Please use this identifier to cite or link to this item: https://doi.org/10.1063/1.1145572
DC FieldValue
dc.titleOxides as thermionic sources of Mg+, Ca+, Sr +, and Ba+ ions
dc.contributor.authorTan, T.L.
dc.contributor.authorZhou, Z.L.
dc.contributor.authorOng, P.P.
dc.date.accessioned2014-10-16T09:35:47Z
dc.date.available2014-10-16T09:35:47Z
dc.date.issued1995
dc.identifier.citationTan, T.L., Zhou, Z.L., Ong, P.P. (1995). Oxides as thermionic sources of Mg+, Ca+, Sr +, and Ba+ ions. Review of Scientific Instruments 66 (4) : 2879-2882. ScholarBank@NUS Repository. https://doi.org/10.1063/1.1145572
dc.identifier.issn00346748
dc.identifier.urihttp://scholarbank.nus.edu.sg/handle/10635/97481
dc.description.abstractGroup II metal oxides (MgO, CaO, SrO, and BaO) were coated on tungsten or tantalum filaments to form thermionic emitters of positive metal ions. The choice between tungsten and tantalum for optimum performance was empirically found to depend on the oxide material. Total ion emission current and ion purity were generally found to increase with temperature. A stable source of high purity (up to 97%) Ba+ ions could be obtained from the BaO-coated filament at 1800 °C after 150 min of heating. At 1600 °C, the SrO-coated filament could produce a relatively stable ion current and purity of 97% of Sr+ ions. Very pure (99.8%) Ca+ ions were emitted at 1950 °C. However more stable ion current though less pure ions (87% of Ca + at 1800 °C) were obtained at lower temperatures. MgO-coated filaments using tungsten or tantalum wires were found to be unsuitable as a source of Mg+ ions. All the filaments of MgO, CaO, SrO, and BaO were found to produce larger ion current and higher ion purity at higher temperatures. In general, the relative isotopic abundances of ions produced by a thermionic source are reproduced by the natural isotopic abundances of the corresponding metal. It implies that the slight differences in the nuclear masses of the isotopes do not introduce any significant effect on their ion production efficiency. Between tantalum and tungsten as a choice for the filament material, tantalum was found to be a better choice for Ba+ and Sr+ ions, while tungsten was better for Ca+. © 1995 American Institute of Physics.
dc.description.urihttp://libproxy1.nus.edu.sg/login?url=http://dx.doi.org/10.1063/1.1145572
dc.sourceScopus
dc.typeArticle
dc.contributor.departmentPHYSICS
dc.description.doi10.1063/1.1145572
dc.description.sourcetitleReview of Scientific Instruments
dc.description.volume66
dc.description.issue4
dc.description.page2879-2882
dc.identifier.isiutA1995QT33100023
Appears in Collections:Staff Publications

Show simple item record
Files in This Item:
There are no files associated with this item.

Page view(s)

57
checked on Nov 29, 2020

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.