The thermal-emission ion source in solid source mass spectrometry

Palmer, George

doi:10.1016/0891-3919(58)90227-4

Cited by 9 publications

(5 citation statements)

References 7 publications

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“…The mass spectrum consisted of the ion-beams 204Pb+, 206Pb+, 2°7Pb+ and 208Pb+. A detailed description and review of the thermal emission ion source in solid-source mass spectrometry has been given by Palmer (1958).…”

Section: Methodsmentioning

confidence: 99%

Lead isotope abundance studies on mineral occurrences in the British Isles and their geological significance

Moorbath

1962

Phil. Trans. R. Soc. Lond. A

100

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Lead isotope abundances are reported for ninety-eight galena specimens from Great Britain and Ireland. The analyses were made with a solid-source mass spectrometer. Comparison analyses show excellent agreement with results from other laboratories using solid-source techniques, but differences of 1 to 5% may occur for individual abundances when comparison is made with laboratories utilizing the lead tetramethyl vapour technique. The model chosen for calculation of ages from the isotopic composition is that of Holmes and Houtermans, using the published values of Patterson for the isotopic comparison of primeval lead in iron meteorites and modern lead in ocean sediments. This model permits calculation of the parameters uranium-238/lead-204 and thorium-232/uranium-238 in the source of the ores, which may exhibit small regional differences. The Holmes-Houtermans model ages of three suites of galenas from south-west England, northern England and southern Norway give excellent agreement with published values of the absolute ages of genetically associated igneous rocks. Other models used for interpreting lead isotope abundances do not generally give such satisfactory agreement. The significance of the isotope data from Great Britain and Ireland is discussed regionally in terms of the age of mineralization as well as the possible correlation and origin of different deposits. Of the ninety-eight leads investigated, eighty-six are assumed to be normal and to obey the conditions of the Holmes-Houtermans model. The remaining twelve are B -type leads, as defined by Houtermans, i.e. the model ages are demonstrably older than the true age of mineralization. The main criteria for recognizing normal leads are, first, the close regional grouping of isotope abundances and, secondly, that the model age does not exceed the age of the enclosing sedimentary rocks on the basis of the most recently published geological time-scales of the fossiliferous strata. Detailed consideration of normal leads suggests the existence of six periods of mineralization in the British Isles, ranging in age from Lower Palaeozoic to Upper Mesozoic. The two most important and clearly defined groups are associated with the Caledonian and Hercynian orogenies, respectively. There is, as yet, no isotopic evidence for Tertiary mineralization in the British Isles. A discussion of the causes of normal lead isotope abundances indicates that the latter could be the result of large-scale crustal homogenization processes in continental geosynclinal-orogenic belts. However, there is not enough critical evidence to identify definitely the source of normal lead ores with either crust or mantle. B -type leads probably arise by comparatively localized remobilization and regeneration of lead from metamorphic basement complexes with high lead/uranium ratios, or low radiogenic lead content. The source of such leads frequently appears to be somewhat heterogeneous and ore solutions may not have the opportunity for extensive mixing before the site of deposition is reached. However, B -type leads in some cases give an approximation to the true age of the basement rocks from which they are derived. Processes of this type probably account for the 5-type leads in the north-west and central highlands of Scotland and in County Galway, western Ireland, where the occurrences are situated in metamorphic basement rocks. No cases have been definitely recognized within the British Isles in which lead has a negative, or anomalously young, model age ( J -type leads). The results presented in this paper do not support the view of Russell and co-workers that most vein-type deposits which have traversed sedimentary rocks exhibit J -type anomalies—a consequence of their suggestion that B -type leads, as defined by Houtermans, should be regarded as normal leads.

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Section: Methodsmentioning

confidence: 99%

Lead isotope abundance studies on mineral occurrences in the British Isles and their geological significance

Moorbath

1962

Phil. Trans. R. Soc. Lond. A

100

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“…As early as 1958, Palmer [14] revealed the formation of BeB and MgB ions. At present, a considerable number of works [53][54][55][56][57][58][59][60][61][62][63] (predominantly performed using high-temperature mass spectrometry) have been devoted to investigation of the vaporization in MO-B 2 O 3 systems (where M is an alkaline-earth ions are equal to 8.4 and 12.0 eV, respectively.…”

Section: Alkaline-earth Metaboratesmentioning

confidence: 98%

“…These authors determined the enthalpies of sublimation of the Na 2 O · B 2 O 3 and Na 2 O · 2B 2 O 3 compounds and established that metaborate congruently vaporizes without decomposition, whereas Na 2 O · 2B 2 O 3 dissociates so that NaBO 2 passes into the vapor and boron oxide is accumulated in the melt. Long before thermodynamic investigations of these compounds began, it was found that Na 2 B ions are formed upon surface ionization of sodium tetraborate [13] and sodium metaborate [14].…”

Section: Alkali Metaboratesmentioning

confidence: 99%

Thermodynamic properties and structure of gaseous metaborates

Лопатин

Stolyarova

2006

Glass Phys Chem

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A review is presented of the data available in the literature on the thermodynamic properties and structure of gaseous metaborates studied by high-temperature mass spectrometry, gas-phase electron diffraction, spectroscopy, and quantum-chemical methods. The reliability and inconsistency of the thermodynamic properties and structural data obtained by these methods for gaseous metaborates are discussed. The specific features of the application of the above methods for investigating the thermodynamic properties and structure of gaseous metaborates at high temperatures are analyzed.

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“…+ in PositiWe Thermal Ionization Mass Spectroscopy. Since M 2 BO 2 + (M represents the alkali element) ions can be emitted from alkali borate without any promoter in PTIMS, Na 2 BO 2 + ion was first employed for the isotopic measurement of boron by Palmer, 38 and then the technique was extensively applied in the field of geochemistry. However, further improvement of precision was limited by isotopic fractionation because of the light mass of the Na 2 BO 2 + ion (m/e ) 89).…”

Section: Emission Of M 2 Bomentioning

confidence: 99%

Effect of Microstructure of Graphite on the Nonreductive Thermal Ion Emission in Thermal Ionization Mass Spectrometry

2010

J. Phys. Chem. A

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The emission behavior of polyatomic ions in the ionization source of thermal ionization mass spectrometry (TIMS) was investigated. The results suggest that the presence of a graphite promoter plays a key role for the formation and stable emission of polyatomic ions, such as M(2)X(+), M(2)BO(2)(+), Cs(2)NO(2)(+), and Cs(2)CNO(+). Our data further implied that the intensity of M(2)X(+) and M(2)BO(2)(+) increases and the emission temperature decreases with increasing cationic and anionic radius. During the boron isotopic measurement using the Cs(2)BO(2)(+)-graphite-PTIMS method, the isobaric interference ion Cs(2)CNO(+) cannot be transformed from nitrate or organic compounds containing an amide group but can be induced by the existence of trace amounts of boron because of its special electron-deficiency property (B(3+)). Characterization on the planar crystalline structure of various graphite samples with SEM, TEM, and Raman spectroscopy confirmed the relationship of the emission capacity of polyatomic ions and the crystal microstructure of graphite and provides direct evidence that graphite with a perfect parallel and equidistant layer orientation shows a beneficial effect on the emission of polyatomic ions in TIMS. The mechanism study on the formation of polyatomic ions opens the possibility to establish high precision methods for isotopic composition analysis of more nonmetal elements with the TIMS technique.

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The thermal-emission ion source in solid source mass spectrometry

Cited by 9 publications

References 7 publications

Lead isotope abundance studies on mineral occurrences in the British Isles and their geological significance

Lead isotope abundance studies on mineral occurrences in the British Isles and their geological significance

Thermodynamic properties and structure of gaseous metaborates

Effect of Microstructure of Graphite on the Nonreductive Thermal Ion Emission in Thermal Ionization Mass Spectrometry

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