The scattering of hydrogen from a cesiated tungsten surface

Wunnik, John N.M. Van; Geerlings, J.J.C.; Granneman, E. H. A.; Los, J.

doi:10.1016/0039-6028(83)90117-6

Cited by 111 publications

(37 citation statements)

References 10 publications

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“…6 An extensively studied combination is Cs/W͑110͒, used either with 0.6 monolayer or a full monolayer of Cs. [7][8][9] The WF shows a minimum of 1.45 eV for the submonolayer coverage and equals the value of bulk Cs ͑2.15 eV͒ for the full monolayer, which is far below the WF of bare W͑110͒ substrate of 5.25 eV. The same mechanism works for barium which has a bulk WF of 2.5 eV.…”

Section: Introductionmentioning

confidence: 77%

Metallic work function measurement in the range 2–3.3 eV using a blue light-emitting diode source

Schletti

Würz

Fröhlich

2000

Review of Scientific Instruments

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A new photoelectric method to monitor the work function of contaminated metallic surfaces in the range 2–3.3 eV using blue light-emitting diodes (LEDs) is presented. This method was specifically developed for an application onboard a spacecraft, where the simplicity of a system is a great asset. This technique makes it possible to follow the work function of a calibrated surface LED combination with a reproducibility of ∼2% with only one blue LED and a device to count photoelectrons. The surface described in this paper is Cs/W(110). The work function changes with time due to adsorption of residual gas in the moderate vacuum environment (in the mid 10−8 mbar range). Determination of the work function with a standard photoelectric technique is used to calibrate the system. We then derive calibration curves for this specific surface LED combination which reduce the workfunction measurement to a simple current measurement.

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Section: Introductionmentioning

confidence: 77%

Metallic work function measurement in the range 2–3.3 eV using a blue light-emitting diode source

Schletti

Würz

Fröhlich

2000

Review of Scientific Instruments

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“…The lowering of the electron work function of metals by depositing an overlayer of alkali metals onto their surfaces was first discovered by Kingdon and Langmuir [120] and has widespread applicability ranging from its use in the photocathode of photomultiplier tubes to targets for efficient production of H − ions [121]. Mills [2] suggested that Ps − emission from a carbon target is energetically favorable if the electron work function is lowered by coating it with a Cs layer, although the yield might not change greatly.…”

Section: Emission Of Ps − From Cs Coated Tungsten Surfacesmentioning

confidence: 99%

Experiments on positronium negative ions

Nagashima

2014

Physics Reports

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“…Such approaches have proven successful in describing probabilities for H − formation, especially for very low work function surfaces. 15,16 Many applications, however, do not permit the requisite level of cleanliness for a valid resonant theoretical description of ion-surface charge exchange. This is particularly true of space-based neutral atom analyzers such as the LENA (Low Energy Neutral Atom) instrument on the IMAGE satellite, 9 and in similar devices where particles are ionized via reflection from a converter surface.…”

Section: Introductionmentioning

confidence: 99%

Origin of H− in collisions of hydrogen atoms with an adsorbate-covered Cu(100) surface

DeFazio

Peko

2004

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

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Results are presented from an experimental study of electron capture and loss during collisions of low-energy hydrogen atoms and ions with a residual gas covered metal surface. Ground-state hydrogen atoms (H1s) and the atomic ions (H−,H+) were scattered from a Cu(100) surface with energies ranging from 25to200eV. Energy loss analysis indicates that the dominant process leading to H− formation proceeds directly through the adsorbed vacuum species, with the metallic crystal acting primarily as a physical scattering platform. In addition, ion beam experiments reveal effects due to the charge state of the incident particle that are inconsistent with the results expected for clean metal surfaces. Measurements indicate that the neutralization of incident ions as expected for clean metals is suppressed, a feature that is attributed to the band gap and dielectric strength of the adsorbed layer.

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The scattering of hydrogen from a cesiated tungsten surface

Cited by 111 publications

References 10 publications

Metallic work function measurement in the range 2–3.3 eV using a blue light-emitting diode source

Metallic work function measurement in the range 2–3.3 eV using a blue light-emitting diode source

Experiments on positronium negative ions

Origin of H− in collisions of hydrogen atoms with an adsorbate-covered Cu(100) surface

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