislative enforcement of WEEE and ELV Directives by the European Union. Current replacements are based on non-chromate , Cr(III) systems, these may be perceived by some to be problematic as they still contain chromium . Molybdate based conversion coatings have long been viewed by many researchers to be a viable non-chromium alternative due to their low toxicity. An extensive literature review of the research carried out in the last 20 years was carried out, highlighting areas of interest for improving the corrosion resistance of the coatings studied. These were, primarily, the synergesis that exists with molybdate and phosphate compounds for corrosion resistance and the incorporation of nanoparticle silica into treatment solution. Also discovered was the importance of the acid used to adjust t...

Encyclopedia of Tribology, 2013

Vakuum in Forschung und Praxis, 2022

Conventional mass spectrometry techniques can be used to monitor vacuum quality and contaminant s... more Conventional mass spectrometry techniques can be used to monitor vacuum quality and contaminant species ahead of the fusion process. However, their use in characterizing species used in fusion reactions is limited by the mass interferences that occur with the isotopes of light gases, deuterium and helium for example appear at mass 4. This article describes the use of Threshold Ionization Mass Spectrometry (TIMS) and Ultra‐high resolution Mass Spectrometry, both are effective in the characterization of typical species found in nuclear fusion. The TIMS technique uses the control of ionization potential to selectively ionize species at the same nominal mass, deuterium, D2 a typical fuel used in nuclear fusion and the fusion by‐product 4He, both appear at m/z 4 for example. The development of ultra‐high resolution mass spectrometry, using the second stability zone, “Zone H”, further improves these capabilities, with the detection of interference species by mass. Ultrahigh resolution allows improvements in sensitivity of a factor of 100 over the TIMS method.

Vakuum in Forschung Und Praxis, Apr 1, 2022

SummaryConventional mass spectrometry techniques can be used to monitor vacuum quality and contam... more SummaryConventional mass spectrometry techniques can be used to monitor vacuum quality and contaminant species ahead of the fusion process. However, their use in characterizing species used in fusion reactions is limited by the mass interferences that occur with the isotopes of light gases, deuterium and helium for example appear at mass 4. This article describes the use of Threshold Ionization Mass Spectrometry (TIMS) and Ultra‐high resolution Mass Spectrometry, both are effective in the characterization of typical species found in nuclear fusion. The TIMS technique uses the control of ionization potential to selectively ionize species at the same nominal mass, deuterium, D2 a typical fuel used in nuclear fusion and the fusion by‐product 4He, both appear at m/z 4 for example. The development of ultra‐high resolution mass spectrometry, using the second stability zone, “Zone H”, further improves these capabilities, with the detection of interference species by mass. Ultrahigh resolution allows improvements in sensitivity of a factor of 100 over the TIMS method.

Journal of Vacuum Science & Technology B

Previous investigations of mass spectra obtained in very high vacuum systems have disagreed as to... more Previous investigations of mass spectra obtained in very high vacuum systems have disagreed as to the origin and identity of the mass peak frequently observed at m/z = 19 amu. Recent work with quadrupole mass spectrometry instruments that can also be used for threshold ionization mass spectrometry has shown how the apparent conflict between different sets of published data may be resolved.

The replacement of chromate conversion coatings for zinc coated components has been necessitated ... more The replacement of chromate conversion coatings for zinc coated components has been necessitated by the materials finishing industries due to the inherent toxicity issues with Cr(VI) and the legislative enforcement of WEEE and ELV Directives by the European Union. Current replacements are based on non-chromate , Cr(III) systems, these may be perceived by some to be problematic as they still contain chromium . Molybdate based conversion coatings have long been viewed by many researchers to be a viable non-chromium alternative due to their low toxicity. An extensive literature review of the research carried out in the last 20 years was carried out, highlighting areas of interest for improving the corrosion resistance of the coatings studied. These were, primarily, the synergesis that exists with molybdate and phosphate compounds for corrosion resistance and the incorporation of nanoparticle silica into treatment solution. Also discovered was the importance of the acid used to adjust t...

Encyclopedia of Tribology, 2013

Vakuum in Forschung und Praxis, 2022

Conventional mass spectrometry techniques can be used to monitor vacuum quality and contaminant s... more Conventional mass spectrometry techniques can be used to monitor vacuum quality and contaminant species ahead of the fusion process. However, their use in characterizing species used in fusion reactions is limited by the mass interferences that occur with the isotopes of light gases, deuterium and helium for example appear at mass 4. This article describes the use of Threshold Ionization Mass Spectrometry (TIMS) and Ultra‐high resolution Mass Spectrometry, both are effective in the characterization of typical species found in nuclear fusion. The TIMS technique uses the control of ionization potential to selectively ionize species at the same nominal mass, deuterium, D2 a typical fuel used in nuclear fusion and the fusion by‐product 4He, both appear at m/z 4 for example. The development of ultra‐high resolution mass spectrometry, using the second stability zone, “Zone H”, further improves these capabilities, with the detection of interference species by mass. Ultrahigh resolution allows improvements in sensitivity of a factor of 100 over the TIMS method.