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Title: CF16 differentially pumped window for ultrahigh vacuum applications

Abstract

No abstract prepared.

Authors:
; ;  [1]
  1. I. Physikalisches Institut, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Cologne (Germany)
Publication Date:
OSTI Identifier:
20979378
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films; Journal Volume: 25; Journal Issue: 3; Other Information: DOI: 10.1116/1.2722760; (c) 2007 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; PRESSURE RANGE BELOW 1 NANO PA; PRESSURE RANGE MICRO PA; PRESSURE RANGE NANO PA; SPECTROMETERS; VACUUM SYSTEMS; WINDOWS

Citation Formats

Asvany, Oskar, Hugo, Edouard, and Schlemmer, Stephan. CF16 differentially pumped window for ultrahigh vacuum applications. United States: N. p., 2007. Web. doi:10.1116/1.2722760.
Asvany, Oskar, Hugo, Edouard, & Schlemmer, Stephan. CF16 differentially pumped window for ultrahigh vacuum applications. United States. doi:10.1116/1.2722760.
Asvany, Oskar, Hugo, Edouard, and Schlemmer, Stephan. Tue . "CF16 differentially pumped window for ultrahigh vacuum applications". United States. doi:10.1116/1.2722760.
@article{osti_20979378,
title = {CF16 differentially pumped window for ultrahigh vacuum applications},
author = {Asvany, Oskar and Hugo, Edouard and Schlemmer, Stephan},
abstractNote = {No abstract prepared.},
doi = {10.1116/1.2722760},
journal = {Journal of Vacuum Science and Technology. A, International Journal Devoted to Vacuum, Surfaces, and Films},
number = 3,
volume = 25,
place = {United States},
year = {Tue May 15 00:00:00 EDT 2007},
month = {Tue May 15 00:00:00 EDT 2007}
}
  • An ultrahigh-vacuum (UHV) differentially pumped low-energy (50--3000 eV) ion beam system for the in situ irradiation of specimens in a UHV atom-probe field-ion microscope (FIM) was designed and constructed. The ion beam system consisted of a Finkelstein-type ion source, an Einzel lens, and a magnetic mass analyzer. The ion source was connected to the analyzer chamber by small apertures which resulted in differential pumping between the ion source and the analyzer chamber; during a typical in situ irradiation of a specimen in the atom-probe FIM the total pressure was maintained at approx. =10/sup -7/ Torr. In the case of heliummore » ion irradiation the optimum ion-current density was approx. =0.5 ..mu..A cm/sup -2/ for 300-eV He/sup +/ ions at the atom-probe FIM specimen. After the completion of a helium ion irradiation the pumpdown time from 5 x 10/sup -7/ to approx. =3 x 10/sup -10/ Torr in the atom-probe FIM chamber was 0.5 h.« less
  • The FOM Institute for Plasma Physics Rijnhuizen (FOM = Foundation for Fundamental Research on Matter) has started a new line of research to study the interaction of intense plasma fluxes with a material surface. An important experimental tool for this programme will be the Magnum-PSI high-flux linear plasma generator operating in the ITER-relevant regime of plasma surface interaction (PSI). ITER is the next step in fusion reactor research (ITER is Latin for 'the way'). In Magnum-PSI a plasma beam is guided from the source to a target by a strong axial magnetic field. Besides ionized particles, the plasma source producesmore » hot neutral gas which has to be prevented from reaching the target region. In this paper it is investigated to what extent a differential pumping scheme can prevent the influx of neutral gas from the source in the target region. The results of neutral gas simulations using the Direct Simulation Monte Carlo (DSMC) method will be discussed. We will focus on the supersonic expansion as a function of background pressure and determine the influence of the skimmers on the expansion. We will demonstrate that differential pumping can be used in Magnum-PSI to reach low enough pressures in the target region. Finally, we give the optimum position of the skimmer.« less